Browse Topic: Diesel / compression ignition engines

Items (14,592)
Acoustic Assessment in a Small Displacement Diesel Engine2014-32-01291/30/2026
In the last years, the increasing concern for the environmental issues of IC engines has promoted the development of new strategies capable of reducing both pollutant emissions in atmosphere and noise radiation. Engines can produce different types of noise: 1) aerodynamic noise due to intake and exhaust systems and 2) surface radiated noise. Identification and analysis of noise sources are essential to evaluate the individual contribution (injection, combustion, piston slap, turbocharger, oil pump, valves) to the overall noise with the aim of selecting appropriate control strategies. Previous paper focused on the combustion related noise emission. The research activity aimed at diagnosing and controlling the combustion process via acoustic measurements. The optimal placement of the microphone was selected, where the signal was strongly correlated to the in-cylinder pressure development during the combustion process. Analysis and processing of the sound emission allowed the acoustic contribution of the combustion event to be isolated. Some indices capable of relating the combustion noise radiation back to the combustion development were defined. This paper presents an experimental activity devoted to analyze the entire noise generation process of a small displacement diesel engine. The purpose was to identify the contribution of the different sources (mechanical, combustion, fluid dynamic) to the overall emission. The methodology here proposed analyze the specific signature in the frequency domain of each source. The final objective was to use the microphone signal acquired in a proper selected location, to obtain indications about the effective strategies to achieve noise reduction. The repetitiveness of the measurements was guaranteed by a network encircling the engine. Microphones were placed in different positions and tests were performed in the complete engine operative field. In the paper, the experimental set-up is described, the methodology is presented. Results are then shown and discussed.
Chiatti, GiancarloRecco, ErasmoChiavola, OrnellaConforto, Silvia
Calculation of Airflow through the Air Cycle Technology’s Turboexpander and Its Effects on a Diesel Engine—Part I2025-01-50233/31/2025
Abstract Amidst escalating climate change, the sustainability of internal combustion engine (ICE) vehicles, particularly in heavy transport, remains a critical challenge. Despite emission reductions from 1990 to 2020, ICEs, particularly diesel engines in Europe, continue to pose environmental challenges, notably in nitrogen oxide (NOx) emissions. This study proposes a novel solution to address the problem of NOx emissions by incorporating Air Cycle Technology’s (ACT) turboexpander into diesel engines. Acting as a second-stage compressor, intercooler, and expander, the turboexpander aims to lower intake air temperature, thereby mitigating NOx formation. The study utilizes a 4.4-l JCB-TCA-74 turbocharged diesel engine retrofitted with the ACT turboexpander as the experimental platform. The methodology involves using empirical formulae to calculate the key parameters of engine airflow for a standard turbocharged diesel engine followed by repeating the calculations for the same engine fitted with a turboexpander. Parameters including intake temperature, cylinder temperature, exhaust gas temperature, and NOx emissions are analyzed in depth and compared for both the engines. Initial calculations suggest that the turboexpander has the potential to reduce intake temperatures by up to 34°C, resulting in significant reductions in NOx emissions. These findings underscore the promising role of turboexpanders in enhancing the sustainability of diesel engines, urging further exploration across various engine types. As emissions standards tighten, the adoption of innovative solutions like turboexpanders could contribute to a cleaner and more sustainable future for the ICE.
Fayaz, FarheenBrace, JordanAllport, JohnJavanbakht, Gina
Abstract The variability in fuel, particularly for fuel blends containing sustainable aviation fuels (SAFs), emphasizes the importance of understanding fuel properties for optimizing engine performance. This paper introduces spectroscopic fuel sensors capable of real-time estimation of jet fuel properties, mainly derived cetane number (DCN). While initially developed for unmanned aircraft systems (UAS), the paper explores their potential in ground vehicle applications: enhancing engine performance through sensing for feed-forward control and fuel property monitoring at fuel depots. The fuel sensing technologies are based on spectroscopic techniques coupled with machine learning (ML) approaches. The combination of these techniques demonstrates a promising solution for a wide spectrum of fuel applications.
Patel, Dev B.Sutar, AshishAbraham, AbhinavAmbre, DhananjayBrezinsky, KennethLynch, Patrick T.Okada, HarunaStafford, Jacob M.Miganakallu, NiranjanSanders, ScottRothamer, DavidMayhew, EricKim, Kenneth S.
Abstract We introduce novel approaches utilizing Physics Informed Machine Learning (PIML) for advanced diagnostics & prognostics of ground combat vehicles (CV). Specifically, we present the development of a PIML model designed to predict the health of engine oil in diesel engines. The condition of engine oil is closely linked to engine wear, thus serving as a crucial indicator of engine health. Our model integrates a physics-based simulation of engine wear in diesel engines, leveraging a time history of engine oil viscosity and engine speed as key input parameters. Furthermore, we conduct uncertainty quantification to assess the impact of varying parameters on engine oil health prediction. Additionally, our model demonstrates the capability to enhance low-fidelity physics models through the integration of a limited set of experimental data. By combining data-driven techniques with physics-based insights, our approach offers enhanced diagnostics and prognostics capabilities for ground combat vehicles, thereby facilitating proactive maintenance and optimization for operational readiness.
Betts, Juan F.Alizadeh, Arash
Abstract Biodiesel is a suitable alternative to diesel because of its carbon neutrality, renewability, lubricity, and lower pollutant emissions. However, extensive research indicates higher oxides of nitrogen (NOx) emissions with biodiesel. A practical method to combat this problem is utilizing water and biodiesel as emulsions. The effect of biodiesel-water emulsion in high-pressure fuel injection systems is not fully explored in the existing literature. The present study addresses this research gap by utilizing biodiesel-water emulsions in a modified light-duty diesel engine. The governor-controlled injection system was adapted to a fully flexible electronic system capable of high-pressure injection. Unlike other literature studies, the fuel injection timings were optimized with biodiesel-water emulsions to maximize brake thermal efficiency (bte) at every load condition. In a novel attempt, the biodiesel source, i.e., raw Karanja oil (RKO), a triglyceride, was utilized as the surfactant to stabilize the biodiesel-water emulsions containing 6%, 12%, and 18% water. The emulsions reduced the ignition delay and cylinder pressures, with less-intense premixed combustion and a more significant diffusion phase combustion than biodiesel. The emulsions also present a delayed combustion phasing following the injection timing trends. Among the tested emulsions, at 5.08 bar brake mean effective pressure (BMEP), 18% biodiesel-water emulsion resulted in an 18% reduced brake specific fuel consumption (bsfc), 5% increase in bte, 30% and 7% mitigation in NOx and smoke levels, with an increase of 10% and 28% for unburned hydrocarbon (HC) and carbon monoxide (CO) emissions.
Gowrishankar, SudarshanKrishnasamy, AnandAidhen, Indrapal Singh
Homogeneous charge compression ignition (HCCI) combustion is low-temperature combustion (LTC) mode that offers an alternative to conventional combustion modes. The advantages of HCCI combustion include high conversion efficiency and low NOx emissions. On the other hand, a direct control mechanism for combustion phasing control is not attainable as in conventional SI (spark ignition) or CI (compression ignition) engines. This limits the HCCI operational range and provides one of the biggest challenges in HCCI mode commercial implementation. High heat release rates and knock initiation limit the high load operation, whereas combustion instabilities limit the low load operation. In this context, this paper explores the use of water injection technique to control the combustion phasing and expand the load of an ethanol HCCI engine. The experiments were conducted on a three-cylinder diesel engine, where all the exhaust gases from a diesel cylinder were used to achieve the HCCI combustion in another cylinder. The results showed that the water injection technique was effective in controlling the charge reactivity and consequently the combustion phasing while enabling higher engine load. The water injection reduced combustion speed and heat release rates, which led to higher combustion duration, better combustion phasing control, and a reduction of ringing intensity. It was possible to expand the initial engine load from 2.0 bar without water injection to 6.0 bar IMEP with water injection. In addition, the ethanol HCCI combustion achieved high indicated efficiencies, ranging from 34 to 39%, while maintaining good combustion stability and low emissions characteristics.
Telli, Giovani D.Rocha, Luiz A.O.Zulian, Guilherme Y.Lanzanova, Thompson D.M.Martins, Mario E.S.
In recent years, the utilization of dual-fuel combustion has gained popularity in order to improve engine efficiency and emissions. With its high knock resistance, methane allows operation in high compression diesel engines with lower risk of knocking. With the use of diesel fuel as an ignition source, it is possible to exploit the advantages of lean combustion without facing problems to provide the high amount of ignition energy necessary to burn methane under such operating conditions. Another advantage is the variety of sources from which the primary fuel can be obtained. In addition to fossil sources, methane can also be produced from biomass or electrical energy.As the rate of substitution of diesel by methane increases, the trade-off between nitrogen oxide and soot is mitigated. However, emissions of carbon monoxide and unburned methane increase. Since carbon monoxide is toxic and methane has 25 times the global warming potential of carbon dioxide, these emission components pose a problem. Because of the stability of the molecule, methane catalysts require an exhaust gas temperature of over 500 °C in order to work effectively.In this work, the effect of conventional cooled external exhaust gas recirculation (EGR) and additional hot internal EGR are investigated for different substitution rates in a nonroad tractor engine converted to dual-fuel operation. The internal EGR rate is controlled by a variable second exhaust valve lift during the intake stroke - an approach which promises to benefit dual-fuel engines by increasing the in-cylinder gas temperature, thus favoring more complete combustion. A simulation model of the engine is used to determine the internal EGR rates and in-cylinder temperatures based on the experimental data. When internal EGR is used in combination with external EGR, the resulting emissions show additional reductions in nitrogen oxide (up to -51 %), carbon monoxide (up to -18 %) and methane (up to -28 %) with increasing internal EGR, while still maintaining low soot levels due to the substitution of diesel fuel for methane.
Mueller, FlorianGuenthner, MichaelWeigel, AlexanderThees, Matthias
To elucidate the complex characteristics of pre-chamber combustion engines, the interaction of the hot gas jets initiated by an active narrow throated pre-chamber with lean premixed CH4/air in a heavy-duty engine was studied computationally. A twelve-hole KAUST proprietary pre-chamber geometry was investigated using CONVERGE software. The KAUST pre-chamber has an upper conical part with the spark plug, and fuel injector, followed by a straight narrow region called the throat and nozzles connecting the chambers. The simulations were run for an entire cycle, starting at the previous cycle's exhaust valve opening (EVO). The SAGE combustion model was used with the chemistry modeled using a reduced methane oxidation mechanism based on GRI Mech 3.0, which was validated against in-house OH chemiluminescence data from the optical engine experiments. Two different piston geometries, a flat piston geometry, and a more realistic bowl piston geometry were studied to understand the influence of jet on main chamber combustion. Varying the piston geometries results in different free jet times and hence main chamber combustion characteristics. Pre-chamber fuel ratio (PCFR) 6% of the total amount of fuel was investigated while keeping the global excess air ratios (λ) condition a constant value of 2.0. Both piston cases resulted in similar pre-chamber pressurization, with almost the same pre-chamber discharge and the equal pressure difference between pre-and main-chamber (ΔP) at the start of jet ejection. Different combustion behaviors were observed on analysis of the heat release rate in the main chamber. The importance of turbulence generated by the pre-chamber-initiated jets was further studied. It was observed that free jet time is a critical factor in developing turbulence in the main chamber. This increase in turbulence helps in increasing the burning velocity causing faster combustion. The influence of the jet-piston interaction is also analyzed as that determines the combustion behavior in the later CAD.
Sanal, SangeethEcheverri Marquez, ManuelSilva, MickaelCenker, EmreIm, Hong G.
Regulations limiting GreenHouse Gases (GHG) from Heavy-Duty (HD) commercial vehicles in the United States (US) and European Union will phase in between the 2024 and 2030 model years. These mandates require efficiency improvements at both the engine and vehicle levels, with the most stringent reductions required in the heaviest vehicles used for long-haul applications. At the same time, a 90% reduction in oxides of nitrogen (NOx) will be required as part of new regulations from the California Air Resources Board. Any technologies applied to improve engine efficiency must therefore not come at the expense of increased NOx emissions. Research into advanced engine architectures and components has identified improved turbomachine efficiency as one of the largest potential contributors to engine efficiency improvement. However this comes at the cost of a reduced capability to drive high-pressure Exhaust Gas Recirculation (EGR). This study investigates the combination of a high-efficiency turbocharger and an electric EGR pump to allow improved engine fuel efficiency without the corresponding penalty to engine-out NOx. Results collected on a 13L 2019 model year engine on a dynamometer show the potential for a 3.5% reduction in engine Brake-Specific Fuel Consumption (BSFC) at engine operating conditions representative of highway cruise. Improvements at other engine operating conditions are also possible with careful matching of the turbocharger and EGR pump.
Johnson, GustavBockstanz, BradfordBagal, NileshHopkins, JustinHughes, DougPlayfoot, Ben
The present work proposes a viable approach to develop single-cylinder diesel engines for the future by implementing regulated intake air boosting (RIAB) and engine downspeeding (ED) along with the well-established low compression ratio (LCR) approach. The investigations were conducted in a mass-production light-duty single-cylinder diesel engine initially equipped with a naturally aspirated (NA) intake system. By lowering the compression ratio (CR) and implementing the intake air boosting (IAB) using a belt-driven supercharger, the maximum brake mean effective pressure (BMEP) of the engine could be increased by 50%. More importantly, the improved performance could be achieved without violating the peak firing pressure (PFP) limits. However, a significant penalty was observed in the brake-specific fuel consumption (BSFC) at low-load operating points due to the additional power consumption of the IAB system. Hence, RIAB was implemented to optimize the boost pressure with respect to engine load to simultaneously reduce the BSFC and oxides of nitrogen (NOx) and soot emissions. Further, the increased full-load performance of the engine was leveraged to implement the ED approach that could reduce the operating speeds of the engine by 37.8%. It was observed that the benefits of downspeeding a supercharged engine are significantly high due to the simultaneous reduction of the frictional losses of the base engine and the power consumption of the supercharger. Overall, by combining the above concepts and the proven LCR approach, significant benefits could be achieved in fuel economy and exhaust emissions that are quantified for the regulatory Modified Indian Drive Cycle (MIDC) using a one-dimensional tool. The obtained results show a net reduction of 77.8% and 39.5% in the soot and NOx emissions, respectively. Moreover, a significant benefit of 14.8% could be achieved in the fuel economy. Thus the proposed approach can be used to develop single-cylinder diesel engines for the future to improve vehicle performance and comply with stringent emission regulations.
Vikraman, V.Krishnasamy, AnandRamesh, A.
Knock is one of the main limitations on increasing spark-ignition (SI) engine efficiency. This has been known for at least 100 years, and it is still the case today. Knock occurs when conditions ahead of the flame front in an SI engine result in one or more autoignition events in the end gas. The autoignition reaction rate is typically much higher than that of the flame-front propagation. This may lead to the creation of pressure waves in the combustion chamber and, hence, an undesirable noise that gives knock its name. The resulting increased mechanical and thermal loading on engine components may eventually lead to engine failure. Reducing the compression ratio lowers end-gas temperatures and pressures, reducing end-gas reactivity and, hence, mitigating knock. However, this has a detrimental effect on engine efficiency. Automotive companies must significantly reduce their fleet carbon dioxide (CO2) values in the coming years to meet targets resulting from the 2015 Paris Agreement. One path towards meeting these is through partial or full electrification of the powertrain. However, the vast majority of automobiles in the near future will still feature a gasoline-fueled SI engine; hence, improvements in combustion engine efficiency remain fundamental. As knock has been a key limitation for so long, there is a huge amount of literature on the subject. A number of reviews on knock have already been published, including in recent years. These generally concentrate on current understanding and status. The present work, in contrast, aims to track the progress of research on knock from the 1920s right through to the present day. It is hoped that this can be a useful reference for new and existing researchers of the subject and give further weight to occasionally neglected historical activity, which can still provide important insights today.
Corrigan, Daire JamesFontanesi, Stefano
This SAE Recommended Practice establishes the test procedure, environment, and instrumentation for determining the maximum exterior sound level of highway motor trucks and truck tractors over 4540 kg gross vehicle weight rating (GVWR) with governed engines under stationary vehicle conditions. The basic procedure involves a full throttle engine acceleration and a closed throttle deceleration with the engine inertia as the load.
Light Vehicle Exterior Sound Level Standards Committee
This recommended practice is applicable to reciprocating engines powering unmanned aerial vehicles (UAV) having rated power values less than 22.4 kW, and which are not to be used for human transport.
E-39 Unmanned Aircraft Propulsion Committee
2.0.115 - Combustion Development of Multi-cylinder HSDI Common Rail Diesel engine to Meet Euro 4 Emission NormsSAE-PP-003563/3/2021
Direct injection diesel engine offers better Performance and fuel economy benefit over gasoline engine. Use of performance prediction software helps to reduce engine emission development time, effort and cost of development. In the present paper, 2.2 Liter, 4 cylinder diesel engine was upgraded for 25% higher power, 18% higher torque and emission from Euro3 to Euro4. Base engine performance prediction was done using AVL Boost software. This Model was validated by base engine performance test results. Boost model was used for parametric study to predict target engine performance. Vehicle simulation model was built with use of AVL Cruise software and run with a NEDC test cycle. 14 mode steady state speed-load points of engine were obtained with from NEDC cycle with time weightage factor. Engine hardware like turbocharger, injector, piston cavity, EGR cooler and pilot injection strategy were used for engine power and emission optimization on engine test bed. Design of experiments technique was used for emission optimization. INCA software was used for optimization of combustion parameters. Excel base program was developed for comparing engine out hot emissions to chassis dynamometer vehicle hot emissions. After correlation with hot emissions, vehicle was optimized for cold correction in base emission parameters. Three diesel oxidation catalytic convertors were tested and optimized for its precious metal loading on chassis dynamometer to meet Euro4 emissions. This process of emission development reduces considerable engine and vehicle emission development time.
Mutagaana, Festo
2.0.113.99 - *admin change pending* Comparison Study on Fuel Properties of Biodiesel from Jatropha, Palm and Petroleum Based Diesel FuelSAE-PP-003543/3/2021
The increase of air pollution and global warming is a threat for human life. Besides, the price of petroleum is increasing rapidly and the resources are diminishing. This obliged scientists and engineers to look for alternative sources of energy, which are cleaner and more sustainable. Biodiesel, defined as mono-alkyls of esters from vegetable oils and animals fat, is a cleaner renewable fuel and has been considered as the best alternative for petroleum based diesel fuel hence it can be used in any compression ignition engines without any significant modification. The main advantages of using biodiesel are its renewability and better quality of exhaust gas emissions due to their higher content of oxygen. The produce less soot and hence the feed stuck is plant it will regenerate the CO2 by the photosynthesis which ensures the renewability and reduces global warming. But these alternative fuels have faced some obstacles while utilizing in CI engines which are due to some of their physical and chemical characteristics. At this study the fuel properties of jatropha biodiesel and its blends (a non-edible feedstock) were compared with the properties of Palm biodiesel (an edible feedstock) and petroleum based diesel. The viscosity, density, oxidation stability, acid value, water content, iodine value, flash point, pour point, cloud point and calorific value of the samples were analyzed an discussed. The physical properties of the biodiesels are controlled by their chemical properties such as unsaturation level of fatty acids and oxidation stability. Results show that the viscosity of jatropha is higher than palm biodiesel although the density of palm biodiesel is higher. Oxidation stability of the biodiesel has impact on several chemical and physical properties and improvement of oxidation stability can make betterment in these properties. The results of this study will be used as a data backup for another research project.
Mutagaana, Festo
7.0.101 - A New Image De-hazing Method for Safety Critical ADAS ApplicationsSAE-PP-002772/4/2021
Driver safety and Advanced Driver Assistance Systems (ADAS) is gaining lot of importance these days. In some countries, there are strict regulations in place which mandate the use of certain ADAS features in automobiles. However, as the need for these safety critical systems increases, the challenges associated also increase. These challenges can arise due to technology, human factors or due to nature. In countries like India, where one can expect different weather conditions with changing geography, the associated challenges are mainly due to the natural factors like haze, fog, rain and smoke. This poses a challenging problem in terms of visibility for the drivers as well as in vision based ADAS; thereby, leading to many fatal road accidents. In this paper, a novel pre-processing technique, which addresses the interesting problem of enhancing the perceptual visibility of an image that is degraded by atmospheric haze, is proposed. The solution to this problem is presented by combining model (Beer Lambert model) based and non-model based technique of haze removal. The combined hybrid model picks the best haze free image from the series of non-hazy outputs, that are derived based on multiple scattering coefficients of the input hazy image. The idea here is to restore the true color of an image that is affected by the atmospheric haze. In comparison with the state of the art methods that are available in literature, the proposed method is shown to be capable of recovering better haze-free images both in terms of visual perception and quantitative evaluation. The proposed method promises better perceptual understandings and visibility restoration for vision based ADAS under hazy driving conditions.
Lname, Fname
6.0.116 - Development of 6 Years Old Child Virtual Model by Automatic ScalingSAE-PP-002712/4/2021
Traffic accidents cause one of the highest numbers of severe injuries in the whole population. The numbers of deaths or seriously injured citizens prove that traffic accidents and their consequences are still a serious problem to be solved. A lot of effort is devoted to both passive and active safety systems development. The transportation standards usually define safety requirements by regulations (e.g. ECE-R94, 96/79/EC and ECE-R95, 96/27/EC in Europe) with specific dummies for children to be used. The dummies include hardware sensors for monitoring accelerations, loads and other signals and each dummy is developed for a specific scenario, but there are limitations of these dummies, such as only a specific age or calibration just for a specific test. Taking into account that the consequence of a traffic accident is highly influenced by the stature of the body, virtual human body models, including those for children, start to play a significant role because they can be scaled or even personalized towards a particular population or even a particular person. The paper contributes to the field of vehicle safety technology concerning child restraint systems development, assessment and optimization with a virtual numerical approach. The goal of the paper is to exploit the previously developed scaling algorithm to create a virtual model of a six-year-old (6YO) child and to compare its response to the virtual dummy used for child safety in order to propose an automatic scaling process for a population-based vehicle safety assessment. The automatic scaling algorithm developing virtual human body models for a given age and gender is used to create the virtual 6YO child model. The algorithm scales body dimensions and particular segments' mass and the flexibility of the body is driven by flexindex and stiffness scaling. The performance of the automatically developed virtual 6YO child model was tested in frontal and lateral directions. The frontal response was tested with a standard sled test simulation using the standardized AAMA pulse in the frontal direction. The lateral response was tested with a side barrier impact test. The results of both tests were compared to the validated virtual Q6 Child Dummy FE model. The paper shows good performance of the automatic scaling process for developing 6YO virtual model for safety assessment. The automatically developed 6YO child model corresponds well from both the anthropological point of view and performance point of view to the existing validated dummy model.
Mutagaana, Festo
6.0.109 - Comparison Study on Fuel Properties of Biodiesel from Jatropha, Palm and Petroleum Based Diesel FuelSAE-PP-002652/4/2021
The increase of air pollution and global warming is a threat for human life. Besides, the price of petroleum is increasing rapidly and the resources are diminishing. This obliged scientists and engineers to look for alternative sources of energy, which are cleaner and more sustainable. Biodiesel, defined as mono-alkyls of esters from vegetable oils and animals fat, is a cleaner renewable fuel and has been considered as the best alternative for petroleum based diesel fuel hence it can be used in any compression ignition engines without any significant modification. The main advantages of using biodiesel are its renewability and better quality of exhaust gas emissions due to their higher content of oxygen. The produce less soot and hence the feed stuck is plant it will regenerate the CO2 by the photosynthesis which ensures the renewability and reduces global warming. But these alternative fuels have faced some obstacles while utilizing in CI engines which are due to some of their physical and chemical characteristics. At this study the fuel properties of jatropha biodiesel and its blends (a non-edible feedstock) were compared with the properties of Palm biodiesel (an edible feedstock) and petroleum based diesel. The viscosity, density, oxidation stability, acid value, water content, iodine value, flash point, pour point, cloud point and calorific value of the samples were analyzed an discussed. The physical properties of the biodiesels are controlled by their chemical properties such as unsaturation level of fatty acids and oxidation stability. Results show that the viscosity of jatropha is higher than palm biodiesel although the density of palm biodiesel is higher. Oxidation stability of the biodiesel has impact on several chemical and physical properties and improvement of oxidation stability can make betterment in these properties. The results of this study will be used as a data backup for another research project.
Mutagaana, Festo
6.0.107 - A Unified Approach for Prediction and Control of Motorcycle Vibration Subjected to Engine Dynamic ForceSAE-PP-002632/4/2021
In this paper the approach to predict vibrations in motorcycles is presented. It can be divided mainly in two parts: prediction of engine forces using multi body dynamics (MBD) simulation and prediction of vibration response using FEA. Dynamic forces predicted at each engine mount through MBD simulation are used as input to FE analysis for vibration prediction. Single cylinder SI engine having primary balancer shaft is considered to develop this methodology. Flexibilities of important parts are considered for MBD simulation. Crankshaft ball bearing which is used in almost all two wheeler engine is modeled with 6×6 stiffness matrix. It provides coupling between radial, axial and tilting deflections of bearing and it also allows moment transfer from crankshaft to casing. This helps to predict realistic forces at each bearing and engine mounts. Distribution of primary and secondary forces at crank bearings and at different engine mounts is studied. Forces predicted from MBD simulation at each engine mounts are applied to full vehicle FE model. Forced response is predicted at each TSP and compared with test response at same point. It was found that predicted response was in well agreement with test response. Based on understanding of distribution of forces it is decided to increase mount stiffness of the support experiencing more force. This in turn helped to reduce vibration at TSP. This approach is effective to predict vibrations in early design stage to reduce development cost and time.
Mutagaana, Festo
Near-TDC flow field analysis in a high-tumble production SI engine using endoscopic high-speed Particle Image Velocimetry (eHS-PIV)SAE-PP-002512/3/2021
The latest generation spark-ignition (SI) engines implement high tumble flow design to achieve unprecedented high brake thermal efficiency of over 40%, which will continue to play an important role in both conventional and electrified future vehicles. To maximise the potential of high-tumble SI engines, there is a clear need for in-cylinder flow and flame analysis conducted timely in a realistic environment. For the first time, this study meets this need by performing innovative endoscopic imaging of flow fields and flame inside the cylinder of a selected production engine using a particle image velocimetry (PIV) laser and high-speed camera system operated at 35 kHz. Through this timeresolved, two-dimensional measurement of the realistic in-cylinder phenomenon, many new findings have been achieved. Regarding the tumble vortex, its centre is seen more shifted to the exhaust valve side, which is related to an asymmetric, “surging” flow structure formed during the upward motion of the piston in the compression stroke. When the piston approaches towards the top dead centre, the tumble centre is not clearly defined anymore, but a new lateral exhaust-to-intake flow forms as the surging flow bounces back off the exhaust valve side of the pent-roof. This wallguided “bounce-back” flow does not form when the intake valve closure is retarded for the realisation of Atkinson Cycle and thus the surging flow is reduced and peaks at later timing. The new in-cylinder flow structures observed from the high-tumble engine directly impact the flame development. From the high-speed natural combustion luminosity imaging performed using the same camera endoscope, the flame centroid is found to shift towards the intake valve side, which is consistent with the bounce-back flow direction at the advanced intake valve closure timing.
Anthony, Lindsay
6.0.113 - Measuring Smoke Emissions from Different Generations Diesel Passenger Cars in Antwerp-Belgium During Winter and SpringSAE-PP-002442/3/2021
More than 600 passenger cars were measured during winter and spring at the end of 2012 beginning 2013 in Antwerp Belgium in order to determine the effect of mileage and year of first registration on smoke emissions or smoke opacity from diesel light duty vehicles. All measurements were contacted in two different campuses of the University of Antwerp and under different ambient conditions. Various parameters such as ambient temperature, ambient humidity, car age, number of passengers in each cars, time of measurement etc. were taken into account and presented in this paper. All findings from these set of measurements were split into two big categories, those cars with less than 150,000km on the clock and the second one with those cars with higher number of mileage. The effect of ambient temperature but also the mileage on smoke opacity will be presented and discussed in more details. Smoke emissions are dependent also on ambient humidity and in this study will be considered the important role that humidity plays in total smoke opacity from various diesel engines. Finally the effect of mileage on smoke opacity is something that will be also examined and discussed intensively. Last but not least, a comparison between two similar cars equipped with the same engine in terms of capacity but fitted with standard and tuned electronic control unit (ECU) respectively was done and interesting findings will be shown in this work.
Mutagaana, Festo
Knock detection method for dual-fuel compression ignition engines based on block vibration analysisSAE-PP-002372/3/2021
A new knock detection method based on block vibration analysis, specially developed for dual-fuel compression ignition engines, is presented in this work. Experimental tests were carried out in a four-cylinder compression ignition engine at full and 60% of load, running at 2000, 2500, and 3200 rpm with different amounts of hydrogen and liquefied petroleum gas injected in the air inlet hose. Fuel flow was increased in approximately 10% energy share steps until knock was detected for both fuels. The maximum substitutions at full and 60% of load were 38%, 54% for hydrogen, and 57%, 63% for liquefied petroleum gas, respectively. The component of the block vibration signal that is sensitive to knock was determined by studying the block's resonant frequency, the influence of valve closing impacts, and comparing the block vibration recorded with knocking and non-knocking combustion. To quantify the knock intensity of a combustion cycle, four fast-computing metrics were tested selecting the maximum amplitude of filtered vibration for knock detection since it was the least sensitive to crankshaft speed. Two knock indexes for knock evaluation were compared, concluding that the pondered deviation from the reference index, proposed in this work, has a better performance. The knock threshold was achieved when the knock index was greater than 5 regardless of the substitute fuel, crankshaft speed, and engine load. Finally, the method was optimized for real-time knock detection.
Anthony, Lindsay
The Effect of Engine Speed, Exhaust Gas Recirculation (EGR) and Compression Ratio on Isobaric CombustionSAE-PP-002322/3/2021
The present study evaluates the effect of engine speed, exhaust gas recirculation (EGR) and compression ratio on conventional diesel combustion (CDC) and two isobaric combustion cases, by utilizing multiple injection strategies. The experiments were conducted in a Volvo D13C500 singlecylinder, heavy-duty engine, fuelled with standard EU diesel fuel. The engine was operated at three different speed of 1200, 1500 and 1800 revolutions per minute (rpm). For each engine speed and combustion cases, EGR rate was varied from 0 ~ 40%. The low-pressure isobaric combustion (IsoL) and high-pressure isobaric combustion (IsoH) were maintained at peak cylinder pressure (PCP) of 50 and 68 bar, respectively, which was representative of the peak motoring pressure (PMP) and PCP of conventional diesel combustion. This was possible by adjusting the intake air pressure to 1.7 bar and 2.3 bar – absolute for IsoL and IsoH, respectively at 1200 rpm. At higher engine speed, the intake air pressure was further increased to maintain top-dead center (TDC) pressure. Irrespective of engine speed and EGR rates, it was found that IsoH has similar or higher gross indicated efficiency than CDC with the lowest efficiency for IsoL combustion. The heat transfer losses were lower while the exhaust losses were higher for isobaric cases, compared to CDC. The heat transfer losses were further reduced due to limited time availability at higher engine speed with a penalty in higher exhaust losses for all combustion cases. This additional exhaust energy would not be totally lost as it can be converted into useful work using expander cylinder of the double compression expansion engine (DCEE) concept. At given engine speed, higher EGR rates resulted in higher carbon monoxide (CO)/unburnt hydrocarbon (UHC)/soot emissions with lower nitrogen oxides (NOx) emissions. However, with increased engine speed, CO and UHC emissions were highly unchanged. A typical soot-NOx trade-off characteristic can be seen with increased soot and reduced NOx emissions, largely due to reduced charge premixing time at higher engine speed. From the compression ratio comparison results, it was found that a lower compression ratio resulted in reduced gross indicated efficiency and increased exhaust losses. Compared to the higher compression ratio, the lower compression ratio also led to lower heat transfer losses due to reduced combustion temperature. Besides, the NOx emissions were reduced with increased soot concentration at the lower compression ratio.
Anthony, Lindsay
2.0.101 - Experimental Study of cooling of Continuously Variable Transmission (CVT) in ScooterSAE-PP-002102/1/2021
The continuously variable transmission (CVT), which was conceptualized more than 500 years ago, is just now beginning to replace traditional transmissions in some automobiles. It is mostly used in scooter transmission. Engine power is transmitted to wheel through belt drive between two pulleys. The diameter of belt contact with pulley can change continuously and hence provide infinite gear ratios between driver and driven shafts. This technology leads to a smoother ride of vehicle. Heat is generated inside CVT due to friction between drive belt and clutch pulley. Amount of heat generated is even more due to clutch slippage during acceleration and deceleration. This will affect the service life of CVT components such as front movable drive (FMD), clutch pulley, clutch outer, and belt. In scooters generally, air cooling is preferred over liquid cooling. Cooling is achieved by incorporating centrifugal fan inside CVT housing. For better durability/service life, the degree of heat generated at CVT components should be minimal. The objective of this work is to identify the parameters causing change in temperature of CVT components and to evaluate its surface temperature in accordance with changed parameters. With reference to this, experiments were conducted with requisite design modification inside CVT housing, which enhances cooling effect. Amongst, variables determining air flow rate, are studied and their effect on temperature inside CVT housing is observed experimentally. Keeping the previous variables unaltered, further design modifications related to air flow pattern are done and cumulative effect of all variables is observed. Experiments were performed on an 110cc scooter engine by following customer driving pattern on chassis dynamometer. Results showed that design modifications intended for better cooling effect, has brought down temperature at CVT components. So, desired cooling effect is observed inside CVT housing imparting better service life of CVT components.
Mutagaana, Festo
058 - Steering Effort Reduction by DC Motor Assisted Steering Mechanism in 3- Wheeler VehicleSAE-PP-001961/30/2021
The steering system of a 3-wheeler vehicle comprises a single column steering tube. The steering inclination at handle bar end is converted to wheel slip or inclination by the steering column. A compromise in either ride or handling is considered in the functional requirement of the 3-wheeler vehicle. The 3- wheeler vehicle under study is designed for ride comfort and the handling levels are compromised. Variants of the vehicle under study are meant for public passenger transport requirements. Drivers' ride comfort is considered as the primary functional requirement during design and driver's steering fatigue is not given importance. For the comfort of driver, steering effort has to be less without compromise in handling characteristics. The driver of this type of vehicle drives the vehicle for 15-18 hours a day. Driver's feedback suggests high steering effort as a human fatigue failure mode and also a cause of shoulder pain. In the present work, a DC motor assisted steering mechanism with an electronic control module has been designed. This improves the handling of the vehicle and reduces the static steering effort. Steering effort of the vehicle is experimentally determined in a test track for static maneuvering conditions. A look up table reference is used for programming the control module and to control the DC motor for various operating steering angle. The tests are also carried out in driver alone and gross vehicle weight conditions. The test results suggest reduce of steering effort levels for the vehicle studied.
Mutagaana, Festo
053 - System Optimization for a 2-Stroke Diesel Engine with a Turbo Super Configuration Supporting Fuel Economy Improvement of Next Generation EnginesSAE-PP-001911/30/2021
The objective of this paper is to present the results of the GT Power calibration with engine test results of the air loop system technology down selection described in the SAE Paper No. 2012-01-0831. Two specific boosting systems were identified as the preferred path forward: (1) Super-turbo with two speed Roots type supercharger, (2) Super-turbo with centrifugal mechanical compressor and CVT transmission both downstream a Fixed Geometry Turbine. The initial performance validation of the boosting hardware in the gas stand and the calibration of the GT Power model developed is described. The calibration leverages data coming from the tests on a 2 cylinder 2-stroke 0.73L diesel engine. The initial flow bench results suggested the need for a revision of the turbo matching due to the big gap in performance between predicted maps and real data. This activity was performed using Honeywell turbocharger solutions spacing from fixed geometry waste gate to variable nozzle turbo (VNT). New simulations results recommend VNT as it offers a higher potential to reduce BSFC with increase power and low end torque output than the original matching. For the high pressure stage the mechanical Roots type and the CVT superchargers have been assessed and the latter one has been identified having higher power adsorption than traditional positive displacement supercharger. This has allowed the supplier to work on an optimization of the units. Ultimately the VNT with CVT supercharger has been assessed on engine and it allowed confirming the validity and accuracy of the GT Power model after its calibration.
Mutagaana, Festo
022 - Single Cylinder Diesel Engine Mount Configuration for Reduced Vibration in a Three-Wheeled VehicleSAE-PP-001511/25/2021
The diesel power train (engine and transmission) is the most significant mass contributor in a three- wheeled vehicle. High idling vibrations from the engine get transmitted to the structure and the body panels through the engine mounts. Isolation of these vibrations by proper design of rubber mounts is the most effective engineering approach to improve ride quality of vehicle. In the present study, a mathematical model of the powertrain and mount system is developed; with the engine and transmission being assumed to behave as a rigid body (6 degrees-of-freedom) and the compliance comes from the mounts. As a first step, the modes and natural frequencies are obtained. Following this the response to unbalanced inertial forces for an excitation frequency range of 20-60 Hz (1200-3600 rpm) has been obtained. The model is validated by comparing its results with results of previous published research work. Also, motoring experiments are conducted on a baseline configuration to obtain the vibration response at mounts and mode shapes through ODS (Operational Deflection Shape) for validating the math model. A detailed parametric study is conducted and a new combination of mount system design variables were arrived as proposed solution which in comparison with baseline configuration showed that the vibration response reduces by 40% at idling and 60% in the engine operating range. Experiments conducted on the improved design show similar improvement. Thus, using this validated analytical math model, a closer-to-optimal design can be obtained with minimal dependency on iterative experimental methods which are costlier and time consuming.
Mutagaana, Festo
This Aerospace Information Report (AIR) describes the use of FTIR analyzers for measurements of gaseous emissions from aircraft gas turbine engines and combustion rigs. The use of FTIR analyzers can be demonstrated as a suitable and cost-effective equivalent to NDIR and chemiluminescence analyzers as prescribed in ARP1256 for the measurement of CO, CO2, NO, and NO2, where NOx is closely approximated by the sum of NO and NO2 concentrations. FTIR analyzers may be proven suitable for equivalency of analyzers used in current emission testing. Additionally, FTIR analyzers have potential for equivalent measurements of “total” hydrocarbon (THC) as currently defined in ARP1256.
E-31G Gaseous Committee
This SAE Recommended Practice establishes equipment and procedures for the evaluation of the effectiveness and other performance characteristics of spark arresters or turbochargers used on the exhaust system of large engines normally used in a railroad locomotive, stationary power plant, and other similar applications. This document does not cover applications requiring flame arresting, exhaust gas cooling, or isolation from explosive gases. Two test methods are presented: a laboratory test using ambient air (cold test) and an engine test using exhaust gases (hot test). The hot test is preferred. Arresters tested by the provisions of this document can be expected to perform as tested when tilted no more than 45 degrees from their normal position. Test results from a spark arrester or turbocharger evaluated by the hot test can be applied to different engines of similar design, provided the data shows it to be effective in the applicable flow ranges. Certain design and performance characteristics, which represent current requirements by regulatory agencies for qualification and approval under this document, are listed in Appendix A.
SAE IC Powertrain Steering Committee
This SAE Aerospace Information Report (AIR) is intended as a source of comparative information and is subject to change to keep pace with experience and technical advances. This document describes currently used fuels and fuels which may be used in the future. Conventional gasoline and diesel fuels are intentionally omitted from this document.
AGE-3 Aircraft Ground Support Equipment Committee
With highway vehicles using over 20% of the total energy consumption in the United States, making strides in improving their fuel economy will positively influence the nation’s environmental impact. One methodology to accomplish this outcome is by reducing vehicle weight. In this regard, since the internal combustion (IC) engine is a major contributor to the mass of an automobile, it is an ideal area to target. Prior efforts in this area include using alternative materials (e.g., aluminum or magnesium) to decrease weight. Here, additive manufacturing (AM) is an appealing option due to its freedom from typical manufacturing constraints and the ability to produce highly optimized designs using nonconventional powertrain materials (e.g., titanium). The use of AM has the potential to increase reliability, improve performance, decrease production cost, and possibly minimize the number of parts. Since metal-based AM is a relatively new area of manufacturing for IC engines, its use has been largely limited to research, motorsport, and luxury vehicle activities. Given its potential, this effort provides a review and summary of AM work completed in this field including design optimization, prototyping, tooling and indirect manufacturing, part production, and remanufacturing and repair for IC engine components.
Gray, JameeDepcik, Christopher
The present study evaluates the effect of engine speed, exhaust gas recirculation (EGR), and compression ratio on conventional diesel combustion (CDC) and two isobaric combustion cases, by utilizing multiple injection strategies. The experiments were conducted in a Volvo D13C500 single-cylinder, heavy-duty engine, fuelled with standard European Union (EU) diesel fuel. The engine was operated at three different speeds of 1200, 1500, and 1800 revolutions per minute (rpm). For each engine speed and combustion cases, the EGR rate was varied from 0% to 40%. The low-pressure isobaric combustion (IsoL) and high-pressure isobaric combustion (IsoH) were maintained at peak cylinder pressure (PCP) of 50 and 68 bar, respectively, which was representative of the peak motoring pressure (PMP) and PCP of CDC. This was possible by adjusting the intake air pressure to 1.7 and 2.3 bar—absolute for IsoL and IsoH, respectively, at 1200 rpm. At a higher engine speed, the intake air pressure was further increased to maintain top dead center (TDC) pressure. Irrespective of engine speed and EGR rates, it was found that IsoH has similar or higher gross indicated efficiency than CDC with the lowest efficiency for IsoL. The heat transfer losses were lower while the exhaust losses were higher for isobaric cases, compared to CDC. The heat transfer losses were further reduced due to limited time availability at higher engine speeds with a penalty in higher exhaust losses for all combustion cases. This additional exhaust energy would not be totally lost as it can be converted into useful work using an expander cylinder of the double compression expansion engine (DCEE) concept. At a given engine speed, higher EGR rates resulted in higher carbon monoxide (CO)/unburnt hydrocarbon (UHC)/soot emissions with lower nitrogen oxides (NOx) emissions. However, with increased engine speed, CO and UHC emissions were highly unchanged. A typical soot-NOx trade-off characteristic can be seen with increased soot and reduced NOx emissions, largely due to reduced charge premixing time at higher engine speed. From the compression ratio comparison results, it was found that a lower compression ratio resulted in reduced gross indicated efficiency and increased exhaust losses. Compared to the higher compression ratio, the lower compression ratio also led to lower heat transfer losses due to reduced combustion temperature. Besides, the NOx emissions were reduced with increased soot concentration at the lower compression ratio.
Goyal, HarshDyuisenakhmetov, AibolatHouidi, Moez BenJohansson, BengtBadra, JihadCenker, EmreChang, Junseok
This SAE Standard outlines the engine oil performance categories and classifications developed through the efforts of the Alliance of Automobile Manufacturers (Alliance), American Petroleum Institute (API), the American Society for Testing and Materials (ASTM), the Engine Manufacturers Association (EMA), the International Lubricant Specification Advisory Committee (ILSAC), and SAE. The verbal descriptions by API and ASTM, along with prescribed test methods and limits, are shown for active categories in Table 1 and obsolete categories in Table A1. Appendix A is thus a historical documentation of the obsolete categories. For purposes of this document, active categories are defined as those (a) for which the required test equipment and test support materials, including reference engine oils and reference fuels, are readily available, or for which the Category Life Oversight Group has established equivalencies between unavailable tests and newer, available tests; (b) which ASTM or the test developer monitors precision for all tests; and (c) which are available for licensing by API EOLCS at time of writing. The current processes for initiating new classifications were developed through the cooperative efforts of the Alliance, API, ASTM, EMA, ILSAC, and SAE. New ILSAC classifications are developed using the procedure defined in API 1509 Annex C. New API “C” categories are added using the procedure defined in API 1509 Annex D. New API “S” categories are added by the API Lubricants Group.
Fuels and Lubricants TC 1 Engine Lubrication
This SAE Recommended Practice is applicable to gasoline and diesel fuel filters installed on fuel dispensing equipment, mobile or stationary. It describes a set of tests used to characterize the structural integrity, filtration performance, and reaction to water contaminant with fuel dispensing filters.
Filter Test Methods Standards Committee
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