International Scientific Journal


The compression ratio strongly affects the working process and provides an exceptional degree of control over engine performance. In conventional internal combustion engines, the compression ratio is fixed and their performance is therefore a compromise between conflicting requirements. One fundamental problem is that drive units in the vehicles must successfully operate at variable speeds and loads and in different ambient conditions. If a diesel engine has a fixed compression ratio, a minimal value must be chosen that can achieve a reliable self-ignition when starting the engine in cold start conditions. In diesel engines, variable compression ratio provides control of peak cylinder pressure, improves cold start ability and low load operation, enabling the multi-fuel capability, increase of fuel economy and reduction of emissions. This paper contains both theoretical and experimental investigation of the impact that automatic variable compression ratios has on working process parameters in experimental diesel engine. Alternative methods of implementing variable compression ratio are illustrated and critically examined.
PAPER REVISED: 2010-07-21
PAPER ACCEPTED: 2010-07-24
CITATION EXPORT: view in browser or download as text file
  1. Pešić, R., Automobile SI Engines with Minimal Fuel Consumption, Monographic Issue of Journal Mobility & Vehicle Mechanics, Kragujevac, Serbia, 1994
  2. Milojevic, S., Analyzing the Impact of Variable Compression Ratio on Combustion Process in Diesel Engines, M. Sc. thesis, Faculty of Mechanical Engineering, University of Kragujevac, Kragujevac, Serbia, 2005
  3. Walter, B., Gatellier, B., Near Zero NOx Emissions and High Fuel Efficiency Diesel Engine: the NADITM Concept Using Dual Mode Combustion, Oil & Gas Science and Technology, Rev. IFP, 58 (2003), 1, pp. 101-114
  4. Gruden, D., Environmental Protection in the Automotive Industry (in German), Vieweg + Teubner Verlag, GmbH, Wiesbaden, Germany, 2008
  5. Stegemann, J., et. al., Injection System for Fully Variable Control of the Shape (in German), MTZ, 65 (2004), 2, pp. 114-121
  6. Yoshihiro, H., Minaji, I., Kiyomi, N., Achieving Lower Exhaust Emission and Better Performance in an HSDI Diesel Engine with Multiple Injection, R&D Review of Toyota CRDL, 37 (2002), 3, pp. 9-16
  7. Friedl, K. G., Herzog, P., Otto & Diesel Engines Perspectives for the Future (in German), Proceedings, 16th International AVL Conference Engine & Environment, Graz, Austria, 2004, pp. 91-112
  8. Erlandsson, et. al., Demonstrating the Performance and Emission Characteristics of a Variable Compression Ratio, Alvar-Cycle Engine, SAE paper 982682, Presented at the International Fall Fuels and Lubricants Meeting and Exposition, San Francisco, Cal., USA, 1998
  9. Bergsten, L., SAAB Variable Compression SVC - Variability and Control (in German), MTZ, 62 (2001), 6, pp. 424-431
  10. Schwaderlapp, M., Habermann, K., Yapici, K., Variable Compression Ratio - A Design Solution for Fuel Economy Concepts, SAE technical paper 2002-01-1103, 1760-1767, 2002, pp. 1-10
  11. Pischinger, S., et. al., On the Road Consequent Downsizing Engine with Continuously Variable Compression Ratio in a Demonstration Vehicle (in German), MTZ, 64 (2003), 5, pp. 398-405
  12. Brevick, J., Howden, K., Design and Development of a Pressure Reactive Piston (PRP) to Achieve Variable Compression Ratio, USA DOE Progress Report for Combustion and Emission Control for Advanced CIDI Engines (Ed. G. Singh), U. S. Department of Energy, S. W. Washington, FY 2002, pp. 154-159
  13. Pešić, R., Davinić, A., Veinović, S., New Engine Method for Biodiesel Cetane Number Testing, Thermal Science, 12 (2008), 1, pp. 125-138
  14. Pešić, R., Davinić, A., Veinović, S., One Engine for all Fuels - One Fuel for all Engines - EAEC05YU-EN01, Proceedings (Ed. Č. Duboka), 10th EAEC European Automotive Congress, Belgrade, 2005, pp. 1-10
  15. Tomić, M., et al., A Quick, Simplified Approach to the Evaluation of Combustion Rate from an Internal Combustion Engine Indicator Diagram, Thermal Science, 12 (2008), 1, pp. 85-102
  16. Pischinger, R., Krassnig, G., Glaser, J., Problems of Pressure Indication in Internal Combustion Engines, Proceedings, International Symposium on Diagnostics and Modelling of Combustion in Reciprocating Engines, JSME, SAEJ, MESJ, COMODIA 1985, Tokyo, 1985, pp. 539-549
  17. Sobotowski, R., Porter, C. B., Pilley, D. A., The Development of a Novel Variable Compression Ratio, Direct Injection Diesel Engine, SAE technical paper 910484, International Congress and Exposition, Detroit, Mich., USA, 1991
  18. Jafarmadar, S., et al., Modelling the Effect of Spray/Wall Impingement on Combustion Process and Emission of DI-Diesel Engine, Thermal Science, 13 (2009), 3, pp. 23-34
  19. Boussouara, K., Kadja, M., Empirical Soot Formation and Oxidation Model, Thermal Science, 13 (2009), 3, pp. 35-46
  20. Ranjbar, A. A., et al., Computational Study of the Effect of Different Injection Angle on Heavy-Duty Diesel Engine Combustion, Thermal Science, 13 (2009), 3, pp. 9-21

© 2018 Society of Thermal Engineers of Serbia. Published by the Vinča Institute of Nuclear Sciences, Belgrade, Serbia. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International licence