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Viewing 271 to 300 of 33500
2017-09-04
Technical Paper
2017-24-0025
Francesco Sapio, Andrea Piano, Federico Millo, Francesco Concetto Pesce
Abstract Development trends in modern Common Rail Fuel Injection System (FIS) show dramatically increasing capabilities in terms of optimization of the fuel injection pattern through a constantly increasing number of injection events per engine cycle along with a modulation and shaping of the injection rate. In order to fully exploit the potential of the abovementioned fuel injection pattern optimization, numerical simulation can play a fundamental role by allowing the creation of a kind of a virtual injection rate generator for the assessment of the corresponding engine outputs in terms of combustion characteristics such as burn rate, emission formation and combustion noise (CN). This paper is focused on the analysis of the effects of digitalization of pilot events in the injection pattern on Brake Specific Fuel Consumption (BSFC), CN and emissions for a EURO 6 passenger car 4-cylinder diesel engine.
2017-09-04
Technical Paper
2017-24-0026
Davide Paredi, Tommaso Lucchini, Gianluca D'Errico, Angelo Onorati, Stefano Golini, Nicola Rapetto
Abstract The scope of the work presented in this paper was to apply the latest open source CFD achievements to design a state of the art, direct-injection (DI), heavy-duty, natural gas-fueled engine. Within this context, an initial steady-state analysis of the in-cylinder flow was performed by simulating three different intake ducts geometries, each one with seven different valve lift values, chosen according to an estabilished methodology proposed by AVL. The discharge coefficient (Cd) and the Tumble Ratio (TR) were calculated in each case, and an optimal intake ports geometry configuration was assessed in terms of a compromise between the desired intensity of tumble in the chamber and the satisfaction of an adequate value of Cd. Subsequently, full-cycle, cold-flow simulations were performed for three different engine operating points, in order to evaluate the in-cylinder development of TR and turbulent kinetic energy (TKE) under transient conditions.
2017-09-04
Technical Paper
2017-24-0027
Nearchos Stylianidis, Ulugbek Azimov, Nobuyuki Kawahara, Eiji Tomita
Abstract A chemical kinetics and computational fluid-dynamics (CFD) analysis was performed to evaluate the combustion of syngas derived from biomass and coke-oven solid feedstock in a micro-pilot ignited supercharged dual-fuel engine under lean conditions. For this analysis, a reduced syngas chemical kinetics mechanism was constructed and validated by comparing the ignition delay and laminar flame speed data with those obtained from experiments and other detail chemical kinetics mechanisms available in the literature. The reaction sensitivity analysis was conducted for ignition delay at elevated pressures in order to identify important chemical reactions that govern the combustion process. We have confirmed the statements of other authors that HO2+OH=H2O+O2, H2O2+M=OH+OH+M and H2O2+H=H2+HO2 reactions showed very high sensitivity during high-pressure ignition delay times and had considerable uncertainty.
2017-09-04
Technical Paper
2017-24-0028
Adèle Poubeau, Stephane Jay, Anthony Robert, Edouard Nicoud, Christian Angelberger
Abstract This study presents a preliminary application of Large-Eddy Simulations (LES) of a speed transient performed on a motored single-cylinder engine. The numerical setup follows a methodology which has been validated and optimized for stabilized operating points in previous work, and adapted to run a speed transient of 31 cycles, from 1000 to 1800 rpm. Analysis of the results contributes to characterize the impact of the transient on the engine charge, tumble motion and velocity distribution. These simulations, which have never been performed in the past (to the best of our knowledge), represent a decisive step towards modeling and understanding transient in GDI engines, and particularly their impact on soot particle emissions in real driving conditions.
2017-09-04
Technical Paper
2017-24-0030
Vesselin Krassimirov Krastev, Luca Silvestri, Giacomo Falcucci, Gino Bella
Abstract A two-equation Zonal-DES (ZDES) approach has been recently proposed by the authors as a suitable hybrid URANS/LES turbulence modeling alternative for Internal Combustion Engine flows. This approach is conceptually simple, as it is all based on a single URANS-like framework and the user is only required to explicitly mark which parts of the domain will be simulated in URANS, DES or LES mode. The ZDES rationale was initially developed for external aerodynamics applications, where the flow is statistically steady and the transition between zones of different types usually happens in the URANS-to-DES or URANS-to-LES direction. The same “one-way” transition process has been found to be fairly efficient also in steady-state internal flows with engine-like characteristics, such as abrupt expansions or intake ports with fixed valve position.
2017-09-04
Technical Paper
2017-24-0029
Tommaso Lucchini, Gianluca D'Errico, Tarcisio Cerri, Angelo Onorati, Gilles Hardy
Abstract Computational fluid dynamics represents a useful tool to support the design and development of Heavy Duty Engines, making possible to test the effects of injection strategies and combustion chamber design for a wide range of operating conditions. Predictive models are required to ensure accurate estimations of heat release and the main pollutant emissions within a limited amount of time. For this reason, both detailed chemistry and turbulence chemistry interaction need to be included. In this work, the authors intend to apply combustion models based on tabulated kinetics for the prediction of Diesel combustion in Heavy Duty Engines. Four different approaches were considered: well-mixed model, presumed PDF, representative interactive flamelets and flamelet progress variable. Tabulated kinetics was also used for the estimation of NOx emissions.
2017-09-04
Technical Paper
2017-24-0032
Gilles Decan, Stijn Broekaert, Tommaso Lucchini, Gianluca D'Errico, Jan Vierendeels, Sebastian Verhelst
Abstract The present work details a study of the heat flux through the walls of an internal combustion engine. The determination of this heat flux is an important aspect in engine optimization, as it influences the power, efficiency and the emissions of the engine. Therefore, a set of simulation tools in the OpenFOAM® software has been developed, that allows the calculation of the heat transfer through engine walls for ICEs. Normal practice in these types of engine simulations is to apply a wall function model to calculate the heat flux, rather than resolving the complete thermo-viscous boundary layer, and perform simulations of the closed engine cycle. When dealing with a complex engine, this methodology will reduce the overall computational cost. It however increases the need to rely on assumptions on both the initial flow field and the behavior in the near-wall region.
2017-09-04
Technical Paper
2017-24-0033
Priyanka Dnyaneshwar Jadhav, J M Mallikarjuna
Abstract Future stringent emission norms are impelling researchers to look for new emission control techniques. Today, gasoline direct injection (GDI) engines are becoming more popular because of high potential to reduce exhaust emissions over a wide operating load range, unlike conventional port fuel injection (PFI) engines. Also, turbocharged GDI engines allow engine downsizing with a certain restriction on compression ratio (CR) due to knocking tendency, thereby limiting the fuel economy. However, use of exhaust gas recirculation (EGR) delays combustion and lowers the knocking tendency which will aid in improving the fuel economy. Therefore, this study is aimed to evaluate the effect of EGR rate on the performance and emission characteristics of a two-liter turbocharged four-stroke GDI engine by computational fluid dynamics (CFD) analysis. For the analysis, the CR of 9.3 and the engine speed of 1000 rev/min., are selected.
2017-09-04
Technical Paper
2017-24-0034
Michele Battistoni, Carlo N. Grimaldi, Valentino Cruccolini, Gabriele Discepoli, Matteo De Cesare
Abstract Water injection in highly boosted gasoline direct injection (GDI) engines has become an attractive area over the last few years as a way of increasing efficiency, enhancing performance and reducing emissions. The technology and its effects are not new, but current gasoline engine trends for passenger vehicles have several motivations for adopting this technology today. Water injection enables higher compression ratios, optimal spark timing and elimination of fuel enrichment at high load, and possibly replacement of EGR. Physically, water reduces charge temperature by evaporation, dilutes combustion, and varies the specific heat ratio of the working fluid, with complex effects. Several of these mutually intertwined aspects are investigated in this paper through computational fluid dynamics (CFD) simulations, focusing on a turbo-charged GDI engine with port water injection (PWI). Different strategies for water injection timing, pressure and spray targeting are investigated.
2017-09-04
Technical Paper
2017-24-0035
Giulio Cazzoli, Claudio Forte, Gian Marco Bianchi, Stefania Falfari, Sergio Negro
Abstract The laminar burning speed is an important intrinsic property of an air-fuel mixture determining key combustion characteristics such as turbulent flame propagation. It is a function of the mixture composition (mixture fraction and residual gas mass fraction) and of the thermodynamic conditions. Experimental measurements of Laminar Flame Speeds (LFS) are common in literature, but initial pressure and temperature are limited to low values due to the test conditions: typical pressure values for LFS detection are lower than 25 bar, and temperature rarely exceeds 550 K. Actual trends in spark ignition engines are to increase specific power output by downsizing and supercharging, thus the flame front involves even more higher pressure and temperature since the beginning of combustion.
2017-09-04
Technical Paper
2017-24-0003
Andreas Sidorow, Vincent Berger, Ghita Elouazzani
Abstract Gasoline engines have typically a waste gate actuator to control the boost pressure. The electrification of the vehicle and combustion engine components leads to new challenges of application of electric actuators in engine components, like turbochargers, which are faced with relatively high ambient temperatures. Another challenge is a simulation and prediction of the mechanical load on the actuator and kinematic components at different application scenarios, which can help to find the optimal solution which fulfills the durability, controllability, etc. targets. This paper deals with a physical dynamic model of an electric waste-gate actuator and kinematic components. The modeling includes a thermal, electrical and mechanical parts of the turbocharger control system and is validated on test-bench and engine measurements including pulsation effects.
2017-09-04
Technical Paper
2017-24-0002
Adrian Irimescu, Silvana Di Iorio, Simona Merola, Paolo Sementa, Bianca Maria Vaglieco
Abstract Quasi-dimensional modeling is used on a wide scale in engine development, given its potential for saving time and resources compared to experimental investigations. Often it is preferred to more complex CFD codes that are much more computationally intensive. Accuracy is one major issue of quasi-dimensional simulations and for this reason sub-models are continuously developed for improving predictive capabilities. This study considers the use of equivalent fluid velocity and characteristic length scales for simulating the processes of fresh charge entrainment and oxidation behind the flame front. Rather than dividing combustion into three different phases (i.e. laminar kernel, turbulent flame propagation and oxidation near the walls), the concept of turbulent heat and mass transfer is imposed throughout the entire process.
2017-09-04
Technical Paper
2017-24-0006
Alejandro Aljure, Xavier Tauzia, Alain Maiboom
Abstract Diesel engines are being more commonly used for light automotive applications, due to their higher efficiency, despite the difficulty of depollution and extra associated costs. They require more accessories to function properly, such as turbocharging and post-treatment systems. The most important pollutants emitted from diesel engines are NOx and particles (in conventional engines), being difficult to reduce and control because reducing one increases the other. Low temperature combustion (LTC) diesel engines are able to reduce both pollutants, but increase emissions of CO and HC. Besides HCCI and EGR systems, one method that could achieve LTC conditions is by using multiple injections (pilot/main, split injection, etc.). However, understanding multiple diesel injection is no easy task, so far done by trial and error and complex 3D CFD models, or too simplified by 0D models.
2017-09-04
Technical Paper
2017-24-0009
Federico Millo, Giulio Boccardo, Andrea Piano, Luigi Arnone, Stefano Manelli, Giuseppe Tutore, Andrea Marinoni
Abstract To comply with Stage IV emission standard for off-road engines, Kohler Engines has developed the 100kW rated KDI 3.4 liters diesel engine, equipped with DOC and SCR. Based on this engine, a research project in collaboration between Kohler Engines, Ricardo, Denso and Politecnico di Torino was carried out to exploit the potential of new technologies to meet the Stage IV and beyond emission standards. The prototype engine was equipped with a low pressure cooled EGR system, two stage turbocharger, high pressure fuel injection system capable of very high injection pressure and DOC+DPF aftertreatment system. Since the Stage IV emission standard sets a 0.4 g/kWh NOx limit for the steady state test cycle (NRSC), that includes full load operating conditions, the engine must be operated with very high EGR rates (above 30%) at very high load.
2017-09-04
Technical Paper
2017-24-0007
Joachim Beeckmann, Raik Hesse, Felix Bejot, Nan Xu, Heinz Pitsch
Abstract Especially for internal combustion engine simulations, various combustion models rely on the laminar burning velocity. With respect to computational time needed for CFD, the calculation of laminar burning velocities using a detailed chemical mechanism can be replaced by incorporation of approximation formulas, based on rate-ratio asymptotics. This study revisits an existing analytical approximation formula [1]. It investigates applicable temperature, pressure, and equivalence ratio ranges with special focus on engine combustion conditions. The fuel chosen here is methane and mixtures are composed of methane and air. The model performance to calculate the laminar burning velocity are compared with calculated laminar burning velocities using existing state of the art detailed chemical mechanisms, the GRI Mech 3.0 [2], the ITV RWTH [3], and the Aramco mechanism [4].
2017-09-04
Technical Paper
2017-24-0010
Federico Millo, Luciano Rolando, Alessandro Zanelli, Francesco Pulvirenti, Matteo Cucchi, Vincenzo Rossi
Abstract This paper presents the modeling of the transient phase of catalyst heating on a high-performance turbocharged spark ignition engine with the aim to accurately predict the exhaust thermal energy available at the catalyst inlet and to provide a “virtual test rig” to assess different design and calibration options. The entire transient phase, starting from the engine cranking until the catalyst warm-up is completed, was taken into account in the simulation, and the model was validated using a wide data-set of experimental tests. The first step of the modeling activity was the combustion analysis during the transient phase: the burn rate was evaluated on the basis of experimental in-cylinder pressure data, considering both cycle-to-cycle and cylinder-to-cylinder variations.
2017-09-04
Journal Article
2017-24-0012
Andrea Piano, Giulio Boccardo, Federico Millo, Andrea Cavicchi, Lucio Postrioti, Francesco Concetto Pesce
Abstract Nowadays, injection rate shaping and multi-pilot events can help to improve fuel efficiency, combustion noise and pollutant emissions in diesel engine, providing high flexibility in the shape of the injection that allows combustion process control. Different strategies can be used in order to obtain the required flexibility in the rate, such as very close pilot injections with almost zero Dwell Time or boot shaped injections with optional pilot injections. Modern Common-Rail Fuel Injection Systems (FIS) should be able to provide these innovative patterns to control the combustion phases intensity for optimal tradeoff between fuel consumption and emission levels.
2017-09-04
Technical Paper
2017-24-0015
Luigi Teodosio, Vincenzo De Bellis, Fabio Bozza, Daniela Tufano
Abstract Nowadays different technical solutions have been proposed to improve the performance of internal combustion engines, especially in terms of Brake Specific Fuel Consumption (BSFC). Its reduction of course contributes to comply with the CO2 emissions legislation for vehicle homologation. Concerning the spark ignition engines, the downsizing coupled to turbocharging demonstrated a proper effectiveness to improve the BSFC at part load. On the other hand, at high load, the above solution highly penalizes the fuel consumption mainly because of knock onset, that obliges to degrade the combustion phasing and/or enrich the air/fuel mixture. A promising technique to cope with the above drawbacks consists in the Variable Compression Ratio (VCR) concept. An optimal Compression Ratio (CR) selection, in fact, allows for further improvements of the thermodynamic efficiency at part load, while at high load, it permits to mitigate knock propensity, resulting in more optimized combustions.
2017-09-04
Journal Article
2017-24-0014
Fabio Bozza, Vincenzo De Bellis, Pietro Giannattasio, Luigi Teodosio, Luca Marchitto
Abstract The technique of liquid Water Injection (WI) at the intake port of downsized boosted SI engines is a promising solution to improve the knock resistance at high loads. In this work, an existing 1D engine model has been extended to improve its ability to simulate the effects of the water injection on the flame propagation speed and knock onset. The new features of the 1D model include an improved treatment of the heat subtracted by the water evaporation, a newly developed correlation for the laminar flame speed, explicitly considering the amount of water in the unburned mixture, and a more detailed kinetic mechanism to predict the auto-ignition characteristics of fuel/air/water mixture. The extended 1D model is validated against experimental data collected at different engine speeds and loads, including knock-limited operation, for a twin-cylinder turbocharged SI engine.
2017-09-04
Technical Paper
2017-24-0016
Morris Langwiesner, Christian Krueger, Sebastian Donath, Michael Bargende
Abstract The real cycle simulation is an important tool to predict the engine efficiency. To evaluate Extended Expansion SI-engines with a multi-link cranktrain, the challenge is to consider all concept specific effects as best as possible by using appropriate submodels. Due to the multi-link cranktrain, the choice of a suitable heat transfer model is of great importance since the cranktrain kinematics is changed. Therefore, the usage of the mean piston speed to calculate a heat-transfer-related velocity for heat transfer equations is not sufficient. The heat transfer equation according to Bargende combines for its calculation the actual piston speed with a simplified k-ε model. In this paper it is assessed, whether the Bargende model is valid for Extended Expansion engines. Therefore a single-cylinder engine is equipped with fast-response surface-thermocouples in the cylinder head. The surface heat flux is calculated by solving the unsteady heat conduction equation.
2017-09-04
Technical Paper
2017-24-0019
Alexander Mason, Aaron W. Costall, John R. McDonald
Abstract Mandated pollutant emission levels are shifting light-duty vehicles towards hybrid and electric powertrains. Heavy-duty applications, on the other hand, will continue to rely on internal combustion engines for the foreseeable future. Hence there remain clear environmental and economic reasons to further decrease IC engine emissions. Turbocharged diesels are the mainstay prime mover for heavy-duty vehicles and industrial machines, and transient performance is integral to maximizing productivity, while minimizing work cycle fuel consumption and CO2 emissions. 1D engine simulation tools are commonplace for “virtual” performance development, saving time and cost, and enabling product and emissions legislation cycles to be met. A known limitation however, is the predictive capability of the turbocharger turbine sub-model in these tools.
2017-09-04
Technical Paper
2017-24-0018
Nikiforos Zacharof, Georgios Fontaras, Theodoros Grigoratos, Biagio Ciuffo, Dimitrios Savvidis, Oscar Delgado, J. Felipe Rodriguez
Abstract Heavy-duty vehicles (HDVs) account for some 5% of the EU’s total greenhouse gas emissions. They present a variety of possible configurations that are deployed depending on the intended use. This variety makes the quantification of their CO2 emissions and fuel consumption difficult. For this reason, the European Commission has adopted a simulation-based approach for the certification of CO2 emissions and fuel consumption of HDVs in Europe; the VECTO simulation software has been developed as the official tool for the purpose. The current study investigates the impact of various technologies on the CO2 emissions of European trucks through vehicle simulations performed in VECTO. The chosen vehicles represent average 2015 vehicles and comprised of two rigid trucks (Class 2 and 4) and a tractor-trailer (Class 5), which were simulated under their reference configurations and official driving cycles.
2017-08-25
Technical Paper
2017-01-7000
J. Marcos Garcia de la Cruz, Rowan D. Brackston, Jonathan F. Morrison
Abstract Road vehicles usually operate within windy environments. The combination of typical wind distributions and vehicle speeds, imposes on such vehicles aerodynamic yaw angles, β, which are often almost uniform up to 6° and relevant up to 14°. Drag saving devices are often optimized for zero cross-wind scenarios, minimizing drag only around these design conditions. This work presents the drag saving increase that an adaptive system can provide over a classic boat-tail. In the experimental set up employed, two flaps are located at the rear lateral edges of an Ahmed body and respectively set at angles θ1 and θ2 with respect to the model. To evaluate the efficacy of different flap positioning strategies under cross-wind, the model was tested in a wind tunnel, , with and without flaps at yaw angles β = 0°, 3°, 6° or 9°. The flap sizes tested, δ, were 9% or 13% of the body width. For each β and δ, the maps of drag against the two flap angles were obtained.
2017-08-25
Technical Paper
2017-01-7001
Johannes Haff, Mattias Jönsson, Sigfried Loose, Claus Wagner
Abstract The improved performance of heavy-duty vehicles as transport carriers is essential for economic reasons and to fulfil new emission standards in Europe. A key parameter is the aerodynamic vehicle drag. An enormous potential still exists for fuel saving and reducing exhaust emission by aerodynamic optimisation. Engineering methods are required for developments in vehicle aerodynamics. To assess the reliability of the most common experimental testing and numerical simulation methods in the industrial design process is the objective of this article. Road tests have been performed to provide realistic results, which are compared to the results obtained by scale-model wind tunnel experiments and time-averaged computational fluid dynamics (CFD). These engineering methods are evaluated regarding their deployment in the industrial development process. The investigations focus on the separated flow region behind the vehicle rear end.
2017-08-18
Journal Article
2017-01-9380
Jan-Hubert Wittmann, Lars Menger
Abstract Current regulatory developments aim for stricter emission limits, increased environmental protection and purification of air on a local and global scale. In order to find solutions for a cleaner combustion process, it is necessary to identify the critical components and parameters responsible for the formation of emissions. This work provides an evaluation process for particle formation during combustion of a modern direct injection engine, which can help to create new aftertreatment techniques, such as a gasoline particle filter (GPF) system, that are fit for purpose. With the advent of “real driving emission” (RDE) regulations, which include market fuels for the particulate number testing procedure, the chemical composition and overall quality of the fuel cannot be neglected in order to yield a comparable emission test within the EU and worldwide.
2017-08-17
Journal Article
2017-01-9683
Rui Ma, John B. Ferris, Alexander A. Reid, David J. Gorsich
Abstract Computationally efficient tire models are needed to meet the timing and accuracy demands of the iterative vehicle design process. Axisymmetric, circumferentially isotropic, planar, discretized models defined by their quasi-static constraint modes have been proposed that are parameterized by a single stiffness parameter and two shape parameters. These models predict the deformed shape independently from the overall tire stiffness and the forces acting on the tire, but the parameterization of these models is not well defined. This work develops an admissible domain of the shape parameters based on the deformation limitations of a physical tire, such that the tire stiffness properties cannot be negative, the deformed shape of the tire under quasi-static loading cannot be dominated by a single harmonic, and the low spatial frequency components must contribute more than higher frequency components to the overall tire shape.
2017-08-01
Journal Article
2017-01-9682
Mohsen Rahmani, Kamran Behdinan
Abstract Widely used in automotive industry, lightweight metallic structures are a key contributor to fuel efficiency and reduced emissions of vehicles. Lightweight structures are traditionally designed through employing the material distribution techniques sequentially. This approach often leads to non-optimal designs due to constricting the design space in each step of the design procedure. The current study presents a novel Multidisciplinary Design Optimization (MDO) framework developed to address this issue. Topology, topography, and gauge optimization techniques are employed in the development of design modules and Particle Swarm Optimization (PSO) algorithm is linked to the MDO framework to ensure efficient searching in large design spaces often encountered in automotive applications. The developed framework is then further tailored to the design of an automotive Cross-Car Beam (CCB) assembly.
2017-07-10
Technical Paper
2017-28-1958
Jyothivel Giridharan, Gokul Kumar
Bio-fuels potentially represent a more environmentally friendly alternative to fossil fuels as they produce fewer greenhouse gas emissions when burned. Ethanol is one such bio-fuel alternative to the conventional fossil fuels. Towards the initiative of sustainable transportation using alternative fuels, it is attempted to develop an ethanol powered engine for commercial vehicles and this paper attempts to explain the 1D thermodynamic simulation carried out for predicting the engine performance and combustion characteristics, as a part of the engine development program. Engine simulation is becoming an increasingly important engineering tool for reducing the development cost and time and also helps in carrying out various DOE iterations which are rather difficult to be conducted experimentally in any internal combustion engine development program. AVL Boost software is used for modeling and simulation.
2017-07-10
Technical Paper
2017-28-1953
Tushar Narendra Puri lng, Lalitkumar Ramujagir Soni lng, Sourabh Deshpande
Abstract The infliction of rigorous emission norms across the world has made the automobile industry to focus and dwell upon researches to reduce the emissions from internal combustion engines, namely diesel engines. Variation in fuel injection timing has better influence on reduction of engine exhaust emissions. This papers deals with the variation of fuel injection timing along with fuel injection pressure numerically on a 4 stroke, single cylinder, and direct injection diesel engine running at full load condition using CONVERGE CFD tool. As the piston and bowl geometry considered in this work is symmetric, only 60 degree sector of the piston cylinder assembly is considered for numerical simulation over complete 360 degree model.
2017-07-10
Technical Paper
2017-28-1954
Premkumarr Santhanamm, K. Sreejith, Avinash Anandan
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.
Viewing 271 to 300 of 33500