The Experts below are selected from a list of 324 Experts worldwide ranked by ideXlab platform
D. T. Hountalas - One of the best experts on this subject based on the ideXlab platform.
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Development and validation of a new turbocharger simulation methodology for marine two stroke diesel engine modelling and diagnostic applications
Energy, 2015Co-Authors: Nikolaos F. Sakellaridis, Spyridon I. Raptotasios, Antonis K. Antonopoulos, G C Mavropoulos, D. T. HountalasAbstract:Engine cycle simulation models are increasingly used in diesel engine simulation and diagnostic applications, reducing experimental effort. Turbocharger simulation plays an important role in model's ability to accurately predict engine performance and emissions. The present work describes the development of a complete engine simulation model for marine Diesel engines based on a new methodology for turbocharger modelling utilizing physically based meanline models for compressor and turbine. Simulation accuracy is evaluated against engine bench measurements. The methodology was developed to overcome the problem of limited experimental maps availability for compressor and turbine, often encountered in large marine diesel engine simulation and diagnostic studies. Data from the engine bench are used to calibrate the models, as well as to estimate turbocharger shaft mechanical efficiency. Closed cycle and gas exchange are modelled using an existing multizone thermodynamic model. The proposed methodology is applied on a 2-stroke marine diesel engine and its evaluation is based on the comparison of predictions against measured engine data. It is demonstrated model's ability to predict engine response with load variation regarding both turbocharger performance and closed cycle parameters, as well as NOx emission trends, making it an effective tool for both engine diagnostic and optimization studies.
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Prediction of marine diesel engine performance under fault conditions
Applied Thermal Engineering, 2000Co-Authors: D. T. HountalasAbstract:The diesel engine, due to its superior efficiency when compared to other thermal engines, is widely used for propulsion of marine vessels. Since in such applications the power concentration is critical, most marine diesel engines are of the turbocharged type. Turbocharging has a serious effect on engine performance due to the interaction between the turbocharger and the engine. This interaction makes the detection of engine faults extremely difficult since a specific fault affects the turbocharger and through it the engine. For this reason various methods have been proposed for the detection of engine faults. The present author has in the past presented a method for marine diesel diagnosis by processing measured engine data using a simulation model. In the present work a completely different approach is followed; an attempt is made to use a simulation model to predict marine diesel engine performance under various fault conditions. The method is applied to a newly built vessel powered by a slow speed two stroke marine diesel engine. Using the engine shop trial data obtained under propeller law the simulation model constants are determined, using an automatic method that has been developed. The comparison of results obtained with the data from the official shop trials confirms the accuracy of the model and its ability to predict almost all operating parameters of the engine. The model is then used to produce results by simulating various engine faults or faults of its subsystems. From this analysis their impact on various measurable engine parameters is determined. It is interesting to see that in the case of turbocharged engines some faults have a different effect when compared to naturally aspirated ones. Also, it is revealed that without the use of modeling in many cases it is relatively difficult to determine the actual cause for an engine malfunction, since the observed effects on engine performance are similar. The proposed method is promising and assists the engineer to understand the actual effect of various faults on engine performance. Also it can be used as a training tool since it is easy to simulate various engine faults, a procedure which is extremely difficult, if not impossible, to perform on the field.
D Singh - One of the best experts on this subject based on the ideXlab platform.
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Prediction and Analysis of Engine Friction Power of a Diesel Engine Influenced by Engine Speed, Load, and Lubricant Viscosity
Advances in Tribology, 2014Co-Authors: D Singh, John D. Fieldhouse, Fengshou Gu, N. B. Singh, S.k. SingalAbstract:Automotive industries made a paradigm shift in selection of viscometrics of engine lubricant, from higher to lower viscosity grade, for improving fuel economy of vehicles. Engine fuel consumption is influenced by friction between the various engine components. Engine friction power (FP) of a direct injection diesel engine is calculated from the measured value of in-cylinder pressure signals at various operating conditions. For predicting FP, as a function of speed, load, and lubricant viscosity, a full factorial design of experiments (DOE) was formulated and an empirical correlation was developed. Response surface methodology (RSM) was used for analyzing the dominant parameters and their interactions, which influence engine friction power significantly. Predicted results of engine FP are in good agreement with measured values at all operating points. ANOVA and RSM analysis revealed that the significant parameters influencing engine FP are speed, load, viscosity, speed-load, and speed-viscosity. The effect of engine lubricant viscosity on friction power of a diesel engine was insignificant at low speed, whereas, at high speed, it played a vital role. The empirical relation developed for predicting FP is very useful in estimating engine friction power for various combinations of engine speeds, loads, and lubricant viscosity without running the engine.
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Investigating the Effect of Operating Variables and Engine Lubricant Viscosity on Engine Friction- A DOE Approach
SAE Technical Paper, 2012Co-Authors: D Singh, M R Tyagi, John D. Fieldhouse, Anil K Jain, S.k. SingalAbstract:Engine components are exposed to various lubrication regimes such as hydrodynamic, elasto-hydrodynamic, boundary and mixed lubrication during engine operation. In each of these regimes, the factors which influence engine friction are different. Hydrodynamic friction is influenced by lubricant rheology, film thickness and sliding speed of interacting surfaces, whereas boundary and elasto-hydrodynamic friction is a function of surface properties like roughness and hardness and the type of friction modifier used in engine lubricant. So the principal factors which influence engine friction power are speed, load, surface topography of engine components, oil viscosity, oil temperature and type of friction modifiers used. Experimental studies on an off-highway diesel engine were conducted to investigate the effect of engine oil viscosity and engine operating conditions on engine friction power. A full factorial design of experiments (DOE) was formulated to analyze some of the important parameters by which engine friction power influenced significantly. Three factors; speed, load and oil viscosity were chosen as variables with each factor having two levels. Statistical analysis of the test results revealed that the engine speed and speed-load combination are the most significant factors on which engine friction is strongly influenced. Also it has been observed that there is reduction in engine friction power at high speed when lower viscosity grade engine oil was used instead of the recommended viscosity grade engine oil. Copyright © 2011 SAE International.
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Investigating the Effect of Engine Lubricant Viscosity on Engine Friction and Fuel Economy of a Diesel Engine
2011Co-Authors: D SinghAbstract:Fuel economy is affected, both by fuel and engine lubricant quality. Engine lubricant quality plays a vital role in reduction of fuel consumption by effective reduction of friction between the contact surfaces of engine parts (piston ring assembly, bearings and valve train). Engine components are exposed to various lubrication regimes such as hydrodynamic, elasto-hydrodynamic, boundary and mixed lubrication during engine operation. In each of these regimes, the factors which influence engine friction are different. Hydrodynamic friction is influenced by lubricant rheology, film thickness and sliding speed of interacting surfaces, whereas boundary and elasto-hydrodynamic friction is a function of surface properties like roughness and hardness and the type of friction modifier used in engine lubricant. So the principal factors which influence engine friction power are speed, load, and surface topography of engine components, oil viscosity, oil temperature and type of friction modifiers used. It is generally accepted that both the piston assembly and bearings are predominantly in the hydrodynamic lubrication regime, whereas the valve train is in the mixed/boundary lubrication regime. Hydrodynamic friction is proportional to sliding velocity of a pair, oil film thickness, operating temperature, lubricant viscosity and many other physical parameters. To investigate the effect of engine lubricant viscosity on friction characteristics and fuel consumption of a heavy duty and light duty diesel engine, an experimental study was carried out on a 4-cylinder, Direct Injection off-highway, heavy-duty, diesel engine and 4- cylinder indirect injection, light duty diesel engine coupled with the appropriate eddy current dynamometers and instrumented with fuel consumption measurement unit, pressure sensor, angle encoder, speed sensor, temperature indicators, data acquisition system etc, to measure the fuel consumption, power/torque etc. Two engine lubricants were selected for both types of engine in such a way that both lubricants were of same performance category but having different viscosity grade. For DI diesel engine SAE 20W-50 and SAE 10W-30 engine lubricant complying with API CG-4 were chosen, whereas for IDI diesel engine SAE 15W-40 and SAE 5W-30 engine lubricants complying with API CF-4 were selected. It is to be noted that recommended engine oil was taken as baseline lubricant for the friction and fuel consumption study. Test results in terms of friction mean effective pressure (FMEP), friction power, fuel consumption (g/kWh) were analyzed for DI heavy duty diesel engine for both engine lubricants. Whereas test results in terms of fuel consumption and Fuel Efficiency (%FE) for the light duty IDI diesel engine were analyzed for both engine lubricants. In order to determine the most dominant factor among the engine operating conditions such as speed, load and engine lubricant viscosity, which affect engine friction power significantly, a full factorial design of experiments (DOE) was formulated to analyze some of the important parameters by which engine friction power influenced significantly. Three factors; speed, load and oil viscosity were chosen as variables with each factor having two levels. Statistical analysis for determining the dominant factor, affecting the friction power of an engine revealed that the engine speed and speed-load combination are the most significant factors on which engine friction is strongly influenced. An empirical model was developed based on the selected parameters i.e. speed, load and engine lubricant viscosity for predicting the distribution of possible outcomes (friction power) for the Off-highway, DI diesel engine. It may be seen with this investigation that there is consistent reduction in engine friction power at high speed when lower viscosity grade engine oil was used instead of the recommended viscosity grade engine oil. Hence it may be concluded from the experimental engine study that lower viscosity engine lubricant with the same API performance category levels as of OEMs recommended engine lubricant, used for both DI heavy duty and IDI light duty diesel engine, results in reduction in friction power, fuel consumption and yield better fuel efficiency than the recommended engine lubricant.
Zhiqiang Yuwen - One of the best experts on this subject based on the ideXlab platform.
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Study on engine start-stop control strategy for series-parallel hybrid vehicle
2015 IEEE International Conference on Mechatronics and Automation (ICMA), 2015Co-Authors: Hongyu Wang, Yunqian Qiao, Yong Fang, Zhiming Li, Zhiqiang YuwenAbstract:This paper is aimed to study on engine start-stop control strategy in series-parallel hybrid system. Firstly, working principle of hybrid vehicle is introduced, especially on series-parallel hybrid system and engine start-stop technology. Secondly, control algorithm of engine start-stop is developed; we discuss different transition conditions in engine states. The control algorithm is validated on a hybrid electric vehicle, and test results show that the engine can start or stop rightly when conditions satisfy, and engine also works in the high efficiency area.
S.k. Singal - One of the best experts on this subject based on the ideXlab platform.
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Prediction and Analysis of Engine Friction Power of a Diesel Engine Influenced by Engine Speed, Load, and Lubricant Viscosity
Advances in Tribology, 2014Co-Authors: D Singh, John D. Fieldhouse, Fengshou Gu, N. B. Singh, S.k. SingalAbstract:Automotive industries made a paradigm shift in selection of viscometrics of engine lubricant, from higher to lower viscosity grade, for improving fuel economy of vehicles. Engine fuel consumption is influenced by friction between the various engine components. Engine friction power (FP) of a direct injection diesel engine is calculated from the measured value of in-cylinder pressure signals at various operating conditions. For predicting FP, as a function of speed, load, and lubricant viscosity, a full factorial design of experiments (DOE) was formulated and an empirical correlation was developed. Response surface methodology (RSM) was used for analyzing the dominant parameters and their interactions, which influence engine friction power significantly. Predicted results of engine FP are in good agreement with measured values at all operating points. ANOVA and RSM analysis revealed that the significant parameters influencing engine FP are speed, load, viscosity, speed-load, and speed-viscosity. The effect of engine lubricant viscosity on friction power of a diesel engine was insignificant at low speed, whereas, at high speed, it played a vital role. The empirical relation developed for predicting FP is very useful in estimating engine friction power for various combinations of engine speeds, loads, and lubricant viscosity without running the engine.
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Investigating the Effect of Operating Variables and Engine Lubricant Viscosity on Engine Friction- A DOE Approach
SAE Technical Paper, 2012Co-Authors: D Singh, M R Tyagi, John D. Fieldhouse, Anil K Jain, S.k. SingalAbstract:Engine components are exposed to various lubrication regimes such as hydrodynamic, elasto-hydrodynamic, boundary and mixed lubrication during engine operation. In each of these regimes, the factors which influence engine friction are different. Hydrodynamic friction is influenced by lubricant rheology, film thickness and sliding speed of interacting surfaces, whereas boundary and elasto-hydrodynamic friction is a function of surface properties like roughness and hardness and the type of friction modifier used in engine lubricant. So the principal factors which influence engine friction power are speed, load, surface topography of engine components, oil viscosity, oil temperature and type of friction modifiers used. Experimental studies on an off-highway diesel engine were conducted to investigate the effect of engine oil viscosity and engine operating conditions on engine friction power. A full factorial design of experiments (DOE) was formulated to analyze some of the important parameters by which engine friction power influenced significantly. Three factors; speed, load and oil viscosity were chosen as variables with each factor having two levels. Statistical analysis of the test results revealed that the engine speed and speed-load combination are the most significant factors on which engine friction is strongly influenced. Also it has been observed that there is reduction in engine friction power at high speed when lower viscosity grade engine oil was used instead of the recommended viscosity grade engine oil. Copyright © 2011 SAE International.
Xiaolong Liu - One of the best experts on this subject based on the ideXlab platform.
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Realizing the part load control of a hydrogen-blended gasoline engine at the wide open throttle condition
International Journal of Hydrogen Energy, 2014Co-Authors: Shuofeng Wang, Changwei Ji, Bo Zhang, Xiaolong LiuAbstract:This paper proposed a way for realizing the load control of a hydrogen-blended gasoline engine running at the wide open throttle (WOT) condition through lean combustion. The engine performance of the original gasoline engine and a 3% hydrogen-blended gasoline engine running at the WOT and lean conditions under various loads at a constant engine speed of 1400 rpm was compared. The experimental results showed that because of the reduced residual gas fraction and throttling loss, brake thermal efficiency of the 3% hydrogen-blended gasoline engine running at the WOT and lean conditions was obviously higher than that of the pure gasoline engine. The 3% hydrogen-blended gasoline engine running at the WOT and lean conditions produced much lower particulate and CO emissions than the original gasoline engine. Besides, NOx emissions at part load conditions were also reduced for the 3% hydrogen-blended gasoline engine running at the WOT and lean conditions. © 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.