This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
Combustion Simulations for a Self Controlling Variable Compression Ratio Connecting Rod
Technical Paper
2012-01-1154
ISSN: 0148-7191, e-ISSN: 2688-3627
Annotation ability available
Sector:
Language:
English
Abstract
Variable compression ratio enables an engine to achieve
increased efficiency at part loads, where the majority of driving
occurs, without sacrificing full load power requirements or
increasing the risk of engine knock. Although over 100 patents and
patent applications exist none of these systems has been
commercialized yet due to issues related to feasibility, cost and
frictional loss.
A new approach of a self-controlling variable compression ratio
connecting rod is presented that does not need a friction intensive
external activation and that could even be retrofitted.
The potential in fuel consumption and exhaust emission reduction
as well as increased power and torque output for this concept has
been verified in combustion simulations utilizing the latest
research results related to the dynamic heat transfer in the
combustion chamber from Professor Kleinschmidt from the University
of Siegen, Germany.
The self-controlling variable compression ratio connecting rod
allows the con rod to compress at high load conditions thereby
increasing cylinder volume to alleviate combustion pressures and
temperatures and therefore limit knock onset. The biggest
efficiency gains can be achieved at medium load where the reduction
of heat loss during the compression of the connecting rod plays a
major role additional to the well known efficiency gains of an
increased compression ratio.
The combustion simulation results shows fuel consumption can be
reduced by between 3% and 5% during part load and wide open
throttle operation at various engine speeds. Emissions are also
reduced significantly; particularly NOx and CO emissions
were reduced by up to 35%.
Topic
Citation
Will, F. and Mayson, D., "Combustion Simulations for a Self Controlling Variable Compression Ratio Connecting Rod," SAE Technical Paper 2012-01-1154, 2012, https://doi.org/10.4271/2012-01-1154.Also In
References
- Assanis, D. Cho, W. Choi, I. Ickes, A. et al. “Pressure Reactive Piston Technology Investigation and Development for Spark Ignition Engines,” SAE Technical Paper 2005-01-1648 2005 10.4271/2005-01-1648
- Kehn, U Bargende, U 2003 Variables Epsilon - Mittel zur Wirkungsgraderhoehung bei hochaufgeladenen Ottomotoren Stuttgarter Motorensymposium 18 20 February 2003 German
- Kehn, U 2007 Variables Epsilon - Mittel zur Wirkungsgraderhoehung bei hochaufgeladenen Ottomotoren Expert Verlag Renningen, Germany (German)
- Kleinschmidt, W Hebel, D. Instationaere Waermeuebertragung in Verbrennungsmotoren - Theory Simulation and comparison with Test Results, final report of research project Kl600/1-2 German Research Association 1995 German
- Kleinschmidt, W Hebel, D. Instationaere Waermeuebertragung in Verbrennungsmotoren - Theory, Simulation and comparison with Test Results VDI Progress Reports, No 383 Society of German Engineers (VDI) 1999 German
- Huber, K 1990 Der Waermeuebergang schnelllaufender, dierkteinspritzender Sieselmotoren Dissertation TU Munich German
- Woschni, G et al. Isolierung der Brennraumwaende - Ein lohnendes Ziel bei Verbrennungsmotoren ? MTZ 47 1986 12 495 500
- Mavropoulos, G. Rakopoulos, C. Hountalas, D. “Experimental Assessment of Instantaneous Heat Transfer in the Combustion Chamber and Exhaust Manifold Walls of Air-Cooled Direct Injection Diesel Engine,” SAE Int. J. Engines 1 1 888 912 2009 10.4271/2008-01-1326
- Garcia, M G. 2009 A new heat release rate (HRR) law for homogeneous charge compression ignition (HCCI) combustion mode Applied Thermal Engineering 29 2009 3654 3662
- Lejsek, D. Kulzer, A. “Investigations on the Transient Wall Heat Transfer at Start-Up for SI Engines with Gasoline Direct Injection,” SAE Int. J. Engines 2 1 381 397 2009 10.4271/2009-01-0613
- Lejsek, D et al. 2010 Calculation of the Wall Heat Transfer during Start-Up of SISI Engines MTZ 04 2010 71 23 29
- Demuynck, J et al. 2010 Heat transfer measurements inside gas fuelled spar ignited engine for model validation, F2010-A-062 FISITA congress Budapest
- Aoki, Y et al. 2010 An experimental study on heat transfer coefficient of all combustion chamber wall surfaces in a naturally aspirated D.I. Diesel engine F2010-A-151, FISITA congress Budapest
- Kleinschmidt, W 2000 Zur Simulation des Betriebs von Ottomotoren an der Klopfgrenze Fortschritt-Berichte VDI, Reihe 12 No. 422 Society of German Engineers (VDI) 1999 German
- Van Basshuysen, R. Schaefer, F. “Internal Combustion Engine Handbook: Basics, Components, Systems, and Perspectives,” Society of Automotive Engineers, Inc. Warrendale, PA 978-0-7680-1139-5 2004 10.4271/R-345