This content is not included in your SAE MOBILUS subscription, or you are not logged in.
Cylinder Cooling for Improved Durability on an Opposed-Piston Engine
ISSN: 0148-7191, e-ISSN: 2688-3627
Published April 16, 2012 by SAE International in United States
Annotation ability available
The cooling system design for a two-stroke, opposed-piston (OP) engine is substantially different from that of a conventional four-stroke engine as the opposed-piston engine requires efficient cooling at the center of the cylinder where the heat load is highly concentrated. A thermally efficient design ensures engine durability by preserving the oil film at the top ring reversal zone. This is achieved by limiting the surface temperature of the liner to below 270°C at this location. Various water jacket designs have been analyzed with computational fluid dynamics (CFD) using a "discretized" Nusselt number approach for the gas side heat flux prediction. With this method, heat transfer coefficients are computed locally given the flow field of the combustion gases near the liner surface and then multiplied by the local gas/liner temperature difference to generate the heat flux distribution into the cylinder liner. The heat flux is then averaged over the cycle before being applied as a boundary condition to the CFD simulation. The baseline design consists of a simple water jacket with coolant flowing axially from the inlet near the intake port to the outlet near the exhaust port. This approach yields uneven cooling both longitudinally and circumferentially about the cylinder liner. A greatly improved thermal response has been achieved by introducing the coolant at the hot center section of the liner with roughly half of the coolant flowing toward either end of the cylinder. A detailed analysis shows that liner surface temperatures well below 270°C can be achieved for an engine with a power density of 50 kW/liter by carefully optimizing the coolant velocities in the center section of the liner.
CitationLee, P. and Wahl, M., "Cylinder Cooling for Improved Durability on an Opposed-Piston Engine," SAE Technical Paper 2012-01-1215, 2012, https://doi.org/10.4271/2012-01-1215.
- Flint, M.L.S. Pirault, J.-P. “Opposed Piston Engines: Evolution, Use, and Future Applications,” SAE International Warrendale, PA 978-0-7680-1800-4 2009 10.4271/R-378
- Barsanti, E. Matteucci, F. “Motore a Pistoni Contrapposti” Piedmont Patent 700 July 26 1858
- Barsanti, E. Matteucci, F. “Improved Apparatus for Obtaining Motive Power from Explosive Compounds” Great Britain Patent 3270 December 31 1861
- Regner, G. Herold, R. Wahl, M. Dion, E. et al. “The Achates Power Opposed-Piston Two-Stroke Engine: Performance and Emissions Results in a Medium-Duty Application,” SAE Int. J. Engines 4 3 2726 2735 2011 10.4271/2011-01-2221
- Junkers, H. “Cylinder of Internal-Combustion Engines and Other Similar Machines” U.S. Patent 1 231 903 July 3 1917
- Junkers, H. “Engine” U.S. Patent 2 031 318 February 18 1936
- Dent, J. Sulaiman, S. “Convective and Radiative Heat Transfer in a High Swirl Direct Injection Diesel Engine,” SAE Technical Paper 770407 1977 10.4271/770407
- Kreith, F. “Principles of Heat Transfer” 2 nd International Textbook Co. Scranton 1969 314
- Annand, W.J.D. “Heat Transfer in the Cylinders of Reciprocating Internal Combustion Engines” Proc. Inst. Mech. Engrs. 177 36 1963 973
- Woschni, G. “A Universally Applicable Equation for the Instantaneous Heat Transfer Coefficient in the Internal Combustion Engine,” SAE Technical Paper 670931 1967 10.4271/670931
- LeFeuvre, T. Myers, P. Uyehara, O. “Experimental Instantaneous Heat Fluxes in a Diesel Engine and Their Correlation,” SAE Technical Paper 690464 1969 10.4271/690464
- White, F. “Heat and Mass Transfer” Addison-Wesley Publishing Company, Inc. 1991 324
- Society of Fire Protection Engineers “SFPE Handbook of Fire Protection Engineering” National Fire Protection Association 2nd 1995
- Sher, E. “Modeling the Scavenging Process in the Two-Stroke Engine-An Overview,” SAE Technical Paper 890414 1989 10.4271/890414
- Merker, G. Gerstle, M. “Evaluation on Two Stroke Engines Scavenging Models,” SAE Technical Paper 970358 1997 10.4271/970358
- Lemke et al. “Cylinder And Piston Assemblies For Opposed Piston Engines” Patent Application Publication US2010/0212637