Browse Topic: Crankcases

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Enhancements in Hydrogen Low Pressure Injection on Small Two-Stroke Engines2024-32-004704/18/2025
The use of small 2-stroke crankcase scavenged engines running on hydrogen is very attractive for low power rates, when low cost and compact dimensions are the fundamental design constraints. However, achieving optimal performance with hydrogen fuel presents challenges, including uneven air-fuel mixtures, fuel losses, and crankcase backfiring. This research focuses on a small 50cc 2-stroke loop-scavenged engine equipped with a patented Low-Pressure Direct Injection (LPDI) system, modified for hydrogen use. Experimental results demonstrate performance comparable to the gasoline counterpart, but further optimizations are needed. Consequently, CFD-3D simulations are employed to analyses the injection process and guide engine development. The numerical analysis focuses on a fixed operating condition: 6000 rpm, Wide Open Throttle (WOT), with a slightly lean mixture and injection pressure fixed at 5 bar. A numerical model of the entire engine is set up with the primary objective of improving
Caprioli, Stefano, Schoegl, Oliver, Oswald, Roland, Kirchberger, Roland, Mattarelli, Enrico, Rinaldini, Carlo Alberto
Technical Paper
Development of 8L Hydrogen IC Engine2024-26-017001/16/2024
Throughout the world the efforts are being carried out to reduce the GHG emissions from transportation sector. As Volvo Group is a signatory of SBTi and having internal target of Carbon neutrality by 2040, we have intensified & also diversified our R&D efforts to develop powertrains of the future having mix of conventional, various alternate fuels, electric etc. There will not be a unique solution or strategy suiting for all the markets in the world. Each market will have its own motivation & factors which OEMs need to consider while deciding the short term, midterm & long-term strategy for powertrain technology. Accordingly, OEMs must be ready with product mix suitable for all global markets. This paper will talk about the efforts taken and lessons learned during development of Hydrogen fueled IC Engine. We used 8L Diesel IC engine as a base to convert it to Hydrogen powered IC engine, in a retrofit spirit, so that with minimum changes we could make the working prototype. This engine
LAD, MAKRAND RAJENDRA, Neveu, Jean Marc, S, ANOOP KRISHNA
Technical Paper
OIL AEROSOL EMISSION OPTIMISAITON IN HIGH POWER DIESEL ENGINE USING DEFLECTORS IN TURBO CHARGER OIL DRAIN CIRCUIT2024-26-004701/16/2024
Closed crankcase ventilation prevent harmful gases from entering atmosphere thereby reducing hydrocarbon emissions. Ventilation system carries blowby gases leaking through combustion process along with oil mist to Engine intake system. Major sources of blowby often occurs from leak in combustion chamber through piston rings, leaks from turbo shafts & valve guides. Oil mist carried away by blowby gases gets separated using filtration media. Fleece type separation media has high separation efficiency for particles above 10 microns. Efficiency drops if mist particle is below 10-micron size. Low size aerosol mist generally forms due to flash boiling on piston under crown area and on shafts of turbo charger due to high speeds combined with elevated oil temperatures. High power density diesel engine is taken for our study. It produces low particle size oil mist which contributes to aerosol emission of 3 gm/hr when operated at rated speed. Particle size measurement done using light refraction
M, Velshankar, Dharan R, Bharani, DHADSE, ASHISH, Permude, Ashok, Loganathan, Sekar
Technical Paper
A mechanism to maintain negative crankcase pressure in a turbocharged gas engine to meet Euro-VI emission regulation and to reduce oil consumption.2024-26-014501/16/2024
Emissions regulation continually drives the automotive industry to innovate and develop. This pushes to introduce mechanism to maintain negative crankcase pressure in gas engine to meet this changing regulation. The way a turbocharger is used, to meet engine performance, can impact the pressure balance over the compressor and turbine end seals. This pressure difference can allow oil to leak through turbocharger seals. In normal engine operating condition, the pressure in the turbocharger end housings is higher than the bearing housing and oil/gas flows into the bearing housing, through the oil drain to the crankcase. Under certain operating conditions, such as low idle and thermal management, this pressure difference can be reversed with a higher bearing housing pressure than the pressure behind the turbine compressor wheel. Under this condition oil/gas will flow out of the bearing housing to the recess behind the compressor wheel. The bearing housing pressure will always track the
R, MAHESH BHARATHI
Technical Paper
Multi-Dimensional CFD Studies of Oil Drawdown in an I4 Engine2022-01-047303/29/2022
A computational study based on unsteady Reynolds Averaged Navier Stokes that resolves the gas-liquid interface was performed to examine the unsteady multiphase flow in a 4 cylinder Inline (I-4) engine. In this study, the rotating motion of the crankshaft and reciprocating motion of the pistons were accounted for to accurately predict the oil distribution in various parts of the engine. Three rotational speeds of the crankshaft have been examined: 1000, 2800, and 4000 RPM. Of particular interest is to examine the mechanisms governing the process of oil drawdown from the engine head into the case. The oil distributions in other parts of the engine have also been investigated to understand the overall crankcase breathing process. Results obtained show the drawdown of oil from the head into the case to be strongly dependent on the venting strategy for the foul air going out of the engine through the PCV system. Results also show the dynamic holdup of oil in the steady operation to be
Pandey, Ashutosh, Schlautman, Jeff, Nichani, Varun
Technical Paper
Design Challenges & Solution in Modifying Compact 4-Stroke Diesel Engine while Adapting D-Cycle Technology2022-01-072503/29/2022
This paper reviews application of 2-Stroke D-Cycle (i.e. Differential Stroke) technology to compact tractor 4-Stroke 2.7L 4-Cylinder CRS (Common Rail System) Naturally aspirated (NA) Diesel engine for improving efficiency & power. The study considers design challenges that are presented for accommodating D-cycle technology in engine. The paper also covers resolving those challenges with established technical solutions. Study focuses on modifying conventional compact 4-stroke diesel engine with the intention of keeping design changes minimal for incorporating differential stroke technology. Designing of vertically splitting lightweight piston crown which can smoothly engaged and separated from main piston body without any impact, stem rod which connects piston crown with rocker arm, hollow connecting rod and rocker arm which is actuated by additional camshaft in addition to present camshaft. Lubrication of additional camshaft is done by extending existing oil galleries. Gear train
Telshinge, Pravin, Paulraj, Lemuel
Technical Paper
Laser Interferometry to Investigate the Strain and Stress State of Details and Units of Heat Engines03-15-04-002310/08/2021
The article is devoted to laser interferometry technology for investigating the strain and stress state (SSS) of heat engine details and units. It is an efficient alternative to traditional technologies based on using strain gauges. It has been shown that the use of traditional technologies to experimentally investigate the SSS of heat engine complex details when using the strain gauges requires a significant amount of research and time. Thus, deploying physical effects previously not used for solving similar problems is a perspective research direction that includes laser interferometry technology. The article deals with its use to experimentally investigate the SSS of complex details, such as a crankcase block of an internal combustion engine (ICE). Laser interferometry research is based on the use of holographic interferometry, speckle photography, electronic speckle pattern interferometry, and modern methods of computer simulation. The article goes on to say that to achieve the aim
Kesariiskyi, Oleksandr G., Marchenko, Andrii, Gritsuk, Igor, Mateichyk, Vasyl, Pylyov, Volodymyr, Kravchenko, Serhii
Journal Article
Effect of CCV and OCV system in Heavy Duty CNG Engine on the Particulate Emissions2021-26-011609/22/2021
Due to increasing pollution and climatic cries, newly implemented BS VI emission norms in India have stressed on the reduction of emission. For which many automobiles have been shifted to alternate fuels like CNG. Also, Indian Automotive market is fuel economy cautious. This challenges to focus on improving fuel economy but without increase in emissions. Crankcase blowby gases can be an important source of particulate emission as well as other regulated and unregulated emission. They can also contribute to the loss of lubricating oil and to fouling of surface and engine components. Closed Crankcase Ventilation (CCV) or Open Crankcase Ventilation (OCV) is capable to reduce the particulate emissions by removing the oil mist that caused mainly due to blowby in combustion chamber. This paper work is focused, to measure the effect of the CCV and OCV systems on the engine out emissions, primarily on the particulate emissions. A comparative analysis of these crankcase ventilation systems is
Sutar, Prasanna S, bandyopadhyay, Debjyoti, Sonawane, Shailesh Balkrishna, Rairikar, S D, Kavathekar, Kishorkumar, Thipse, Sukrut S, Kale, Samir, Kshirsagar, Chinmay
Journal Article
A Study on the Function of Oil Drain Holes in the Oil Ring Groove of a Piston and Their Effect on Oil Consumption2019-01-236012/19/2019
Clarifying the mechanism of oil transporting upward at around an oil ring of a piston is necessary for calculating engine oil consumption. This study aimed to clarify the function of oil drain holes in the oil ring groove of a piston. The effect of the oil drain holes in the groove on oil consumption was investigated. Also the pressure balance around the oil ring was measured. It was found that the drain holes in the groove lowered oil consumption. It was assumed that lower pressure in the groove with the drain holes caused less oil flow into the third land.
Miura, Ken, Ohashi, Takaki, Hasegawa, Hiroki, Ito, Akemi, Nishibe, Koichi
Technical Paper
The Rotating Liner Engine (RLE) Diesel Prototype: Preliminary Testing2019-01-008401/15/2019
The Rotating Liner Engine (RLE) concept is a design concept for internal combustion engines, where the cylinder liner rotates at a surface speed of 2-4 m/s in order to assist piston ring lubrication. Specifically, we have evidence from prior art and from our own research that the above rotation has the potential of eliminating the metal-to-metal contact/boundary friction that exists close to the piston reversal areas. This frictional source becomes a significant energy loss, especially in the compression/expansion part of the cycle, when the gas pressure that loads the piston rings and skirts is high. This paper describes the Diesel RLE prototype constructed from a Cummins 4BT and the preliminary observations from initial low load testing. The critical technical challenge, namely the rotating liner face seal, appears to be operating with negligible gas leakage and within the hydrodynamic lubrication regime for the loads tested (peak cylinder pressures of the order of 80 bar).
Dardalis, Dimitrios, Hall, Matthew, Matthews, Ron, Basu, Amiyo, Ozel, Tayyar
Technical Paper
Optical Analysis on the Mixture Preparation and Combustion Behavior of Small Two-Stroke SI Engines Fueled with Alcohol-Blends2017-32-007811/05/2017
Small gasoline engines are used in motorcycles and handheld machinery, because of their high power density, low cost and compact design. The reduction of hydrocarbon emissions and fuel consumption is an important factor regarding the upcoming emission standards and operational expenses. The scavenging process of the two-stroke engine causes scavenging losses [1]. A reduction in hydrocarbon emissions due to scavenging losses can be achieved through a better understanding of the inner mixture formation. The time frame for fuel vaporization is limited using two-stroke SI engines by the high number of revolutions. With crank angle resolved optical methods it is possible to analyze the mixture formation behavior and combustion. A topic of these investigations is the use of alternative fuels such as alcohol- or butanol-blends and the analysis of their impact on the engine behavior. These fuels show high potential for further reduction of exhaust emissions while simultaneously increasing the
Weßling, Justus, Rauber, Fabian, Titus, Fabian, Beck, Kai W., Seidel, Tilman, Schweiger, Stefan, Schumann, Florian, Gegg, Tim
Technical Paper
Parametrical and Tribological Investigation of Ring Parameters Using Ring Dynamics Simulation for Blow-By, LOC and Friction Reduction2017-28-195407/10/2017
A local and global environmental concern regarding automotive emissions has led to optimize the design and development of Power train systems for IC engines. Blow-by and Engine oil consumption is an important source of hydrocarbon and particulate emissions in modern IC engines. Great efforts have been made by automotive manufacturers to minimize the impact of oil consumption and blow-by on in-cylinder engine emissions. This paper describes a case study of how simulation played a supportive role in improving piston ringpak assembly. The engine taken up for study is a six cylinder, turbocharged, water cooled diesel engine with a peak firing pressure of 140 bar and developing a power output of 227 KW at 1500 rpm. This paper reveals the influence of stepped land, top groove angle, ring face profile, twist features with regard to tweaking of Blow-by & LOC. Relevant design inputs of engine parameters were provided by the customer to firm up the boundary conditions. Predictive simulation
Santhanamm, Premkumarr, Sreejith, K., Anandan, Avinash
Technical Paper
Cost Efficient R&D Strategies to Meet Future Portfolio Challenges2017-01-192605/10/2017
Hatz is a medium sized engine manufacturer with a production volume of currently ~58000 engines per year and a rather diversified product portfolio. To be cost and time efficient in new and further developments of our engines a deep system knowledge is indispensable. In order to achieve this we use a strongly simulation based developing approach in combination with component and specially suited engine testing. This combines to a state-of-the art R&D process which helps us to overcome an increasingly cost challenging competition.
Winter, Tobias, Thierfelder, Simon
Technical Paper
A Study of the Friction of Oil Control Rings Using the Floating Liner Engine2016-01-104804/05/2016
The oil control ring (OCR) controls the supply of lubricating oil to the top two rings of the piston ring pack and has a significant contribution to friction of the system. This study investigates the two most prevalent types of OCR in the automotive market: the twin land oil control ring (TLOCR) and three piece oil control ring (TPOCR). First, the basis for TLOCR friction on varying liner roughness is established. Then the effect of changing the land width and spring tension on different liner surfaces for the TLOCR is investigated, and distinct trends are identified. A comparison is then done between the TLOCR and TPOCR on different liner surfaces. Results showed the TPOCR displayed different patterns of friction compared the TLOCR in certain cases.
Westerfield, Zachary, Liu, Yang, Kim, Dallwoo, Tian, Tian
Journal Article
Development of a High Speed Laser Induced Fluorescence (HSLIF) System in a Single Cylinder Engine for Oil Transport Studies2016-01-064204/05/2016
Understanding oil transport mechanisms is critical to developing better tools for oil consumption and piston skirt lubrication [1]. Our existing Two-Dimensional Laser Induced Fluorescence (2DLIF) system with an acquisition rate of 1 frame every one or two cycles was proven to be effective to display oil accumulation patterns and their evolution over many cycles in the piston ring pack system [2,3,4]. Yet, the existing system is unable to resolve instantaneous oil flow patterns in the piston-liner interface. In this work, a high-speed LIF system was developed. After a number of iterations the finalized high speed LIF system includes a 23 W, 100 kHz, 532 nm laser and a high speed camera capable of 100,000 FPS at 384 × 264 pixel resolution. After each component was selected, optimization of the quality of images taken from the system began. Each component in the optical system was tested for improvement of image quality; such components include: camera lens, beam expander, beam splitter
Zanghi, Eric, Tian, Tian
Technical Paper
A Study of the Friction of Oil Control Rings Using the Floating Liner Engine2016-01-1048-TEST-REC04/05/2016
The oil control ring (OCR) controls the supply of lubricating oil to the top two rings of the piston ring pack and has a significant contribution to friction of the system. This study investigates the two most prevalent types of OCR in the automotive market: the twin land oil control ring (TLOCR) and three piece oil control ring (TPOCR). First, the basis for TLOCR friction on varying liner roughness is established. Then the effect of changing the land width and spring tension on different liner surfaces for the TLOCR is investigated, and distinct trends are identified. A comparison is then done between the TLOCR and TPOCR on different liner surfaces. Results showed the TPOCR displayed different patterns of friction compared the TLOCR in certain cases.
Westerfield, Zachary, Liu, Yang, Kim, Dallwoo, Tian, Tian
Journal Article
Measuring the Impact of Engine Oils and Fuels on Low-Speed Pre-Ignition in Downsized Engines2014-01-121904/01/2014
One of the limits on the maximum fuel efficiency benefit to be gained from turbocharged, downsized gasoline engines is the occurrence of low speed pre-ignition (LSPI). LSPI may lead to high pressures and extreme knock (megaknock or superknock) which can cause severe engine damage. Though the mechanism leading to megaknock is not completely resolved, LSPI is thought to arise from local auto-ignition of areas in the cylinder which are rich in low ignition delay “contaminants” such as engine oil and/or heavy ends of gasoline. These contaminants are introduced to the combustion chamber at various points in the engine cycle (e.g. entering from the top land crevice during blow-down or washed from the cylinder walls during DI wall impingement). This paper describes a method for testing the propensity of different contaminants to cause a local pre-ignition in a gasoline engine. During one cycle, a small amount of contaminant is injected into one cylinder of a 4 cylinder engine. The spark is
Welling, Orian, Moss, James, Williams, John, Collings, Nick
Journal Article
Drivetrain Energy Distribution and Losses from Fuel to Wheel2013-01-911811/20/2013
Depending on a vehicles drive cycle, an improvement of the overall drivetrain efficiency does not necessarily have to go along with an improvement of its mileage. In here the ratio of energy to overcome rolling resistance, aerodynamic drag, acceleration and energy wasted directly in wheel brakes is responsible for potentially differing trends. A detailed knowledge of energy flows, sources and sinks makes up a substantial step into optimizing any drive train. Most fuel energy leaves the drivetrain via exhaust pipes. Next to usable mechanical energy, a big amount is spent to heat up the system directly or to overcome drive train friction, which is converted into heat to warm up the system additionally. An in depth quantification of the most important energy flows for an upper middle-sized class gasoline powered drive train is given as results of warm-up cycle simulations. Combustion engine heat losses are split into four paths to be compared with the heat of ten engine friction
Beulshausen, Johannes, Pischinger, Stefan, Nijs, Martin
Journal Article
Section Flow Improvement of Plasma Spray Cylinder in Outboard Motor2013-32-902910/15/2013
The two-stroke engines were in the main stream of the outboard motors, but they have been replaced with the four-stroke counterparts reflecting the environmental protection movement in recent years. However, the replacement with four-stroke engines involves increased number of components and additional displacement, and the outboard motors tend to be larger and heavier. This represents an issue, since the maneuverability of the boat is degraded due to the inappropriate weight distribution on the boat. Yamaha outboard motors F300B and VF250A, of which the production started in the year 2009, are equipped with four-stroke engines, and yet achieved the light weight equivalent to their two-stroke counterparts. The production volume of these models reached 20,000 units. The sleeveless cylinder block produced by utilizing the thermal spraying technology has successfully reduced the distance between the cylinders, and has contributed to realize smaller and lighter-weight components used in
Kumagai, Hideya
Technical Paper
Windage Tray Design Comparison Using Crankcase Breathing Simulation2013-01-058004/08/2013
The conflicting requirements of better fuel economy, higher performance and lower emissions from an automobile engine have brought many new challenges that require development teams to look beyond conventional test and seek answers from simulations. One of the relatively unexplored areas of development where frictional losses haven't been completely understood is the flow in the crankcase. Here computational engineering can play a significant role in analyzing flow field in a hidden and complex region where otherwise testing has serious limitations. Flow simulation in the crankcase poses significant complexity and provides an opportunity to enhance the understanding of underlying physics by using multi-physics analyses tools available commercially. In this study, air space under the piston and above the oil level in oil pan is simulated. It is known that bay-to-bay breathing and windage holes account for considerable amount of power losses in the crankcase. Therefore, this study is
Iqbal, Owais, Arora, Kunal
Technical Paper
Calculation of the Piston Assembly Friction: Classification, Validation and Interpretation2012-01-132304/16/2012
This SAE Technical Paper contains detailed data which are relevant for the calculation of the friction forces of the piston assembly in internal combustion engines. Useful ways of employing calculations besides measurements are exactly classified for the optimization of the piston assembly system in order to reduce friction losses. In the first step the theoretical basics for the calculation of the tribological system are introduced. Referring to the theory, the paper goes into detail about the basic set-up and the modeling degree of the calculation program. Furthermore, measured and calculated curves of friction forces are compared for different operating points. In addition, analysis of the crank-angle resolved friction force are presented with varying engine speeds, oil temperatures and loads and a detailed interpretation of the results is given. Concluding, the overall mechanical losses at the piston assembly are examined with regard to different operating parameters and are
Werner, Martin, Merkle, Andre, Graf, Stefan, Holzmüller, Roman, Wachtmeister, Georg
Technical Paper
The Study of Friction between Piston Ring and Different Cylinder Liners using Floating Liner Engine - Part 12012-01-133404/16/2012
The objective of this work was to develop an experimental system to support development and validation of a model for the lubrication of two-piece Twin-Land-Oil-Control-Rings (hereafter mentioned as TLOCR). To do so, a floating liner engine was modified by opening the head and crankcase. Additionally, only TLOCR was installed together with a piston that has 100 micron cold clearance to minimize the contribution of the skirt to total friction. Friction traces, FMEP trend, and repeatability have been examined to guarantee the reliability of the experiment results. Then, engine speed, liner temperature, ring tension, and land widths were changed in a wide range to ensure all three lubrication regimes were covered in the experiments. It was found that for each different ring land design, the measured instantaneous friction coefficient under different engine speed, liner temperature, and ring tension can roughly collapse to the same Stribeck curve, which indicates that the modified system
Liao, Kai, Chen, Haijie, Tian, Tian
Technical Paper
Recycling of Used Up Crankshaft Grinding Wheels2012-01-106004/16/2012
For sustainability in automobile manufacturing, recycle, reuse, and repair of used up cutting tools is now an established process. Although many types of tools were designed for one time use and then throw, an increasing awareness of the impact on the natural resources have made manufacturers to put some of these back to use or sell it back to suppliers who have put up a mechanism to extract the elements e.g. Tungsten and use it for manufacturing of new tools. There are many ways in which cutting tools can be recycled. Be it by reshaping a used up throwaway type tool [1], by redesigning of a tool holder for the use of unused cutting edges [2] or reusing short length drills that are used in making of long oil holes in crank case, cylinder head, cam shaft or connecting rods [3]. This paper demonstrates successful use of used up crankshaft grinding wheels. These used up grinding wheels can be reformed and used for grinding of many other automobile parts that require a new grinding wheel
Datar, Surendra
Technical Paper
Optimization of Semi-Floating Piston Pin Boss Formed by Using Oil-Film Simulations2012-01-090804/16/2012
This paper describes the oil-film bearing analysis simulation was utilized for the optimization of pin boss form which reduces a piston-pin noise. It is clear from the mechanism analysis of the piston-pin noise which is the last research that an oil-film flow inside a pin boss is an important factor for pin noise reduction. So, in this research, the oil-film simulation of the piston-pin-boss bearing part was performed using oil-film bearing analysis tool. After setting up the simulation conditions of the oil-film bearing part so that actual pin behavior and high correlativity might be shown, a parameter, effective hydrodynamic angular velocity, and an oil flow rate of change suitable for evaluation of a pin noise were found out. The pin noise in semi floating piston was reduced to the same level as full floating type by applying pin boss form to which each evaluation parameter becomes the optimal to a piston.
Nishikawa, Chihiro
Technical Paper
Crankcase Emission Control Test CodeJ900_201201 (Current)01/23/2012
The purpose of this SAE STandard is to provide standard test procedures for crankcase emission control systems and/or devices. The procedures included are for determining: a. The flow rate of the blowby of an engine; b. The flow rates through the crankcase emission control system inlet and outlet. This code is written to cover crankcase emission control systems which are designed to reduce the emission of engine blowby gases to the atmosphere. The code includes the following sections: 3. Definitions and Terminology; 4. Test Equipment; 5. Test Procedures; 6. Information and Data to be Recorded; 7. Data Analysis; 8. Presentation of Information and Data.
SAE IC Powertrain Steering Committee
Technical Standard
Research on Noise Reduction of Linkage Drive Gear in Extended Expansion Linkage Engine2011-32-053811/08/2011
The authors have reported on a study on extended expansion linkage engine to enhance thermal efficiency since 2006. This report discusses the use of a test engine applied to a Micro Combined Heat and Power Generation Unit for household use, in order to reduce engine noise at a rated operation. Test engine noise is mainly caused by gear meshing for the multiple linkage system, so helical gear with higher contact ratio than that of spur gear was used. Measurement of engine noise revealed that test engine noise increased by 3.2 dB(A) over compared conventional engine. From results of behavior analysis by mechanical simulation, when transmission direction of the relative torque between the crankshaft and the eccentric shaft is reversed, the direction of the thrust force acting on the gear is reversed. For this reason, the test engine noise increases because each shaft vibrates, and rattle noise occurs. With the aim of reducing rattle noise, it is possible to control axial vibration using
Naoe, Gaku, Tokubi, Kota
Technical Paper
Friction between Piston and Cylinder of an IC Engine: a Review2011-01-140504/12/2011
Engine friction serves as an important domain for study and research in the field of internal combustion engines. Research shows that friction between the piston and cylinder accounts for almost 20% of the losses in an engine and therefore any effort to minimize friction losses will have an immediate impact on engine efficiency and thus vehicle fuel economy. The two most common methods to experimentally measure engine friction are the floating liner method and the instantaneous indicated mean effective pressure (IMEP) method. This paper provides a detailed review of the IMEP method, presents major findings, and discusses sources of error. Although the instantaneous IMEP method is relatively new compared to the floating liner method, it has been used by many scientists and engineers for calculating piston ring assembly friction with consistent results. It should be noted that irrespective of the method utilized, most of the experiments are conducted under motoring conditions and limited
Nagar, Pranay, Miers, Scott
Technical Paper
CFD Analysis of Oil/Gas Flow in Piston Ring-Pack2011-01-140604/12/2011
The oil consumption and blow-by are complex phenomena that need to be minimized to meet the ever changing modern emission standards. Oil flows from the sump to the combustion chamber and the blow-by gases flow from the combustion chamber to the crank case. There are several piston rings on the piston, which form a ring-pack. The ring pack has to be efficiently designed to minimize the oil consumption and blow-by. Since it is difficult and extremely costly to conduct experiments on every series of engines to check for the blow-by and oil consumption, a CFD analysis can be performed on the ring pack to study the blow-by and oil-consumption characteristics. In the CFD analysis described here, the region considered is between the compression chamber and the skirt, between the piston (including the rings) and the cylinder liner. The 3D CFD analysis was conducted for the engine running conditions of 5000 rpm and load of 13.5 kPa, for a 2.4L gasoline engine. The inertia force was provided as
Puthiya Veettil, Mahesh, Shi, Fanghui
Technical Paper
Visualization of a Fired Two-Stroke Chain Saw Engine Running at Idle Speed by Dynamic Neutron Radiography2010-32-001309/28/2010
Dynamic neutron radiography is a non-destructive inspection method. It provides different attenuation contrast compared, e.g., to common X-ray imaging. This allows neutrons to penetrate centimeter thick layers of metals while fuel or lubricants can still deliver good visibility. With beam cross sections between 3 cm and 30 cm (squared), neutron radiography is an ideal tool for the visualization of running combustion engines. Here we report on an experiment that demonstrates the feasibility to visualize a fired two-stroke chain saw engine running at idle speed (~ 3000 rpm). A sequence of single frames of the running engine was recorded and combined into a movie which provides a view into the moving parts of the engine, the combustion chamber and the crank case.
Gruenzweig, Christian
Technical Paper
Study on Similarity of Pumping Flow in Engine Crankcase2009-32-005111/03/2009
For the prediction of pumping loss in the engine crankcase at the early stage of engine design, a similarity law of the pumping loss on parallel cylinders with the phase difference of 180 degrees has been derived from the sum of the power loss due to the drag force of airflow through the cylinder bulkhead holes and the inertia force of fluid. It has been found that the mean effective pressure in the crankcase is in proportion to the square of the mean flow velocity at the bulkhead holes. Then, in order to validate the similarity law, by using a prototype engine with inline four cylinders, the pumping loss was estimated by subtracting the frictional loss with special pistons that had air holes, from the power loss in which the area of the bulkhead holes and engine speed were changed. The experimental results of the pumping loss were normalized by the similarity law. As a consequence, it has been shown that the pumping loss obeys the law. Thus, the similarity law is valid for pumping
Arisawa, Hidenori, Nishimura, Motohiko, Watanabe, Hiroyuki, Ueshima, Atsushi, Arima, Kazuki, Yamasaki, Akiyuki
Technical Paper
Weight and Friction Optimized Cranktrain Design Supported by Coupled CAE Tools2009-01-145204/20/2009
Due to the contradiction of the market demands and legal issues OEMs are forced to invest in finding concepts that assure high fuel economy, low exhaust emissions and high specific power at the same time. Since mechanical losses may amount up to 10 % of the fuel energy, a key to realise such customer/government specific demands is the improvement of the mechanical performance of the engines, which comprises mainly friction decrease and lightweight design of the engine parts. In order to achieve the mentioned objectives, it has to be checked carefully for each component whether the design potentials are utilized. Many experimental studies show that there is still room for optimization of the cranktrain parts, especially for the crankshaft. A total exploitation of the crankshaft potentials is only possible with advanced calculation approaches that ensure the component layout within design limits. This paper illustrates a calculation procedure which focuses on the borderline design of
Cevik, M. Cagri, Rebbert, Martin, Maassen, Franz
Technical Paper
Investigation of Combustion Robustness in Catalyst Heating Operation on a Spray Guided DISI Engine2009-01-148904/20/2009
In catalyst heating operation for DISI (Direct Injection Spark Ignition) engines, split injection has been generally known to improve combustion stability which is critical for the trade-off between tailpipe emissions and vehicle idle NVH. This is also the case for a spray guided DISI engine employing multi-hole injectors and with both injector and spark plug centrally located in the chamber. There are some special challenges with regard to combustion robustness because of the close proximity between injector and spark plug. Investigations have been carried out through engine testing and CFD simulation to ensure combustion robustness. For catalyst heating operation, the first injection occurs during induction, which forms a relatively well mixed but lean mixture in the cylinder before ignition, and the second injection occurs close to ignition, which produces a stratified fuel rich mixture in the central region of the combustion chamber. Combustion initialization is found to be
Chen, Xiangdong, Fu, Huiyu, Smith, Stephen, Sandford, Malcolm
Technical Paper
Acoustic Holography Techniques in Automotive NVH2009-26-004901/21/2009
Acoustic Holography is emerging as a powerful, high-resolution noise source localization technique in this decade. Compared to conventional sound intensity measurement, Acoustic Holography scores because of its ability to provide on-line visualization of acoustic energy distribution of the sources perform measurements during stationary and transient conditions and it is substantially faster and easier. Further, with Near Field Acoustic Holography (NAH) and Beam-Forming (BF) techniques, it is possible to cover wide range of frequencies with reasonable investment. This paper compares and evaluates the advantages of the Acoustic Holography technique with conventional Sound Intensity Mapping for different applications such as noise mapping of a vehicle, noise source identification of engine and other small sized components. It also discusses how this technique can be extended to moving sources such as noise source identification during pass-by. Using types of array designs, it is possible
Megavannan, J., Gaikwad, A. A., Ramachandran, E., Raju, S.
Technical Paper
Noise Source Identification Techniques Comparison2008-36-020210/07/2008
Now a day's several techniques are used to help in noise source identification. This paper intends to comment compare some of them including advantages and disadvantages. We will show the results of the follows techniques: Experimental Modal Analysis Operational Modal Analysis Acoustic Holography Sound Intensity This discussion will be based on a high speed diesel engine crankcase which is applied in a SUV and the focus was to improve the Cab Articulation Index (AI).
Glyniadakis, Georges Vretos, Rodrigues, Marlon Casagrande, Pecula, Mauro Miguel, de Souza, Alexandre Barcelos
Technical Paper
Crankcase Flow Modeling for a Racing Motorcycle Engine2007-01-026604/16/2007
When designing a sump system for a high performance engine the choice of the size of the inter-bay breathing passages is critical. The passages should be chosen to minimize the crankcase pumping loss and oil aeration while still maintaining adequate removal of blow-by gases and a good block structure. This paper presents an approach to the modeling of engine crankcase gas flow using Ricardo WAVE software. The model was developed during the design of a dry sump version of a racing engine and was validated using pressure and blow-by data. The model was used to quantify gas velocities, pressure fluctuations and power loss due to the pumping of crankcase gas. The effects of changes to a series of parameters such as breather hole size, sump volume, engine size and crankcase compression ratio were quantified. This approach provides useful guidance in the design of dry sump systems at the concept design stage.
Deighan, Thomas, Zuhdi, Naji
Technical Paper
Emissions and Performance Potential of a Small Stratified Charge 2-Stroke Engine Using Reed Valves2006-32-005811/13/2006
Stratified concepts offer a reduction of the scavenging losses of 2-stroke engines. STIHL has developed a stratified reed valve engine to comply with Phase2 emissions, introduced into the market in the new STIHL Cutquik™ TS 700. The engine with a displacement of 98,5 cm3 offers performance and product specifications that exceed its conventional predecessor. The results of the engine optimization process including flow simulation, concept evaluation and combustion process development are presented. The paper focuses on the design specifications of the air head carburetor and the specific layout of the reed valve scavenging process. Further, a cyclone type air filter system is presented. The engine today meets the FEL 72 g/kWh limit. The concept offers further potential to improve trapping and volumetric efficiency, enabling a power and torque increase as well as emission control for the future.
Moeser, Christian M., Gantert, Jochen, Keck, Ulrich, Raffenberg, Michael, Rieber, Martin, Rosskamp, Heiko
Technical Paper
A Study on the Mechanism of Lubricating Oil Consumption of Diesel Engines - 4th Report: The Measurement of Oil Pressure Under the Piston Oil Ring -2006-01-344010/16/2006
Clarifying the mechanism of the oil consumption of engines is necessary for developing its estimation method. Oil moves upwards on the piston to the combustion chamber through ring sliding surfaces, ring backs and ring gaps. The mechanisms of oil upwards transport through the ring gaps are hardly analyzed. In this report, oil pressure just under the oil ring was successfully measured by newly developed method to clarify the oil transport mechanism at the ring gap. It was showed that the generated oil pressure pushed up the oil at the ring gap.
Ito, Akemi, Tsuchihashi, Keiichi, Nakamura, Masaaki
Technical Paper
Technology for Cylinder Deactivation2005-01-007704/11/2005
The paper deals with maintaining the efficiency of the engine at different loading conditions. In a 6 cylinder engine, when it is fully loaded it operates with maximum efficiency. But at partly loaded condition, its efficiency drops down. In this paper a 6 cylinder engine is converted into a 4 cylinder engine, so that the part load for 6 cylinder engine acts as a near full load for 4 cylinder engine. For this, the crankshaft is divided into a number of segments, so that it will be possible to disengage two of the cylinders from the other four cylinders. During this conversion, servo motor is used to vary the crank angle according to the number of cylinders, which in turn is controlled by ECU (Electronic Control Unit). Even though the cylinder deactivation can also be done by cutting down the fuel supply for one or two cylinders, still the deactivated cylinder produces frictional power loss. By adopting the method in this paper, this loss can be avoided and the engine will also run at
Vinodh, B.
Technical Paper
AN ELECTRONIC INCYLINDER INJECTION SYSTEM FOR A TWO STROKE SPARK IGNTION ENGINE2003-28-000808/22/2003
In the present paper, investigations relating to the development of an electronic in-cylinder injection system for a two stroke spark ignition are briefly described. These include the major components used including the laboratory developed manual electronic control system. Preliminary studies have shown an improved performance of the in-cylinder injection system as compared to the conventional carburetor system.
Siddiqui, A.I., Wani, Marouf, Bhatti, T.S., Gajendra Babu, M.K.
Technical Paper
Mounting Flanges and Power Take-Off Shafts for Small EnginesJ609_200307 (Current)07/16/2003
This SAE Recommended Practice was developed to provide a method of recommending the availability of various dimensional output shaft and crankcase flange combinations.
Small Engine and Powered Equipment Committee
Recommended Practice
Dynamic Simulation of a Piston for Compressor Application and Correlation with Bench Tests2003-01-110603/03/2003
Piston dynamic analysis has widely been used to address and understand the phenomena between the sliding surfaces of the piston and bore and the lubrication conditions between them. One of the numerical analysis that can be done is the evaluation of hydrodynamic behavior in order to reduce the sliding resistance as much as possible, reducing friction due to mechanical and thermal loads exerted from the piston skirt to the rigid bore. This analysis is typically done in internal combustion piston applications. This paper presents an analysis through dynamic simulation of a piston for a compressor application used in the brake system of commercial vehicles Class 5 through Class 8. Several modifications of the piston profile and ovality were done to optimize the results in product validation and improve product performance for compressor applications. The result was a good correlation between the dynamic simulation outputs and the product validation tests.
Ramos, Elías B., Cabrera, Alfredo R., Regalado, Samuel, Soria, Alberto
Technical Paper
Why are NCI Pistons Not Used in Heavy Duty Diesel Engines?2002-01-016403/04/2002
In order to meet the strict exhaust emission legislation and customer's requirements of high power, heavy-duty diesel engines have to have a higher peak firing pressure and higher thermal load recently. It causes serious influence on the reliability and durability of the engines and engine parts, pistons in particular. The pistons for the next generation heavy-duty diesel engines are required to withstand more than 20 MPa of the peak firing pressure and higher thermal load, productivity of course. Nodular cast iron (NCI) pistons are one of the answers that could satisfy the requirements mentioned above. It is well known that NCI pistons have a lot of advantages but not popular. The difficulty of the casting technology and the quality control are the major reasons. Hino P11C engine has adopted it and kept it under mass production since 1991 and approx.20000 units of total production volume without any troubles. Newly developed gravity die casting technology could remove these problems
Metoki, Satoshi, Negishi, Hideo
Technical Paper
Improving the Performance of Two-Stroke Spark Ignition Engine by Direct Injection2001-01-184312/01/2001
Two Stroke Spark Ignition Engines have high exhaust emissions and low brake thermal efficiency due to the short-circuiting losses and incomplete combustion, which occur during idling and at part-load operating conditions. In the present work an attempt was made to eliminate the short-circuiting losses by direct injection. A low-pressure direct fuel injection system was developed with the Bosch electric fuel pump and solenoid injector. The necessary electronic control unit hardware and software were developed in the institute for research purpose. The present work was conducted in three phases. In the first phase the carburetor was replaced by the manifold injection system and the performance of the system was optimized for minimum emissions. In the second phase the extra reed valve concept reference (10) was implemented on the manifold injection system to improve scavenging. In the final phase the direct injection system was developed which eliminates short-circuiting losses completely
Ramakrishnan., E, Nagalingam, B, Gopalakrishnan, K.V
Technical Paper
Simulation of the Piston and Piston Ring Dynamic2001-01-336810/01/2001
All reciprocating engines from the first Diesel engine to turbocharged formula 1 engines require a sealing of the combustion chamber. This sealing is realized by the compression rings. Today a set of two compression rings and one oil control ring is standard, the large variety of available solution demonstrate the continuous effort and attention paid to an optimized system performance since the first engine was started. The complexity of the interactions with the mechanical, thermal, thermodynamic, tribologic, dynamic behavior of the piston still requires mechanical testing of the various components before release to series production. This procedure can be shortened by use of simulation models reflecting the real behavior in detail to select the most promising combinations of components and characteristics. This paper presents the model to simulate the dynamic motion of the piston as function of the liner and piston geometry, the surface quality and the thermal and thermodynamic
Haubner, Frank Georg
Technical Paper
Piston Related Noise with Diesel Engines Parameters of Influence and Optimization2001-01-333510/01/2001
Different procedures leading to the minimization of piston related noise with Diesel engines will be introduced. Along with the method for subjective noise assessment a fast way for measurable quantification of piston noise will also be described. The influences of pin bore offset, piston profile and installation clearance on the noise excitation will be shown using calculation examples and measurement results.
Künzel, Reiner, Werkmann, Martin, Tunsch, Michael
Technical Paper
Potentials of a Piezo-Driven Passenger Car Common Rail System to Meet Future Emission Legislations - An Evaluation by Means of In-Cylinder Analysis of Injection and Combustion2001-01-349909/24/2001
Future exhaust gas limits for diesel-driven passenger cars will force the automotive industry to significantly improve the design of the vehicles respectively of the drive assemblies. Especially the contributions of soot and nitrogen oxide will be the main problems in the future. One possible solution could be the application of suitable exhaust gas aftertreatment systems, but since modern common rail injection systems deliver more degrees of freedom referring to the injection process, again the optimisation of the injection process could offer a possibility to meet the exhaust gas limits. In this study, a passenger car common rail system, applied to an optically accessible transparent engine based on the AUDI V6 TDI engine, was investigated using a solenoid-driven and a piezo-driven injector, both equipped with the same injection nozzle. When using a pre-injection for the solenoid-driven injector, spatial coexistence of spray and flame could be observed over a large part of the engine
Fettes, C., Leipertz, A.
Technical Paper
Prediction of State of Gas Inside an I.C. Engine During Exhaust Blow Down Process2001-26-002201/10/2001
Prediction of state of gas inside an I.C.Engine cylinder during exhaust blow down process, is needed for optimizing exhaust port size and lead height relative to transfer port in case of a two stroke engine. The exhaust Blow Down Process (EBDP), here refers to a process which occurs as soon as the exhaust port opens, venting burnt charge accompanied by reduction in pressure, temperature, density & mass inside the barrel until atmospheric pressure or manifold pressure is attained. The analysis predicts variations of pressure, density, temperature and mass flow rate with crank angle and time. The results are also interpreted in terms of lead height requirements. A lead height reduction of about 3 mm can cause about 35% decrease in mass flow rate during the initial part of induction process i.e. transfer process.
Mukesh, U.M., Reddy, P.V.
Technical Paper
Real-Time Steady-State Measurement of PCV-Contribution to Oil Consumption on Ford 4.6 L SI-Engine2000-01-287610/16/2000
Real-time engine oil consumption has been measured at 21 steady-state conditions for a fully broken-in 2-valve Ford 4.6L SI-engine. The sampling location was at the engine stack and the measurement technique was the Southwest Research Institute (SwRI) developed SO2-analyzer for real-time oil consumption measurement, referred to as SwRI RTOC-II. PCV contribution to oil consumption was determined by measuring the oil consumption with and without the inclusion of positive crank case ventilation (PCV) flow, which is a differental approach. This method has not been correlated to real world vehicle usage but is valuable for making A-to-B comparisons. The paper is important since it presents novel data for real-time steady-state PCV-contribution to oil consumption.
Froelund, K.
Technical Paper
Modeling of Piston-Cylinder Lubrication with a Flexible Skirt and Cylinder Wall2000-01-280410/16/2000
This paper demonstrates the effect of elastic deformation of the cylinder wall on the lubrication between the skirt and cylinder with simulation results of two realistic examples. The simulation methodology is described. Cylinder flexibility caused substantial changes in slap motion, average and peak wear loads on the skirt, friction, and power losses due to asperity contact and hydrodynamic friction. Cylinder deflection due to side loads was about ten percent of the skirt deflection due to side loads, and deformation due to cylinder gas pressure was substantial.
Perchanok, Mathias
Technical Paper
Lightweight design~A challenge for modern passenger car engines2000-05-005106/12/2000
The application of lightweight materials for new crankcase concepts implies comprehensive design considerations to achieve weight reductions as close as possible to the potential of the selected material. A specific approach for inline and V-engine crankcase concepts is discussed in detail. Engine weight reduction can also be achieved through "Downsizing." Modern technologies applied to existing engine concepts increase the power-weight ratio, the engine''s capability and therefore its marketing value. The use of lightweight materials for diesel and gasoline engines within one engine family allows a combined production and a less costly machining. Aluminum and magnesium alloys are, due to their high relative strength (tensional strength and e-modulus divided by their material densities), suitable for weight-reduced components which need to be designed for a specific target strength. However, the low absolute values of tensional strength and e-modulus must be taken into account by
Beste, Frank, Schoffmann, Wolfgang, Marquard, Ralf
Technical Paper
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