scholarly journals Determination of Combustion Process Model Parameters in Diesel Engine with Variable Compression Ratio

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Saša Milojević ◽  
Radivoje Pešić
Keyword(s):  
Diesel Engine ◽  
Compression Ratio ◽  
Process Model ◽  
Internal Combustion Engines ◽  
Combustion Process ◽  
Exhaust Emission ◽  
Model Parameters ◽  
Connecting Rod ◽  
Variable Compression Ratio ◽  
Variable Compression

Compression ratio has very important influence on fuel economy, emission, and other performances of internal combustion engines. Application of variable compression ratio in diesel engines has a number of benefits, such as limiting maximal in cylinder pressure and extended field of the optimal operating regime to the prime requirements: consumption, power, emission, noise, and multifuel capability. The manuscript presents also the patented mechanism for automatic change engine compression ratio with two-piece connecting rod. Beside experimental research, modeling of combustion process of diesel engine with direct injection has been performed. The basic problem, selection of the parameters in double Vibe function used for modeling the diesel engine combustion process, also performed for different compression ratio values. The optimal compression ratio value was defined regarding minimal fuel consumption and exhaust emission. For this purpose the test bench in the Laboratory for Engines of the Faculty of Engineering, University of Kragujevac, is brought into operation.

A Theoretical Study of a Variable Compression Ratio Turbocharged Diesel Engine

1992 ◽  
Vol 206 (4) ◽  
pp. 227-238 ◽  
Author(s):  
T J Rychter ◽  
A Teodorczyk ◽  
C R Stone ◽  
H J Leonard ◽  
N Ladommatos ◽  
...  
Keyword(s):  
Diesel Engine ◽  
Compression Ratio ◽  
Engine Performance ◽  
Expansion Ratio ◽  
Combustion Noise ◽  
Connecting Rod ◽  
Turbocharged Diesel Engine ◽  
Variable Compression Ratio ◽  
Engine Simulation ◽  
Variable Compression

A variable compression ratio concept that can give a different expansion ratio to the compression ratio has been evaluated by means of a simulation of a turbocharged diesel engine. The compression ratio is controlled by varying the ratio of the connecting rod length to the crank throw, hence the name variable crank radius/connecting rod length engine (VR/LE). The VR/LE mechanism kinematics have been defined and described, and the compression ratio and expansion ratio have been presented as a function of the eccentric phase angle (αo). A zero-dimensional engine simulation that has been the subject of comprehensive validation has been used as the basis of the VR/LE study. The effect of the compression ratio on the engine performance at fixed loads is presented. The principal benefits are a reduction in fuel consumption at part load of about 2 per cent and a reduction in ignition delay that leads to an estimated 6 dB reduction in combustion noise. The study has been conducted within the assumption of a maximum cylinder pressure of 160 bar.

A comprehensive evaluation of water injection in the diesel engine

2021 ◽  
pp. 146808742110442
Author(s):  
Sebastian Welscher ◽  
Mohammad Hossein Moradi ◽  
Antonino Vacca ◽  
Peter Bloch ◽  
Michael Grill ◽  
...  
Keyword(s):  
Diesel Engine ◽  
Internal Combustion Engines ◽  
Comprehensive Evaluation ◽  
Combustion Engine ◽  
Water Injection ◽  
Combustion Process ◽  
Internal Combustion ◽  
Exhaust Emission ◽  
Pressure Trace ◽  
High Level

Due to increasing climate awareness and the introduction of much stricter exhaust emission legislation the internal combustion engine technology faces major challenges. Although the development and state of technology of internal combustion engines generally reached a very high level over the last years those need to be improved even more. Combining water injection with a diesel engine, therefore, seems to be the next logical step in developing a highly efficient drive train for future mobility. To investigate these potentials, a comprehensive evaluation of water injection on the diesel engine was carried out. This study covers >560 individual operating points on the test bench. The tests were carried out on a single-cylinder derived from a Euro 6d four-cylinder passenger car with the port water injection. Furthermore, a detailed pressure trace analysis (PTA) was performed to evaluate various aspects regarding combustion, emission, etc. The results show no significant effects of water injection on the combustion process, but great potential for NOx reduction. It has been shown that with the use of water injection at water-to-fuel rates of 25%, 50%, and 100%, NOx reduction without deterioration of soot levels can be achieved in 62%, 40%, and 20% of the experiments, respectively. Furthermore, water injection in combination with EGR offers additional reduction in NOx emissions.

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