scholarly journals Flow resistance in the engine inlet-exhaust system as affected by the engine parameters

2009 ◽  
Vol 136 (1) ◽  
pp. 31-40
Author(s):  
Zbigniew ŻMUDKA ◽  
Stefan POSTRZEDNIK

The paper presents theoretical and experimanetal research into the process of charge exchange in a spark ignition engine (the process of cylinder filling and discharging). A significant role in the inlet system plays the resistance of the flow of a fresh charge through the throttle, particularly when its partially opened. In classic spark ignition engine solutions this flow resistance is a part of the engine load imposition. The problem has been illustrated by the theoretical and experimental test results of the influence of the pressure drop Δpd on the side of the fresh charge flow and the pressure drop Δpw in the exhaust system on the engine operation. Relations have been determined between the engine operating parameters and the flow conditions of the charge/exhaust gases.

2014 ◽  
Vol 35 (3) ◽  
pp. 191-205 ◽  
Author(s):  
Zbigniew Żmudka ◽  
Stefan Postrzednik ◽  
Grzegorz Przybyła

Abstract The theoretical analysis of the charge exchange process in a spark ignition engine has been presented. This process has significant impact on the effectiveness of engine operation because it is related to the necessity of overcoming the flow resistance, followed by the necessity of doing a work, so-called the charge exchange work. The flow resistance caused by the throttling valve is especially high during the part load operation. The open Atkinson-Miller cycle has been assumed as a model of processes taking place in the engine. Using fully variable inlet valve timing the A-M cycle can be realized according to two systems: system with late inlet valve closing and system with early inlet valve closing. The systems have been analysed individually and comparatively with the open Seiliger-Sabathe cycle which is a theoretical cycle for the classical throttle governing of the engine load. Benefits resulting from application of the systems with independent inlet valve control have been assessed on the basis of the selected parameters: fuel dose, cycle work, charge exchange work and a cycle efficiency. The use of the analysed systems to governing of the SI engine load will enable to eliminate a throttling valve from the system inlet and reduce the charge exchange work, especially within the range of part load operation.


2018 ◽  
Vol 19 (6) ◽  
pp. 463-467
Author(s):  
Krystian Hennek ◽  
Mariusz Graba

Paper discussed the influence of exhaust system leakage on the utility parameters and toxic combustion products emission of a turbocharged passenger car spark ignition engine. A comparative analysis of the data gathered in the research carried out using the MAHA MSR 500 single roller chassis dynamometer was conducted, where the exhaust system was sealed and leaking in the area of the wideband oxygen sensor mounting bracket. The presented data refers to among others: the emissions of harmful gasoline oxidation products (HC, CO), the courses of power generated by the engine and the momentary values of excess air ratio. The EUDC driving cycle was used in the research.


Author(s):  
Michael Marr ◽  
James S. Wallace ◽  
Larry Pershin ◽  
Sanjeev Chandra ◽  
Javad Mostaghimi

A novel metal-based thermal barrier coating was tested in a spark-ignition engine. The coating was applied to the surface of aluminum plugs and exposed to in-cylinder conditions through ports in the cylinder wall. Temperatures were measured directly behind the coating and within the plug 3 and 11 mm from the surface. In-cylinder pressures were measured and analyzed to identify and quantify knock. Test results suggest the coating does not significantly reduce overall heat transfer, but it does reduce the magnitude of temperature fluctuations at the substrate surface. It was found that heat transfer can be reduced by reducing the surface roughness of the coating. The presence of the coating did not promote knock.


2017 ◽  
Vol 38 (4) ◽  
pp. 15-28 ◽  
Author(s):  
Małgorzata Sikora ◽  
Tadeusz Bohdal

Abstract Investigations of refrigerant condensation in pipe minichannels are very challenging and complicated issue. Due to the multitude of influences very important is mathematical and computer modeling. Its allows for performing calculations for many different refrigerants under different flow conditions. A large number of experimental results published in the literature allows for experimental verification of correctness of the models. In this work is presented a mathematical model for calculation of flow resistance during condensation of refrigerants in the pipe minichannel. The model was developed in environment based on conservation equations. The results of calculations were verified by authors own experimental investigations results.


1975 ◽  
Vol 189 (1) ◽  
pp. 139-147 ◽  
Author(s):  
G. A. Karim ◽  
I. A. Ali

For various fuel-air mixtures and different compression ratios, the intake temperature was varied over the entire range of ***200°F (366K) down to − 100°F (200K) when employing a single cylinder spark ignited research engine fuelled with natural gas. Performance data such as knock and ignition limits the nature and extent of exhaust emission and chamber pressure cyclic variation were obtained. Means were then suggested for the interpretation of the above mentioned data in terms of engine operation on liquefied natural gas. The experimental work confirmed in general the attractive features of the use of natural gas as a fuel in a spark ignition engine operated under extremely cold intake temperature conditions and that emissions of pollutants were not significantly increased.


Author(s):  
Christopher Cooney ◽  
Thomas Wallner ◽  
Steve McConnell ◽  
Jeffrey C. Gillen ◽  
Clint Abell ◽  
...  

The new U.S. Renewable Fuel Standard requires an increase of ethanol and advanced biofuels to 36 billion gallons by 2022. Due to its high octane number, renewable character and minimal toxicity, ethanol was believed to be one of the most favorable alternative fuels to displace gasoline in spark-ignited engines. However, ethanol fuel results in a substantial reduction in vehicle range when compared to gasoline. In addition, ethanol is fully miscible in water which requires blending at distribution sites instead of the refinery. Butanol, on the other hand, has an energy density comparable to gasoline and lower affinity for water than ethanol. Butanol has recently received increased attention due to its favorable fuel properties as well as new developments in production processes. The advantageous properties of butanol warrant a more in-depth study on the potential for butanol to become a significant component of the advanced biofuels mandate. This study evaluates the combustion behavior, performance, as well as the regulated engine-out emissions of ethanol and butanol blends with gasoline. Two of the butanol isomers; 1-butanol as well as iso-butanol, were tested as part of this study. The evaluation includes gasoline as a baseline, as well as various ethanol/gasoline and butanol/gasoline blends up to a volume blend ratio of 85% of the oxygenated fuel. The test engine is a spark ignition, direct-injection, (SIDI), four-cylinder test engine equipped with pressure transducers in each cylinder. These tests were designed to evaluate a scenario in terms of using these alcohol blends in an engine calibrated for pump gasoline operation. Therefore no modifications to the engine calibration were performed. Following this analysis of combustion behavior and emissions with the base engine calibration, future studies will include detailed heat release analysis of engine operation without exhaust gas recirculation. Also, knock behavior of the different fuel blends will be studied along with unregulated engine out emissions.


Author(s):  
Michael A. Marr ◽  
James S. Wallace ◽  
Larry Pershin ◽  
Sanjeev Chandra ◽  
Javad Mostaghimi

A novel metal-based thermal barrier coating was tested in a spark-ignition engine. The coating was applied to the surface of aluminum plugs and exposed to in-cylinder conditions through ports in the cylinder wall. Temperatures were measured directly behind the coating and within the plug 3 and 11 mm from the surface. In-cylinder pressures were measured and analyzed to identify and quantify knock. Test results suggest the coating does not significantly reduce overall heat transfer, but it does reduce the magnitude of temperature fluctuations at the substrate surface. It was found that heat transfer can be reduced by reducing the surface roughness of the coating. The presence of the coating did not promote knock.


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