Characterization of the system behaviour of a variable compression ratio (VCR) connecting rod with eccentrically piston pin suspension and hydraulic moment support

2020 ◽  
Vol 213 ◽  
pp. 112814
Author(s):  
Karsten Wittek ◽  
Frank Geiger ◽  
Marilia G. Justino Vaz
Keyword(s):  
Compression Ratio ◽  
Connecting Rod ◽  
Variable Compression Ratio ◽  
System Behaviour ◽  
Variable Compression

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.

Variable compression ratio engine: A future power plant for automobiles - an overview

2007 ◽  
Vol 221 (9) ◽  
pp. 1159-1168 ◽  
Author(s):  
Amjad Shaik ◽  
N Shenbaga Vinayaga Moorthi ◽  
R Rudramoorthy
Keyword(s):  
Compression Ratio ◽  
Fuel Economy ◽  
Technology Development ◽  
Connecting Rod ◽  
Variable Compression Ratio ◽  
Chamber Volume ◽  
Consumption Benefit ◽  
Si Engines ◽  
Variable Valve ◽  
Variable Compression

Increasingly stringent emissions and fuel economy standards have long remained a source of challenges for research in automobile engine technology development towards the more thermally efficient and less polluting engine. Spark ignition (SI) engines have lower part-load efficiency when compared with the diesel engines. The greatest opportunity for improving SI engine efficiency is by way of higher compression ratio, variable valve timing, low friction, reducing throttling losses, boosting, and down-sizing. Variable compression ratio (VCR) technology has long been recognized as a method for improving the fuel economy of SI engines. In order to vary the compression ratio, some method of varying the geometric compression ratio through changing the clearance volume is required. There are several ways of doing this; various patents have been filed and designs presented, including modification of the compression ratio by moving the cylinder head, variation of combustion chamber volume using a secondary piston or valve, variation of piston deck height, modification of connecting rod geometry, moving the crankpin within the crankshaft, and moving the crankshaft axis. The potential of these technologies needs to be evaluated by a trade-off between cost and consumption benefit. This paper reviews the geometric approaches and solutions used to achieve VCR, considers the results of prior research, and forecasts what benefits, if any, a VCR would bring to present engine design.

Variable Compression Ratio by Means of a Modular System with a Two-stage Switchable Connecting Rod Length

MTZ worldwide ◽  
2018 ◽  
Vol 79 (6) ◽  
pp. 40-45
Author(s):  
Wolfgang Schöffmann ◽  
Helfried Sorger ◽  
Siegfried Lösch ◽  
Kai Arens
Keyword(s):  
Compression Ratio ◽  
Modular System ◽  
Connecting Rod ◽  
Two Stage ◽  
Variable Compression Ratio ◽  
Variable Compression

Coupled Dynamic Simulation of Two Stage Variable Compression Ratio (VCR) Connecting Rod Using Virtual Dynamics

2019 ◽  
Author(s):  
Prashant Mane ◽  
Denis Pendovski ◽  
Sebastian Sonnen ◽  
Alexander Uhlmann ◽  
Daniel Henaux ◽  
...  
Keyword(s):  
Dynamic Simulation ◽  
Compression Ratio ◽  
Connecting Rod ◽  
Two Stage ◽  
Variable Compression Ratio ◽  
Variable Compression
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