Browse Topic: Superchargers

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Ford ‘cranks’ it up with another big V8 for Mustang19AUTP09_119/1/2019
When Ford introduced the Mustang Shelby GT350 in 2015, it was the pinnacle of Mustang-ness thanks to its 5.2-L DOHC “Voodoo” V8 that featured a flat-plane crankshaft design to enable sky-high revs (the GT350's 8200-rpm redline is one reason Ferrari has long specified flat-plane V8s) and a rollicking 526 hp at 7,500. Then there's the exotic “rip” exhaust note unique to flat-plane V8s. But contemporary musclecar development times seemingly are as quick as their ever-dropping 0-to-60 mph runs-and before Ford released the Shelby GT350, its SAE-certified 526 hp already had been eclipsed by the 707-hp supercharged 6.2-L Hemi V8 in the Dodge Challenger SRT Hellcat and later the 797-hp Hellcat Redeye. Prior to all this, GM's Chevrolet started the hyper-power frenzy by generating 650 hp from the supercharged 6.2-L OHV V8 launched for the 2012 Camaro ZL1.
Visnic, Bill
2019 Dodge Challenger: Deceased Demon seeds stronger and wider muscle-car lineup18AUTP09_109/1/2018
The 2019 Dodge Challenger lineup sees a savvy refresh that keenly redistributes its muscle-car strengths. With the one-model-year-only Demon passing into quarter-mile lore, its bawdy 808-hp supercharged V8 has been reapplied to create a more powerful Redeye version of the supercharged Challenger SRT Hellcat. Both the “regular” Hellcat and new Redeye version will be available in normal or Widebody configurations, though the shapely sheetmetal option is no longer a Hellcat exclusive. For 2019, the track-focused, naturally aspirated Challenger R/T Scat Pack trim will also be available with the wider track and fenders. The organ donation continues with a new Hemi-powered “1320” model receiving some of the Demon's drag racing tech to make it the new choice for quarter-mile aficionados.
Seredynski, Paul
Analysis of the Hardware Requirements for a Heavily Downsized Gasoline Engine Capable of Whole Map Lambda 1 Operation2018-01-09754/3/2018
MAHLE has developed a heavily downsized demonstrator engine to explore the limits, and potential benefits, of engine downsizing. The 1.2 litre, 3-cylinder, MAHLE downsizing (Di3) engine, in conjunction with an Aeristech 48 V electric supercharger (eSupercharger, eSC), achieves a BMEP level of 35 bar and a specific power output in excess of 160 kW/litre. The eSupercharger enables high specific power output, good low speed torque and excellent transient response. The resulting heavily downsized engine has been installed into a demonstrator vehicle that also features 48 V mild hybridization. At specific power output levels above 90 kW/litre the engine is operated with excess fuel in order to protect the turbine from excessive exhaust gas temperatures. In this analytical study, the boosting system requirements to maintain lambda 1 fuelling, via the use of EGR, across the entire engine operating map for the eSupercharged version of the MAHLE Di3 engine, have been explored. It has been found that a HP EGR system, with the eSupercharger located downstream of the main compressor, has the greatest potential to enable lambda 1 operation at maximum power output. At this point an EGR flow rate of 15 % is required, which would require about 38 kW of EGR cooling capability.
Bassett, Mike, Vogler, Christian, Hall, Jonathan, Taylor, James, Cooper, Adrian, Reader, Simon, Gray, Kevin, Wall, Richard
Divided Exhaust Period Implementation in a Light-Duty Turbocharged Dual-Fuel RCCI Engine for Improved Fuel Economy and Aftertreatment Thermal Management: A Simulation Study2018-01-02564/3/2018
Although turbocharging can extend the high load limit of low temperature combustion (LTC) strategies such as reactivity controlled compression ignition (RCCI), the low exhaust enthalpy prevalent in these strategies necessitates the use of high exhaust pressures for improving turbocharger efficiency, causing high pumping losses and poor fuel economy. To mitigate these pumping losses, the divided exhaust period (DEP) concept is proposed. In this concept, the exhaust gas is directed to two separate manifolds: the blowdown manifold which is connected to the turbocharger and the scavenging manifold that bypasses the turbocharger. By separately actuating the exhaust valves using variable valve actuation, the exhaust flow is split between two manifolds, thereby reducing the overall engine backpressure and lowering pumping losses. In this paper, results from zero-dimensional and one-dimensional simulations of a multicylinder RCCI light-duty engine equipped with DEP are presented. It is shown that while DEP helped reduce pumping penalty at medium and high loads, the pumping benefit was negated by crankshaft power consumption from a mechanical supercharger which made up for the boost deficit as the low exhaust enthalpy could not be efficiently utilized by a fixed geometry turbocharger (FGT). However, by replacing the FGT with a variable geometry turbocharger (VGT), a 1% improvement in brake-specific fuel consumption (BSFC) over the stock engine configuration was observed at high load, as the VGT allowed more efficient exhaust energy utilization through aspect ratio adjustment. In addition, by closing the blowdown valve at low load, higher exhaust gas temperatures were obtained by bypassing the turbocharger and thereby eliminating exhaust heat losses, which would be useful for aftertreatment thermal management.
Bharath, Anand Nageswaran, Reitz, Rolf, Rutland, Christopher
Modeling and Validation of a Roots-type Supercharger Using GT-SUITE2018-01-01644/3/2018
Superchargers are engine driven positive displacement devices which increase the air mass flow into the engine, thereby leading to a better combustion efficiency. This gives an advantage of extracting more power from the same engine [1], thereby reducing emissions and achieving a better fuel economy [2]. With emission norms getting more and more stringent, the need for boosting engine intake air becomes very important [3]. There are many types of superchargers based on design [4], out of which, the roots-type positive displacement supercharger, is discussed in here. A 1-dimensional model of supercharger gives flexibility of choosing the right aspect ratio (length to the diameter of the rotor), deciding on the clearances (a tradeoff between volumetric efficiency and manufacturing capabilities) and arriving at the inlet and discharge port dimensions. The dependency of the above parameters on mass flow rate of air and volumetric efficiency of the supercharger can be studied in good depth with a simplified one dimensional model [3]. This paper aims to present a one dimensional model of roots-type twin rotor (each 3 lobed) supercharger using pre-modeled library components on GT-Suite. This model has been validated with the test setup for different speeds and pressure ratios and is found to be accurate to the tune of min. 90% on mass flow and min. 97% on discharge temperatures. This model further assists in developing a supercharger map which helps in matching supercharger to the engine requirements.
S, Pradhan, P. K., Jeemon
Thermodynamic and Practical Benefits of Waste Energy Recovery Using an Electric Turbo-Generator Under Different Boosting Methods2018-01-08514/3/2018
This paper provides insight into the tradeoffs between exhaust energy recovery and increased pumping losses from the flow restriction of the electric turbo-generator (eTG) assessed using thermodynamic principles and with a detailed GT-Power engine model. The GT-Power engine model with a positive displacement expander model was used to predict the influence of back pressure on in-cylinder residuals and combustion. The eTG is assessed for two boosting arrangements: a conventional turbocharger (TC) and an electrically assisted variable speed (EAVS) supercharger (SC). Both a low pressure (post-turbine) and high pressure (pre-turbine) eTG are considered for the turbocharged configuration. The reduction in fuel consumption (FC) possible over various drive cycles is estimated based on the steady-state efficiency of frequently visited operating points assuming all recovered energy can be reused at an engine efficiency of 30% with 10% losses in the electrical path. On the city FTP and US06 cycles, the EAVS SC engine benefits more than the turbocharged from adding the eTG. The opposite is observed for the highway cycle where adding the eTG causes greater fuel consumption reductions for the turbocharged engine. Boost reserve in the TC case at low load, however, makes the EAVS SC with eTG (boost-by-wire) a better boosting and energy recovery system overall with reductions in FC up to 1.4%, 2.4% and 4.6% relative to the TC engine over the FTP, highway and US06 cycles respectively.
Kiwan, Rani, Middleton, Robert, Stefanopoulou, Anna
Improved Techniques in Intake Acoustic System Modeling of a Supercharged Engine2017-01-17906/5/2017
Vehicle noise emission requirements are becoming more stringent each passing year. Pass-by noise requirement for passenger vehicles is now 74 dB (A) in some parts of the world. The common focus areas for noise treatment in the vehicle are primarily on three sub-systems i.e., engine compartment, exhaust systems and power train systems. Down- sizing and down- speeding of engines, without compromising on power output, has meant use of boosting technologies that have produced challenges in order to design low-noise intake systems which minimize losses and also meet today’s vehicle emission regulations. In a boosted system, there are a variety of potential noise sources in the intake system. Thus an understanding of the noise source strength in each component of the intake system is needed. One such boosting system consists of Turbo-Super configuration with various components, including an air box, supercharger, an outlet manifold, and an intercooler. In the present work, full system level modeling is considered for dual boosting system of turbo-super configuration from an NVH perspective. The supercharger as one of the sources of intake noise was considered and noise radiation emanating from intake system was calculated. For this analysis, source impedance and strength of supercharger measured from testing are considered as inputs to the development of full system level model. There were challenges in modeling elements like the intercooler and the airbox which were addressed during development of this methodology. The system level noise prediction is presented through one way Fluid Structural Interaction (FSI) simulation. For this full system, structural FE model and duct model which is negative of the structural model is developed using acoustic FE in LMS Virtual Lab. The results are then compared with the test. This improved technique in intake acoustic modeling of a supercharged engine is useful for accurate identification and ranking of noise radiating components in the full system considered from engine inlet to air box filter.
Patil, Vinayak H., Sara, Ravi Kumar, Milind, T. R., Glover, Rodney C.
Feasibility and Design Analysis of a Pressure Wave Supercharger Adaption on a 600 cm 3 Spark Ignited Engine2017-01-10373/28/2017
This paper introduces an improved design for pressure wave superchargers used in recreational vehicles (RV) such as motorbikes or snowmobiles equipped with smaller engines. A pressure wave supercharger (PWS), commonly known as Comprex (or Hyprex), is generally used to lower the emissions. Additionally, in comparison to a standard turbocharger (TC) system, a PWS system demonstrates superior torque response behavior. However, a major disadvantage of the Comprex are its high noise emissions and expensive manufacture. For this reason, the goal of this study was to eliminate these shortcomings and to propose a new design for a pressure wave supercharger, which is simple and relatively inexpensive to produce. In this paper, the conceptual design development of this new type of PWS is presented. The methods used were the evaluation of an existing Comprex’s design and computational fluid dynamics (CFD) simulations. Though the new concept differed substantially in certain areas in comparison to a standard PWS, the working principle of the new design per se remained the same. Due to the fact, the new PWS will be driven using an electric motor, the main advantage is the reduced inertia of the running gear. While the torque response of the entire engine system remains similar to a system using a standard PWS noise emissions, fuel consumption and CO2-emissions are all reduced.
Haidinger, Christoph, Kriegler, Wolfgang, Millward-Sadler, Adrian, Eder, Philipp
Development and Implementation of a Common Rail Fuel Injection System for Flexible Combustion for an Experimental Medium Duty Diesel Engine2017-01-07903/28/2017
In order to advance the current research engine to operate in advanced combustion modes such as reactivity controlled compression ignition RCCI a diesel common rail fuel injection system for the experimental research engine has been designed and developed through testing the hydraulic, electrical and electronics, mechanical subcomponents, and the controls strategies. This study presents the process taken based on the verification and validation model of design and development for the fuel injection system incorporating hardware-in-the-loop (HIL) testing prior to engine operation and subsequent engine validation. Software verification was completed through signal converting circuits to confirm precise injection timing and to test the system in a mean effective model to incorporate a PI speed controller along with consistent rail pressure. Initial operation of the common rail system integrated on the direct injected single-cylinder medium duty engine resulted in flexible combustion schemes with various injection timings and split patterns at a constant speed of 1500 RPM and 4.2 IMEP. Swept injection timing was tested from single pulses at 8°, 15°, and 22° before top dead center (BTDC) to multiple pulses starting at 60° BTDC. The original injection was at 15° BTDC and by delaying the timing to 8° BTDC, in-cylinder pressure reduced from 71 bar to 53 bar and the AHRR (apparent heat release rate) peaks decreased from 160 J/CAD to 70 J/CAD when comparing single pulse common rail events. These changes reduced NOx emissions by 98% but in turn dramatically increased soot and unburned hydrocarbons by over 10 times. Multi-pulse injection was also tested with 30% of mass injected at 60° BTDC and 70% at 8° and 22° BTDC. The AHRR displayed cool flames at 24° BTDC along with a reduced peak at 35 J/CAD and prolonged diffusion burn. These are preliminary results on a continually growing research engine. A port fuel injector (PFI) is also introduced into the intake manifold to conduct tests in RCCI mode with alternative fuels such as various Fischer Tropsch fuels and n-butanol. The spray pattern of the new piezoelectric injector was modeled to investigate the relation with excessive soot production. The results show that the new spray pattern impinges on the cylinder head with high levels of wall wetting and film formation resulting in a slow oxidation process with increased unburned hydrocarbons, and for these reasons a custom injector is being designed to resolve this issue. The new injection system and associated controls implementation of this system allows a flexible injection scheme and combustion phasing control nevertheless, the calibration is continuing including harmonization with the EGR and supercharger systems.
Soloiu, Valentin, Gaubert, Remi, Muinos, Martin, Moncada, Jose, Beyerl, Thomas, Molina, Gustavo
A Variable Displacement Supercharger Performance Evaluation2017-01-06403/28/2017
The Variable Displacement Supercharger (VDS) is a twin helical screw style compressor that has a feature to change its displacement and its compression ratio actively during vehicle operation. This device can reduce the parasitic losses associated with supercharging and improve the relative fuel economy of a supercharged engine. Supercharging is a boosting choice with several advantages over turbocharging. There is fast pressure delivery to the engine intake manifold for fast engine torque response providing the fun to drive feel. The performance delivered by a supercharger can enable engine fuel economy actions to include engine downsizing and downspeeding. The cost and difficulty of engineering hot exhaust components is eliminated when using only an air side compressor. Faster catalyst warm up can be achieved when not warming the turbine housing of a turbocharger. To quantify these effects, a 2.0L Ford Eco-Boost® engine was chosen for an analytical comparison of three boosting configurations: turbocharged, roots style supercharged, and twin screw compressor supercharged with variable displacement. A number of partial load points were chosen to compare cycle averaged fuel consumption of the boost systems with weighting factors that represent a large SUV. Engine dynamometer testing validated the simulation results.
Wade, Robert, Murphy, Steven, Cross, Paul, Hansen, Craig
Characterization of Small-Scale Turbochargers for Unmanned Aerial Systems2016-32-007811/8/2016
Aircraft engine power is degraded with increasing altitude according to the resultant reduction in air pressure, temperature, and density. One way to mitigate this problem is through turbo-normalization of the air being supplied to the engine. Supercharger and turbocharger components suffer from a well-recognized loss in efficiency as they are scaled down in order to match the reduced mass flow demands of small-scale Internal Combustion Engines. This is due in large part to problems related to machining tolerance limitations, such as the increase in relative operating clearances, and increased blade thickness relative to the flow area. As Internal Combustion Engines decrease in size, they also suffer from efficiency losses owing primarily to thermal loss. This amplifies the importance of maximizing the efficiency of all sub-systems in order to minimize specific fuel consumption and enhance overall aircraft performance. The lack of published performance data for many commercially sold superchargers in the mass flow range of concern for this study makes selection of efficient turbo-normalization systems very difficult. This paper will present an experimental procedure for characterizing turbomachinery components for several small-scale turbochargers and superchargers of interest for the target engine, which is a small-displacement Diesel engine. Data were derived from testing these machines on an experimental stand of the authors’ design. Compressor and turbine maps created from the resulting data are presented, along with the calculated adiabatic compressor efficiencies.
Mataczynski, Mark R., Litke, Paul, Naguy, Benjamin, Baranski, Jacob
Boosting Technologies and Limits for Small Combustion Engines2016-32-007711/8/2016
Two-cylinder engines not only have special demands concerning uniformity and dynamics of oscillating masses and firing order, but also place very different demands on the turbocharger. With two-cylinder engines, the pulsating influence grows and changes the operation of the turbine. In this paper different boosting technologies are compared in small engine applications. Besides turbochargers the potentials and limits of superchargers and electric chargers are compared as well as their combinations. These technologies show differences concerning power supply, operation range and efficiency, and these effects have different implications in small engines. The efficiency of a turbo compressor, for example decreases, rapidly for small dimensions. Results from experiments and engine process simulations are shown based on a two-cylinder engine of 0.8l displacement. The operating condition of a turbocharger turbine in a two-cylinder engine is very specific due to exhaust pulsations. To understand this, a comparison was made with a four-cylinder engine based on numerical analyses. For the boundary conditions of the model, results of models from GT-Power simulations are used. Performing CFD-simulations, the turbine is driven by a two-and a four-cylinder-pulse, whereas both operations use the same specific exhaust enthalpy across one full engine cycle. In this regard, the pulsating operation of a small four-cylinder engine can be simulated and compared with those of a two-cylinder engine. The results show that for the optimization of a two-cylinder engine’s turbocharger, it is necessary to consider the specific pulse characteristics.
Baar, Roland, Boxberger, Valerius, Gern, Maike Sophie
A Study on Improvement of Fuel Economy of Heavy Duty Hybrid Trucks with New Type of Hybrid Electric Assist Engine System2016-01-235810/17/2016
In order to improve the fuel economy of the heavy duty trucks at a highway driving condition, the heavy duty hybrid trucks with new type of hybrid electric assist engine system were proposed at the previous report. The new system consists of a downsizing diesel engine with a two-stage charging structure, which has an electric supercharger with bypass circuit and a conventional turbocharger, the hybrid electric motor and the small-capacity battery. The electric power consumption of an electric supercharger is equivalent to the amount of the regeneration power produced during high-speed driving where the opportunity of the regeneration is small. In this report, an electric supercharger for the heavy duty hybrid truck was produced experimentally. First, the engine performance and exhaust emissions were investigated using the 4 cylinder diesel engine equipped with an electric supercharger. Next, the fuel economy of this heavy duty hybrid truck driving in a Japanese in-city mode and a Japanese interurban mode was investigated by using the “Hybrid Powertrain Test Bed System”.
Okui, Nobunori
Development of a Gasoline Direct Injector Fouling Test and Its Application to Study of Keep-Clean Performance at Different Additive Treat Rates2016-01-224810/17/2016
As direct injection technology in gasoline engines has become increasingly sophisticated to seek better performance, even a small amount of deposit can have a negative effect on the functionality of injectors. Against such a background, gasoline with effective additives is expected to fix this issue, however, the clean-up and keep-clean processes are not fully understood. In this study, a direct injector fouling test has been developed in order to inspect in more detail injector fouling phenomena in gasoline engines. The test engine used was a 2012 downsized supercharged direct injection spark ignition (DISI) engine equipped with an injector of maximum 15MPa injection pressure. The test fuel consisted of one regular grade gasoline (RG) and three premium grade gasoline with different concentrations of detergent. In the study, it was validated that the developed engine test generates gasoline direct injector deposit (GDID), and SEM-EDX analysis confirmed the presence of GDID inside and on the outer surface of injectors. Different concentrations of detergent showed different GDID formation tendencies under the same conditions. The fitting analysis revealed that low detergent levels are not able to keep the injector surface free of deposit, indicating that a minimum amount of detergent is required to prevent deposit formation on injectors. On the other hand, it was implied that higher concentrations of detergent could accelerate the GDID formation reaction, even though it is generally understood that addition of detergent leads to beneficial effects.
Miura, Yuichiro, Miyahara, Kensaku, Sasaki, Shinya, Kashio, Tsuyoshi, Yoshida, Katsumi
The Upper-Load Extension of a Boosted Direct Injection Poppet Valve Two-Stroke Gasoline Engine2016-01-233910/17/2016
Engine downsizing can effectively improve the fuel economy of spark ignition (SI) gasoline engines, but extreme downsizing is limited by knocking combustion and low-speed pre-ignition at higher loads. A 2-stroke SI engine can produce higher upper load compared to its naturally aspirated 4-stroke counterpart with the same displacement due to the double firing frequency at the same engine speed. To determine the potential of a downsized two-cylinder 2-stroke poppet valve SI gasoline engine with 0.7 L displacement in place of a naturally aspirated 1.6 L gasoline (NA4SG) engine, one-dimensional models for the 2-stroke gasoline engine with a single turbocharger and a two-stage supercharger-turbocharger boosting system were set up and validated by experimental results. The simulation results show that when a single-stage turbocharger with wastegate is used in the two-cylinder 2-stroke poppet valve gasoline engine, a compressor with high pressure ratio at low mass flow rate should be selected in order to maintain the positive pressure difference between intake and exhaust ports. The maximum brake torque of the turbocharged 2-stroke gasoline engine cannot reach that of the NA4SG engine at 1000 rpm and 1500 rpm. Its maximum brake power at 3000 rpm is lower than that of the NA4SG engine at 6000 rpm. However, in the case of two-stage serial boosting system with a supercharger and a downstream turbocharger, the 2-stroke poppet valve gasoline engine can produce the torque and power of the NA4SG engine.
Fu, Xue-Qing, He, Bang-Quan, Zhao, Hua
Volvo S90: Niche for now, but…16AUTP10_1110/1/2016
It's no secret the reconstituted Volvo, since 2010 owned by China's Zhejiang Geely, is doing interesting and innovative things-one of the most intriguing, maybe, being that it's survived and in some senses thrived (particularly if fellow Swedish auto brand Saab is used as a measure) under Geely's control. Fact is that Volvo and Geely have shut up the naysayers: in the nearly seven years Geely's been in charge, a studied and benevolent guidance (not to mention $11 billion in product-development funding announced in 2012) has delivered a Volvo that's somehow managed to evolve its brand back to a relevancy few thought it could ever recover.
Visnic, Bill
Developing a Performance Specification for an Electric Supercharger to Satisfy a Range of Downsized Gasoline Engine Applications2016-01-10414/5/2016
Extreme engine downsizing is a modern solution aimed towards the goal of meeting new emissions regulations for internal combustion engines. A higher percentage downsized engine will produce less CO2. By extension, a higher boost level is required to generate high engine torque performance. The transient load step of a higher boost system at low RPM is currently an issue for conventional boosting. Aeristech has developed an electric supercharger to be matched with a conventional turbocharger to create a new type of two stage boosting system and a simpler downsized gasoline engine usable in mainstream vehicle segments. Whereas most electric pressure charging devices are capable of transient output to alleviate turbo lag. The electric supercharger is capable of steady-state air delivery. This makes the electric supercharger a dual-function device, alleviating turbo lag and also supplementing the compressor map of the turbocharger or main boost device. The electric supercharger thus acts as a conventional mechanical supercharger in addition to a conventional electric pressure charging device. Accordingly, the electric supercharger can replace a turbocharger stage within a multi-stage turbocharger arrangement. This functionality was simulated on a 2L boosted premium gasoline engine [1], and tested on a 1.2L extreme downsized engine [2]. There are currently two primary designs of electric supercharger: one uses separate motor and power electronics and the second incorporates the electronics as a single package. The compressor alone achieves a wide map width and 80% peak efficiency whilst the combined motor and power electronics are able to deliver full load in less than 0.5s. The design was optimised to minimise the specific volume and to improve packing flexibility within the vehicle. In addition, the electric supercharger has been tested on MAHLE’s electric supercharged Di3 engine. This engine produces high specific power of 161kW/L and a substantially flat torque curve across the engine’s speed range [2].
Tran, Hiep Hoang, Richard, Bryn, Gray, Kevin, Hall, Jonathon M.
Comparison of Supercharging Concepts for SI Engine Downsizing2016-01-10324/5/2016
The paper reviews the design of the supercharging system for a strongly downsized engine, to be installed on a sport car. Design is supported by cfd-1d engine simulations, using an experimentally calibrated model. The goal of the supercharging system is to deliver the required values of boost pressure at steady operating conditions, and to maintain or improve the full size engine response during acceleration (one of the most critical issues for downsized engines). Two options have been considered: 1) two-stage turbocharging, with two small turbochargers as a high-pressure stage, and one big turbo as low pressure stage (referred to as “TRITURBO”; 2) two-stage supercharging made up of one low pressure stage turbocharger and one electric supercharger (referred to as “E-SUPER”). It was found that both configurations not only allow the downsized engine to comply with the performance targets at wide open throttle, steady conditions, but they are also able to improve the transient response in comparison to the full size engine. TRITURBO is less expensive than E-SUPER, but also less fuel efficient and more difficult to install on the vehicle.
Mattarelli, Enrico, Rinaldini, Carlo Alberto, Agostinelli, Enrico
Coding, Evaluation, Comparison, Ranking and Optimum Selection of Supercharger2016-01-02934/5/2016
The paper expresses an important issue of optimum selection of a supercharger for a given application from the global market in the presence of a variety of superchargers available commercially off the shelf (COTS). Coding scheme suggested is based on developing an attribute based scheme for all superchargers available off the shelf. N-digit coding scheme provides in-depth understanding of all the attributes to be considered by the customers, designers, engineers and engineers of the industry for further improvement. We also aim to create exhaustive database of superchargers along with their attributes. The paper adopts a MADM-TOPSIS (Multiple Attribute Decision Making -Technique for Order of Preference by Similarity to Ideal Solution) technique and graphical methods that are being used widely in different disciplines and are published. The method ensures that the optimum supercharger is closest to the hypothetically best solution and farthest from the worst solution. This technique can easily be extended to other components and subsystems of automobile vehicles. The technique is also illustrated by an example.
Singh, Jaspreet, Agrawal, Vishnu
Comparison of High- and Low-Pressure Electric Supercharging of a HDD Engine: Steady State and Dynamic Air-Path Considerations2016-01-10354/5/2016
This paper numerically investigates the performance implications of the use of an electric supercharger in a heavy-duty DD13 diesel engine. Two electric supercharger configurations are examined. The first is a high-pressure (HP) configuration where the supercharger is placed after the turbocharger compressor, while the second is a low-pressure (LP) one, where the supercharger is placed before the turbocharger compressor. At steady state, high engine speed operation, the airflows of the HP and LP implementations can vary by as much as 20%. For transient operation under the Federal Test Procedure (FTP) heavy duty diesel (HDD) engine transient drive cycle, supercharging is required only at very low engine speeds to improve airflow and torque. Under the low speed transient conditions, both the LP and HP configurations show similar increases in torque response so that there are 44 fewer engine cycles at the smoke-limit relative to the baseline turbocharged engine. When the requested engine torque rise rate is increased from the FTP ramps to steps, the benefit of supercharging is extended to also include mid-range engine speeds, with over ∼ 70% fewer cycles at the smoke-limit line. In addition, the results show an improvement in the overall fuel economy of the supercharged engine during low engine speed transients compared to the baseline turbocharged engine. The study highlights the importance of supercharger by-pass valve control, where the transient response of the valve should be twice as fast as the electric supercharger drive motor for accurate and minimal supercharger power consumption during transient maneuvers. Finally, an engine re-calibration with increased exhaust gas recirculation at low engine speeds/loads, resulted 4.6% fuel economy improvements at that low speed/load region while the supercharger enabled fast air-flow increase during aggressive tip-ins.
Salehi, Rasoul, Martz, Jason, Stefanopoulou, Anna, Hansen, Taylor, Haughton, Andrew
SuperGen - A Novel Low Costs Electro-Mechanical Mild Hybrid and Boosting System for Engine Efficiency Enhancements2016-01-06824/5/2016
SuperGen is a Belt Integrated Starter Generator (B-ISG) combined with a novel electro-mechanical power split transmission system providing variable speed centrifugal supercharger capability, all in one compact package. This paper initially discusses the analysis of SuperGen application to a gasoline SUV in order to examine the BISG power and voltage mild hybrid functionality trade-off versus fuel consumption reduction on drive cycle. A significant engine down speeding was also applied based on the low speed torque enhancement afforded by SuperGen boosting capability, both transiently, and sustainably at steady state engine operation. This has been demonstrated and reported on the well-published Jaguar Land Rover (JLR) Ultraboost project. Finally, the part load “boost-ondemand” was used to evaluate advanced combustion modes not easily achievable with conventional turbocharger technology, namely; aggressive Miller cycle with early inlet valve closing; EGR diluted stoichiometric homogenous operation and un-throttled lean stratified combustion.
King, Jason, Barker, Luke, Turner, James, Martin, John
Synchronization and Visualization of Arbitrary Streams (SAVORS)TBMG-236851/1/2016
The purpose of SAVORS is to supercharge the command-line tools already used by administrators with powerful visualizations that help them understand the output much more rapidly and with far greater scalability across systems. SAVORS not only supports the output of existing commands, but does so in a manner consistent with those commands by combining the line-editing capabilities of vi, the rapid window manipulation of GNU screen, the power and compactness of Perl expressions, and the elegance of UNIX pipelines.
Chassis Development for the Motorcycle With High Power Output Supercharged Engine2015-32-072311/17/2015
In motorcycles, the size and output performance of the engine itself has a major effect on the maneuverability of the motorcycle. In particular for cases where a high output engine is mounted on a lightweight frame, these effects are even more of a concern. In the case of developing a racing motorcycle with a high power engine, the behavior of the motorcycle differs depending on the output range used and there are a lot of cases where changes to the basic dimensions of the motorcycle as well as the main components are required. Here, there are a lot of cases where the rider and drive-able courses are limited to compatibility with distinct specifications and when considering use as a general mass production motorcycle by riders with varying levels of skills and in various environments, it difficult to determine how to provide support. In the case of installing a high output engine on a general mass production motorcycle that is not for racing, ensuring of robustness of motorcycle behavior related to engine characteristics to the extent possible while providing the rider a feeling of comfort even if there is noise to enable enjoying driving at high output are of utmost importance. Also, in a high output engine the amount of heat generated by the engine is extensive and management of this heat is important to ensure comfort of the rider. Similarly, appropriate aerodynamic management in conjunction with increase in traveling speed is also important to ensure motorcycle stability and comfort. For general purpose motorcycles, ensuring of robustness relative to speed range and driving style as well as reducing driving resistance are important as well. This report describes the motorcycle chassis for the first general purpose mass production motorcycle in the world to use a supercharged engine that generates high output and describes important technology elements used to package this general purpose motorcycle that enable achieving both stability and high maneuverability.
Ishii, Hiroshi, Saeki, Daisuke, Yamamoto, Tomo, Morikawa, Manabu, Sakurada, Eiji, Ichikawa, Kazuhiro, Sonoda, Seiichi, Nagata, Taku, Kimura, Toshiyuki
Development of a Supercharged Engine for Motorcycle with a Centrifugal Supercharger2015-32-072911/17/2015
1 In the development of motorcycle engines, a strong feeling of power, an element of being fun to ride has continued strong demand. However, demand to meet environmental performance, a conflicting element, has increased dramatically in recent years and a breakthrough technology that achieves both environmental performance and a feeling of power is in demand. Here, the newly developed engine has greatly enhanced feeling of power while clearing stringent environmental restrictions through use of a centrifugal type supercharger. However, there were several problems that had to be resolved with regards to application of a supercharger to a motorcycle engine. In applying a supercharger to a motorcycle, a major problem is the best way to keep the engine size from increasing in size. The engine, which is the heaviest parts on a motorcycle greatly affects motorcycle maneuverability so it must be compact and the mass concentrated. Another one of the problems was suppression of knocking to the extent possible. An intercooler for cooling intake air is generally used as a countermeasure for knocking in supercharged engines. However, increase in size and weight of the motorcycle through use of an intercooler was cause for a significant loss in the fun to ride aspect and thus was difficult to permit. For this model, by increasing the supercharging efficiency of the supercharger and matching it to the engine characteristics suppression of intake air temperature and thus knocking was achieved. In addition, a layout that maximizes efficiency of the supercharger and that is beneficial to operability of the motorcycle was sought out. This report describes various technologies used to resolve problems that arise when applying a centrifugal supercharger to a motorcycle engine.
Watanabe, Hiroyuki, Ichi, Satoaki, Saito, Masahito, Arima, Kazuki, Ishibashi, Yasushi
Analysis for Influence of Inhomogeneity of Air-Fuel Mixture to Super-Knock Caused by Pre-ignition in Supercharged Direct-Injected SI Engine Based on Numerical Calculation2015-01-18669/1/2015
Nowadays, highly super charging is required corresponded to downsizing concept for improving thermal efficiency in direct-injected spark ignition (DISI) engine. However, highly super charging increases the possibility of super-knock caused by pre-ignition. Recently, in many studies, the reason of pre-ignition has been investigated but the reason why pre-ignition leads such strong knocking called super-knock has not been investigated. In DISI engine, it is estimated that there is more inhomogeneity of equivalence ratio and temperature of air-fuel mixture than it in port injection SI engine. In this study, factors which decide self-ignition timing was reviewed and the influence of inhomogeneity of air-fuel mixture to super-knock was investigated based on numerical calculation.
Negoro, Keito, Seki, Yuichi, Nishi, Mina, Iida, Norimasa, Matsuura, Katsuya, Sato, Yoshihisa
Thermal Efficiency Enhancement of a Gasoline Engine2015-01-12634/14/2015
The goal of this research was to improve thermal efficiency under conditions of stoichiometric air-fuel ratio and 91 RON (Research Octane Number) gasoline fuel. Increasing compression ratio and dilution are effective means to increase the thermal efficiency of gasoline engines. Increased compression ratio is associated with issues such as slow combustion, increased cooling loss, and engine knocking. Against these challenges, a higher stroke-bore ratio (S/B ratio) and a lower effective compression ratio were tried as countermeasures. With respect to increased dilution, combustion of a high-EGR (Exhaust Gas Recirculation) was tried. High-energy ignition and optimized combustion chamber shape with high tumble port were tried as countermeasures against slow combustion and reduced ignitability due to a higher EGR rate. As a result of this study on single cylinder engine, a brake thermal efficiency of 45% was achieved at an engine speed of 2000 rpm with a S/B ratio of 1.5, a compression ratio of 17, an effective compression ratio of 12.5, and an EGR rate above 30%. Application to a four-cylinder engine was investigated, taking into account factors such as an engine height, effects between cylinders and the impact of a supercharger on the intake and exhaust systems.
Ikeya, Kenichiro, Takazawa, Masanobu, Yamada, Taketo, Park, Shinrak, Tagishi, Ryutaro
A New De-throttling Concept in a Twin-Charged Gasoline Engine System2015-01-12584/14/2015
Throttling loss of downsized gasoline engines is significantly smaller than that of naturally aspirated counterparts. However, even the extremely downsized gasoline engine can still suffer a relatively large throttling loss when operating under part load conditions. Various de-throttling concepts have been proposed recently, such as using a FGT or VGT turbine on the intake as a de-throttling mechanism or applying valve throttling to control the charge airflow. Although they all can adjust the mass air flow without a throttle in regular use, an extra component or complicated control strategies have to be adopted. This paper will, for the first time, propose a de-throttling concept in a twin-charged gasoline engine with minimum modification of the existing system. The research engine model which this paper is based on is a 60% downsized 2.0L four cylinder gasoline demonstrator engine with both a supercharger and turbocharger on the intake. The idea is to use a CVT driven supercharger to ‘throttle’ the intake mass flow. By the adoption of a CVT, the supercharger outlet pressure could be controllable. Depending on whether the outlet pressure is larger than the inlet, the supercharger could supply boost at high load consuming engine power or behave like an expander under part load presenting a means to recover the throttling loss to provide all the necessary need. A 1-D simulation model was used for this research with some experimental data of the supercharger functioned as an expander from a test rig. The results showed that at part load, by recovering some throttling loss through the supercharger, up to 3% BSFC improvement could be achieved compared to the throttled counterpart depending on the engine operating points. The effect of the reduced supercharger outlet temperature on the combustion efficiency was also discussed. It showed in the end that by the speed control, extended working range of the supercharger can be achievable which could push the fuel efficiency of the downsized engine further.
Hu, Bo, Copeland, Colin, Lu, Pengfei, Akehurst, Sam, Brace, Chris, Turner, J.W.G, Romagnoli, Alessandro, Martinez-Botas, Ricardo
SuperGen on Ultraboost: Variable-Speed Centrifugal Supercharging as an Enabling Technology for Extreme Engine Downsizing2015-01-12824/14/2015
The paper discusses investigations into improving the full-load and transient performance of the Ultraboost extreme downsizing engine by the application of the SuperGen variable-speed centrifugal supercharger. Since its output stage speed is decoupled from that of the crankshaft, SuperGen is potentially especially attractive in a compound pressure-charging system. Such systems typically comprise a turbocharger, which is used as the main charging device, compounded at lower charge mass flow rates by a supercharger used as a second boosting stage. Because of its variable drive ratio, SuperGen can be blended in and out continuously to provide seamless driveability, as opposed to the alternative of a clutched, single-drive-ratio positive-displacement device. In this respect its operation is very similar to that of an electrically-driven compressor, although it is voltage agnostic and can supply other hybrid functionality, too. In the work reported here a prototype SuperGen unit was tested on the Ultraboost extreme downsizing demonstrator engine and the performance compared to that of the originally-specified positive-displacement device. This engine has previously been described in detail and represents a 60% downsizing factor versus a 5.0 litre naturally-aspirated V8, although the ‘standard’ baseline combination of supercharger and turbocharger was found in earlier work to be a limitation on achieving the full downsizing factor at low engine speed. The improvement in full-load performance in the area where the turbocharger cannot generate the required boost by itself is reported. The transient response of the combined system at low engine speed is also presented, together with part-load fuel economy data at several engine speed and load points. Finally, this part-load data is used for vehicle modelling work showing that a more-efficient high-pressure stage can bring further fuel economy benefits to extremely-downsized vehicle applications.
Turner, J.W.G., Popplewell, A., Marshall, D.J., Johnson, T.R., Barker, L., King, J., Martin, J., Lewis, A.G.J., Akehurst, S., Brace, C.J., Copeland, C.D.
Explore and Extend the Effectiveness of Turbo-compounding in a 2.0 litres Gasoline Engine2015-01-12794/14/2015
After years of study and improvement, turbochargers in passenger cars now generally have very high efficiency. This is advantageous, but on the other hand, due to their high efficiency, only a small portion of the exhaust energy is needed for compressing the intake air, which means further utilization of waste heat is restricted. From this point of view, a turbo-compounding arrangement has significant advantage over a turbocharger in converting exhaust energy as it is immune to the upper power demand limit of the compressor. However, with the power turbine being located in series with the main turbine, power losses are incurred due to the higher back pressure which increases the pumping losses. This paper evaluates the effectiveness that the turbo-compounding arrangement has on a 2.0 litres gasoline engine and seeks to draw a conclusion on whether the produced power is sufficient to offset the increased pumping work. Furthermore, as mentioned above, the baseline engine model in this paper is not a heavy-duty diesel engine which is more appropriate to the turbo compounding mechanism for automotive application, but a small size gasoline engine. This paper also aims to explore a potential methodology for extending the operating range of the turbo compounding in light-duty petrol engine over its entire speed range under full load condition. The system models in this paper were built in GT-Power which is a one dimension (1-D) engine simulation code. Simulation results show that with the assistance of a variably driven supercharger, the output torque of the engine system is much larger (up to around 24%) at lower engine speeds. The fuel economy is also improved by up to about 8%.
Lu, Pengfei, Brace, Chris, Hu, Bo
Two-Stroke Gasoline Engines for Small-Medium Passenger Cars2015-01-12844/14/2015
Among all the reciprocating internal combustion engines, gasoline two-strokes can reach the highest specific power, making this technology a natural enabler of downsizing and/or down-speeding. In addition, multi-cylinder 2-stroke engines may be an ideal match for electrical superchargers, providing very efficient power units. The paper explores through CFD-1d simulations and empirical hypotheses the potential of a 3-cylinder, 1.0 liter, GDI 2-stroke turbocharged engine featuring a patented rotary valve for the optimization of the scavenging process, the latter being of the loop type (piston-controlled ports). The lubrication system is the same of a 4-stroke engine (no crankcase pumps). The supercharging system is made up of a turbocharger and an electric compressor, serially connected. The power of the electric compressor is limited to 2 kW, in order to comply with standard automotive 12 V electric systems. The proposed engine easily achieves the goal of 95 kW at 4500 rpm, and 210 Nm at 1500 rpm, resulting also quite fuel efficient at any operating conditions (best point: 211 g/kWh, achieved with stratified charge).
Mattarelli, Enrico, Rinaldini, Carlo Alberto
A New Turboexpansion Concept in a Twin-Charged Engine System2014-01-259610/13/2014
Engines equipped with pressure charging systems are more prone to knock partly due the increased intake temperature. Meanwhile, turbocharged engines when operating at high engine speeds and loads cannot fully utilize the exhaust energy as the wastegate is opened to prevent overboost. The turboexpansion concept thus is conceived to reduce the intake temperature by utilizing some otherwise unexploited exhaust energy. This concept can be applied to any turbocharged engines equipped with both a compressor and a turbine-like expander on the intake loop. The turbocharging system is designed to achieve maximum utilization of the exhaust energy, from which the intake charge is over-boosted. After the intercooler, the turbine-like expander expands the over-compressed intake charge to the required plenum pressure and reduces its temperature whilst recovering some energy through the connection to the crankshaft. It is anticipated that such a concept has benefits for knock resistance and energy recovery despite suffering higher pumping losses. This paper, for the first time, will investigate the net fuel efficiency benefit from this concept using a super-turbo twin-charger 1-D simulation model. By the operation of a switch between compressor and expander mode, the supercharger could provide boost at low engine speed whilst behaving like a turbine presenting an indirect means to recover exhaust gas energy at high engine speed and meanwhile reducing the intake temperature. The results showed that the BSFC improvement depended on the efficiency of the supercharger as an expander.
Hu, Bo, Copeland, Colin, Brace, Chris, Akehurst, Sam, Romagnoli, Alessandro, Martinez-Botas, Ricardo, Turner, J.W.G
Design, Simulation, and Testing of a Pressure Wave Supercharger for a Small Internal Combustion Engine2014-01-21369/16/2014
The engines used to power small unmanned aerial systems are often modified commercial products designed for use by hobbyists on small model aircraft at low altitude. For military applications, it is desirable to fly at high altitudes. Maintaining power from the engine at the reduced ambient air pressures associated with high altitudes requires some method of increasing air delivery to the intake manifold. Conventional turbochargers and superchargers are typically very inefficient for the low mass flows associated with small engines. Due to its unique characteristics, a pressure wave supercharger (PWS) can avoid many scaling-related losses. This project designed a small-scale PWS for turbo-normalization of a Brison 95 cc two-stroke engine for a small unmanned aerial vehicle. A larger PWS called the Comprex®, designed by Brown Boveri Company, was simulated using a quasi-one-dimensional Computational Fluid Dynamics (CFD) code developed at the NASA Glenn Research Center. This code was able to predict the mass flow, temperature ratio, and pressure ratio at each respective port to within 2%, 6% and 18%, respectively when compared to test results. With the code validated for the performance of the Comprex®, the design point and several off-design points of the small-scale rotor were simulated, indicating acceptable performance. The design was then modeled using SolidWorks and the major parts were manufactured via an additive direct metal laser sintering process. A test rig has been built for the purpose of comparing the computational results of the CFD code to the data gathered during testing. Initial simulations indicate that for standard sea level ambient conditions, the scaled pressure wave supercharger will supply air to the intake manifold of the Brison at 38 psia (a pressure ratio of 2.5). This suggests that an inlet pressure of approximately 25 psia could be supplied to the engine if it were operating at 10,000 ft above sea level, where the ambient air pressure is 10.1 psia. Once construction of the test rig is completed, testing will indicate the extent of loss and the real overall performance for the device designed.
Mataczynski, Mark, Hoke, John, Paxson, Daniel, Polanka, Marc D.
Engine Parameter Optimization for Improved Engine and Drive Cycle Efficiency for Boosted, GDI Engines with Different Boosting System Architecture2014-01-12044/1/2014
As boosted, direct injected gasoline engines become more prevalent in the automotive market, the boosting system architecture and efficiency are intimately entwined with the efficiency and performance of the engine. Single-stage as well as two-stage boosting systems, comprising of either two turbochargers or a supercharger in combination with a turbocharger, are potential configurations. When combining an internal combustion engine with boosting hardware, a mechanical, fluid-dynamic and thermodynamic coupling is created and the system as a whole will need to be treated as such. For the initial selection of the boost system, it is important to match all of the engine design features, such as the engine's compression ratio, valve profiles and intake and exhaust components as well as to adjust and optimize all engine controls' calibration parameters. 1-D engine cycle simulations in combination with engine experimental testing were utilized to explore optimum engine configurations and calibration settings when using a variety of boosting systems. A total of five different engine and boosting configurations where configured for this project, including two 4-cylinder, 1.6 liter GDI gasoline engines with single stage boosting (turbocharging and supercharging) and three downsized, 3-cylinder, 1.2 liter GDI gasoline engines with two-stage boosting configurations (series-sequential twin-turbo, super-turbo and turbo-super). Design-of-Experiment routines were carried out to optimize both fixed engine hardware specifications, e.g. compression ratio, as well as variable parameters, e.g. intake and exhaust valve phasing, combustion phasing, for a given boost system architecture on the target engine. Fuel economy and performance comparison were conducted between the different engine and boost system architectures for steady-state operating conditions as well as for common vehicle drive cycles. For light load operating conditions and lightly loaded test cycles e.g. NEDC), the downsized engines with two-stage boosting systems, particularly the 3-cylinder engine with super-turbo configuration, offered the greatest fuel economy potentials. For mid and high load operating conditions and more highly loaded test cycles (e.g. US06), the 4-cylinder, supercharged arrangement offered best fuel economy potentials. For steady-state, high load operating conditions, the 4-cylinder, turbocharged arrangement yielded best fuel consumption values.
Amann, Manfred, Ouwenga, Daniel
Mechanically Supercharged 2.4L GDI Engine for Improved Fuel Economy and Low Speed Torque Improvement2014-01-11864/1/2014
This paper describes the simulation, design, and testing of a mechanically supercharged 2.4L I-4 gasoline direct injection engine with Miller cycle late intake valve closing and high geometric compression ratio. Engine downspeeding is also achieved through modified transmission gear ratios. A 3.3L naturally-aspirated V6 engine was chosen as the benchmark for comparison. Intended vehicle application is a mid-size passenger car or small/mid-size CUV. The CAE tool GT-Power was used for component selection and air path development. The powertrain simulation model was then exercised to show both improved fuel economy and performance compared to the V6 baseline engine. The design of a bespoke integrated supercharger with magnetic clutch, charge air cooler, and intake manifold was made and procured. A large new software aggregate was ported into an existing production ECU with modified internal circuitry. Volumetric efficiency was calibrated using automated engine mapping techniques and software. Data reduction methods compiled the raw outputs into a point-slope format. A full factorial design of experiments yielded models for the most potent calibration areas. Engine dynamometer results show promising fuel economy improvement under simulated FTP drive cycles. Development for supercharger clutch control and in-vehicle testing is currently in progress.
Birckett, Aaron, Engineer, Nayan, Arlauskas, Paul, Shirley, Mark, Neuman, Paul
TVS® V-Series Supercharger Development for Single and Compound Boosted Engines2013-01-09194/8/2013
In response to the continued industry trend towards downsized, downsped gasoline and diesel engines, Eaton has continued to create and optimize small displacement TVS® Superchargers for volumetric and isentropic efficiency at low speeds. Such efficiency improvements enable maximum engine torque at very low engine speeds in both transient and steady state conditions. Development of the V-Series has primarily focused on units in the 250 cc to 400 cc displacement range, with applications both as a single boost device, and as an element in a compound boost system. Key parameters such as rotor length, diameter and helix angle, as well as inlet and outlet port geometry have been optimized for performance and NVH characteristics. This paper will summarize the performance, packaging, and NVH of V-Series TVS® superchargers compared to R-Series TVS® superchargers and outline the end benefits that this can provide to customers. V-Series has demonstrated a low speed volumetric efficiency improvement of up to 18%.
Froehlich, Michael, Stewart, Nathan
Development of High Speed Motor and Inverter for Electric Supercharger2013-01-09314/8/2013
In recent years, the fuel consumption improvement of automobiles is indispensable due to the global move to reduce CO₂ emissions. Downsizing of engines by turbocharger obtains the output equal to a large engine, and improves the fuel consumption. However, turbocharger has the response delay called turbo lag. In order to improve a transient response, we developed a high-speed motor. The electric supercharger consists of high-speed motor and compressor, and drives compressor by high-speed motor instead of an exhaust gas turbine. By combining conventional turbocharger and electric supercharger, we developed two-stage turbocharger system. In this paper, we explained development of high-speed motor and inverter. And, as application example, we explained electric two-stage turbocharger system. The high-speed motor and inverter are connected without harness, and assembled in one single unit. The motor is driven at high efficiency by vector control. The performance test shows a high speed response of 0.7 sec acceleration time from zero to maximum speed 90,000 rpm. Electric two-stage turbocharger, applying high-speed motor, is evaluated by engine simulation tool (GT-Power) and engine bench test. As a result of engine test using a 1.5-liter gasoline engine, the electric two-stage turbocharger demonstrated the 43% improvement in a response time at 1500 rpm, compared with normal two-stage turbocharger. This experiment shows that electric supercharger is effective to improve transient response. It is expected to contribute ever tightening CO₂ reduction with automobile engines from now on.
Nishiwaki, Kazuhiro, Iezawa, Masahiro, Tanaka, Hideyuki, Goto, Takashi, An, Byeongil
1-D Model of Roots Type Supercharger2013-01-09274/8/2013
This paper introduces research work on 1-D model of Roots type supercharger with helical gears using 1-D simulation tool. Today, passenger car engine design follows approach of downsizing and the reduction of number of engine cylinders. Superchargers alone or their combination with turbochargers can fulfill low-end demands on engine torque for such engines. Moreover, low temperature combustion of lean mixture at low engine loads becomes popular (HCCI, PCCI) requiring high boost pressure of EGR/fresh air mixture at low exhaust gas temperature, which poses too high demands on turbocharger efficiency. The main objective of this paper is to describe Roots charger features and to amend Roots charger design. The presented analysis tool is a 1-D model of Roots type supercharger respecting inlet and outlet processes due to the change of volume between teeth, fast compression in the gap between teeth after connecting the compressor outlet, mass flow losses caused by teeth mesh and casing clearances and additional compression/expansion between meshing-in teeth. Finding the geometrical data (variable volumes, surfaces and cross-section areas) is based on newly developed procedures using scripts in 3-D solid CAD model, in which teeth meshing was simulated. The developed model has been calibrated using supercharger map measured at a test rig. The model constructed from 1-D model modules has been used for sensitivity analysis considering design data. It can be connected to engine model and easily used for supercharger map extrapolation.
Brynych, Pavel, Macek, Jan, Vitek, Oldrich, Cervenka, Libor
Combustion and Emissions with Bio-alcohol and Nonesterified Vegetable Oil Blend Fuels in a Small Diesel Engine2012-32-001710/23/2012
Combustion and exhaust gas emissions of alcohol and vegetable oil blends including a 20% ethanol + 40% 1-butanol + 40% vegetable oil blend and a 50% 1-butanol + 50% vegetable oil blend were examined in a single cylinder, four-stroke cycle, 0.83L direct injection diesel engine, with a supercharger and a common rail fuel injection system. A 50% diesel oil + 50% vegetable oil blend and regular unblended diesel fuel were used as reference fuels. The boost pressure was kept constant at 160 kPa (absolute pressure), and the cooled low pressure loop EGR was realized by mixing with a part of the exhaust gas. Pilot injection is effective to suppress rapid combustion due to the lower ignitability of the alcohol and vegetable oil blends. The effects of reductions in the intake oxygen concentration with cooled EGR and changes in the fuel injection pressure were investigated for the blended fuels. Also, the operation with all the blended and reference fuels with optimized pilot quantities and suitable EGR rates was investigated over a wide range of IMEP 1.0 MPa. Silent, low NOx, and smokeless combustion is possible over a wide IMEP range with the alcohol and vegetable oil blended fuels here with optimized quantities of pilot injection and EGR rates. Premixed combustion with pilot injection occurs near TDC with the alcohol + vegetable oil blended fuels due to the poor ignitabilities, which make it possible to increase the quantity of pilot injection and reduce the after burning with the main injection, resulting in improvements in the indicated thermal efficiency due to the increase in the degree of constant volume heat release. Smokeless operation is possible with the alcohol and vegetable oil blends even at low injection pressure and large EGR rate conditions.
Ogawa, Hideyuki, Setiapraja, Hari, Hara, Kosuke, Shibata, Gen
Development of New I3 1.2L Supercharged Gasoline Engine2012-01-04154/16/2012
This paper describes a new 1.2-liter three cylinder gasoline engine named HR12DDR, with the target to achieve the lowest level CO2 in the European B-segment market and also, to satisfy the customer's driving pleasure through high output performance. This engine is developed with the consideration of meeting further strict regulations in the years ahead and of the possibility of being an alternative powertrain of diesel in the future as well. As a first step this engine was applied on the European Nissan Micra in 2011; achieving 95g/km CO2 emissions(NEDC mode). This low fuel consumption was realized mainly through technologies which scope to maximize thermal efficiency with high compression ratio, and to minimize the mechanical friction loss. The combustion was optimized by Direct injection (DI)system. To obtain the better fuel economy performance without sacrificing high output, we chose the supercharger system with bypass valve and electromagnetic clutch. Details of the HR12DDR are presented here along with highlights of the applied technologies.
Kobayashi, Atsushi, Satou, Takeshi, Isaji, Hiroshi, Takahashi, Sho, Miyamoto, Takeshi
Downspeeding and Supercharging a Diesel Passenger Car for Increased Fuel Economy2012-01-07044/16/2012
The effects of downspeeding and supercharging a passenger car diesel engine were studied through laboratory investigation and vehicle simulation. Changes in the engine operating range, transmission gearing, and shift schedule resulted in improved fuel consumption relative to the baseline turbocharged vehicle while maintaining performance and drivability metrics. A shift schedule optimization technique resulted in fuel economy gains of up to 12% along with a corresponding reduction in transmission shift frequency of up to 55% relative to the baseline turbocharged configuration. First gear acceleration, top gear passing, and 0-60 mph acceleration of the baseline turbocharged vehicle were retained for the downsped supercharged configuration.
Ostrowski, Gregory, Neely, Gary D., Chadwell, Christopher J., Mehta, Darius, Wetzel, Philip
Experimental Study into a Hybrid PCCI/CI Concept for Next-Generation Heavy-Duty Diesel Engines2012-01-11144/16/2012
This paper presents the first results of an experimental study into a hybrid combustion concept for next-generation heavy-duty diesel engines. In this hybrid concept, at low load operating conditions, the engine is run in Pre-mixed Charge Compression Ignition (PCCI) mode, whereas at high load conventional CI combustion is applied. This study was done with standard diesel fuel on a flexible multi-cylinder heavy-duty test platform. This platform is based on a 12.9-liter, 390 kW heavy-duty diesel engine that is equipped with a combination of a supercharger, a two-stage turbocharging system and low-pressure and high-pressure EGR circuitry. Furthermore, Variable Valve Actuation (VVA) hardware is installed to have sufficient control authority. Dedicated pistons, injector nozzles and VVA cam were selected to enable PCCI combustion for a late DI injection strategy, free of wall-wetting problems. The decision to use a multi-cylinder configuration instead of a single-cylinder research engine was taken because this allows to assess the impact of limitations in operating range of current turbocharger equipment and that of cylinder interaction. It also allowed to assess control issues relevant for future production engines. First results are shown for four low load ESC operating points. Injection timing, EGR rate and effective compression ratio are varied to find suitable PCCI operating conditions with this equipment. The effect of these control parameters on combustion phasing, heat release, emissions (NO , HC, CO, smoke), and fuel consumption is presented. Similar trade-offs are determined for conventional CI combustion at higher loads. From the experimental results, it is concluded that PCCI combustion is successfully realized up to 25% load, corresponding to 5.6 bar BMEP. Further optimization of TC matching and combustion is needed to improve PCCI fuel efficiency and especially high load CI operation.
Doosje, Erik, Willems, Frank, Baert, Rik, Van Dijk, Martin
Air System Conception for a Downsized Two-Stroke Diesel Engine2012-01-08314/16/2012
This paper introduces a research work on the air loop system for a downsized two-stroke two-cylinder diesel engine conducted in framework of the European project dealing with the POWERtrain for Future Light-duty vehicles - POWERFUL. The main objective was to determine requirements on the air management including the engine intake and exhaust system, boosting devices and the EGR system and to select the best possible technical solution. With respect to the power target of 45 kW and scavenging demands of the two-cylinder two-stroke engine with a displacement of 0.73 l, a two-stage boosting architecture was required. Further, to allow engine scavenging at any operation, supercharger had to be integrated in the air loop. Various air loop system layouts and concepts were assessed based on the 1-D steady state simulation at full and part load with respect to the fuel consumption. Among the investigated boosting devices were the positive displacement and centrifugal superchargers driven from the crankshaft and placed upstream or downstream of the turbocharger with either the waste gate or variable turbine. Additionally, the electrically driven compressor as well as the electrically assisted turbocharger was assessed, too. Moreover, middle pressure and low pressure EGR loops were also compared. Due to the high boost pressure ratios above 5 and low mass flows, all boosting devices got at their limits or out of their working range even in the two-stage configuration. The best compromise regarding the feasibility, power target and fuel consumption was the configuration with the positive displacement supercharger placed downstream of the waste gate turbocharger. However, the biggest drawback of this solution was the necessity of sufficient air cooling between the stages due to the limitation of the maximum temperature at the outlet of the supercharger at 150°C. On the other hand, the boosting system with the supercharger upstream of the turbocharger required small compressor wheel to avoid surge and was ruled out due to the turbocharger procurement feasibility. Moreover, difficulties with EGR at the part load appeared at that configuration. If procurable for the whole engine mass flow range, the variable turbine geometry would provide better fulfillment of the power target and scavenging requirements than the waste gate turbine. The simulation showed no particular benefit of the variable drive of the supercharger in comparison with the dual drive gearbox due to the higher mechanical friction. Finally, the electric devices were put aside because of the unfeasible procurement and high demand on electric power of approx. 5 kW to achieve the power target.
Pohorelsky, Ludek, Brynych, Pavel, Macek, Jan, Vallaude, Pierre-Yves, Ricaud, Jean-Charles, Obernesser, Philippe, Tribotté, Pascal
Optimal Use of Boosting Configurations and Valve Strategies for High Load HCCI - A Modeling Study2012-01-11014/16/2012
This study investigates a novel approach towards boosted HCCI operation, which makes use of all engine system components in order to maximize overall efficiency. Four-cylinder boosted HCCI engines have been modeled employing valve strategies and turbomachines that enable high load operation with significant efficiency benefits. A commercially available engine simulation software, coupled to the University of Michigan HCCI combustion and heat transfer correlations, was used to model the HCCI engines with three different boosting configurations: turbocharging, variable geometry turbocharging and combined supercharging with turbocharging. The valve strategy features switching from low-lift Negative Valve Overlap (NVO) to high-lift Positive Valve Overlap (PVO) at medium loads. The new operating approach indicates that heating of the charge from external compression is more efficient than heating by residual gas retention strategies. Hot intake charge allows for valve events and combustion phasing that enable high turbine performance and alleviate the backpressure problems often associated with boosted HCCI. Reduced pumping work and high intake pressure allow for further improvements in the upper load limit and efficiency, while avoiding NOx formation and ringing. Boosting enables high load HCCI but combustion needs to occur in such a way as to allow for increased exhaust energy directed to the turbine. The addition of supercharging allows for higher intake pressures and temperatures, while the associated mechanical work penalty can be minimized by optimizing the supercharger gearing. The successful use of PVO and currently available turbochargers supports the realization of a dual mode SI/HCCI engine. This is also supported by the presence of high intake temperatures which allow compression ratio values closer to those of mainstream direct injection SI engines.
Mamalis, Sotirios, Babajimopoulos, Aristotelis, Guralp, Orgun, Najt, Paul
Ignition, Combustion and Exhaust Emission Characteristics of Micro-pilot Ignited Dual-fuel Engine Operated under PREMIER Combustion Mode2011-01-17648/30/2011
The objective of this study is to investigate the performance and emissions in a pilot-ignited supercharged dual-fuel engine, fueled with different types of gaseous fuels under various equivalence ratios. It is found that if certain operating conditions are maintained, conventional dual-fuel engine combustion mode can be transformed to the combustion mode with the two-stage heat release. This mode of combustion was called the PREMIER (PREmixed Mixture Ignition in the End-gas Region) combustion. During PREMIER combustion, initially, the combustion progresses as the premixed flame propagation and then, due to the mixture autoignition in the end-gas region, ahead of the propagating flame front, the transition occurs with the rapid increase in the heat release rate.
Azimov, Ulugbek, Tomita, Eiji, Kawahara, Nobuyuki
Second Generation Lysholm Compressor9807742/23/1998
The Lysholm compressors is developed and is produced as a high-efficiency supercharger optimum for use in automotive engines. This paper describes a second-generation Lysholm compressor that has a self-contained lubrication system and a low inertia, and describes the systems connecting the engine and the Lysholm compressor.
Takabe, Shigeru, Ikeya, Nobuyuki, Miyagi, Yoshiyuki
Potential of Additional Mechanical Supercharging for Commercial Vehicle Engines94226811/1/1994
Modern commercial vehicle engines are equipped with turbocharging and intercooling. This results in low emissions and fuel consumption. In the lower speed and load range and under transient conditions, these engines have disadvantages, as the fuel injection rate has to be limited to avoid excessive smoke emission. Also, the engine braking performance of highly charged, small displacement engines is also lower than that of large displacement engines. Mercedes-Benz decided to develop a combination of turbocharger and mechanical supercharger. In the lower speed range higher torque levels are possible and maximum torque is available without any lag especially in the transient mode with low smoke emission and fuel consumption. Vehicle performance during acceleration can be improved by up to 30%. During engine braking operation, the mechanical supercharger is activated throughout the whole engine speed range which results in a distinctive increase in braking power. Possible vehicle performance with and without additional Supercharging is discussed under fired and braking operation.
Schmitz, Thomas N., Holloh, Klaus-D., Juergens, Rolf, Fleckenstein, Guenter
An Analysis of Frictional Power=Loss for Developed New Vane-Type Super Charger Compressor8805642/1/1988
Recently, use of superchargers has been popularized as a means of improving output of passenger car engines. Supercharging is not a new problem. Gottlieb Daimler published an idea to supercharge a gasoline engine by a mechanically driven superchager in 1885 in DRP 34926 (Ref. 1)*. Two types of supercharging are used currently; turbo supercharging and mechanical supercharging. Turbo superchargers (exhaust gas turbine superchargers) are used in most case, however, have a weak point that the supercharging effect at a low speed is very small. For low speed operation, mechanical superchargers which can improve, this weak point greatly, are rather preferable to be used. However, they have several disadvantages, such as, with an increase in speed, power loss increases, delivery air temperature rises, delivery air density lowers, and so on. For automotive engine superchargers, it is necessary to overcome these problems.
Sakamaki, Hiroshi, Horikoshi, Yukio, Tanzawa, Kenji, Hirabayashi, Hiroshi
AS1915 Knob (Supercharger Control)AS1915-6 (Current)3/1/1987
No scope available.
Engine and Airframe Technical Standards Committee (TSC)
High Efficiency Supercharger Increases Engine Output, Reduces Fuel Consumption Through Computer Control86139210/1/1986
Efficiency of a supercharger mainly depends on the clearances between the rotors and the housing, but it has hitherto proved impossible to reduce the clearances without a strong possibility of seizure. A two lobe Roots type supercharger has been developed which overcomes this problem by means of a special resin coating on the rotors. As a result, an increase of 18% in volumetric efficiency of the supercharger is achieved. Engine torque is increased by 30%. Drive power loss resulting from the operation of a supercharger at partial load when boost was not required caused fuel consumption to increase by about 10%. An electro magnetic clutch and an air by-pass valve controlled by the onboard computer were used in the new supercharger to eliminate this fuel economy loss. A passenger car equipped with the new supercharged 2-liter engine demonstrated about the same acceleration performance as a 3-liter class car without sacrificing fuel economy.
Kato, Shinichi, Nakamura, Norihiko, Kato, Kichiro, Ohnaka, Hidemi
Comparison of a Supercharger vs. a Turbocharger in a Small Displacement Gasoline Engine Application8502442/1/1985
Supercharging and turbocharging can improve engine power and vehicle performance by boosting the intake manifold absolute pressure (MAP) above atmospheric pressure. This higher MAP results in increased charge densities which increase the maximum power available from the engine. A program to evaluate the overall system effects of supercharging and turbocharging has defined the differences and similarities between the two devices in a manner that supports the following conclusions.
Singer, David A.
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