Heat Insulation of Combustion Chamber Walls — A Measure to Decrease the Fuel Consumption of I.C. Engines? 870339
Experimental investigations were made with a single-cylinder direct-injection Diesel engine with heat-insulated piston. The most important result is an inferior economy compared with the not insulated aluminum-piston engine. It was found that this phenomenon is not caused by neither a changed combustion process nor increased blowby nor different friction losses, but rather by a drastic increase of the heat transfer coefficient during the first part of combustion with increasing surface temperature. This is taken into account in a modified equation for the heat transfer coefficient. Cycle-simulations using this modified equation show that there is neither a gain in fuel economy of naturally aspirated nor of turbocharged nor of turbocompound Diesel engines with “heat insulated” combustion chamber walls.
Citation: Woschni, G., Spindler, W., and Kolesa, K., "Heat Insulation of Combustion Chamber Walls — A Measure to Decrease the Fuel Consumption of I.C. Engines?," SAE Technical Paper 870339, 1987, https://doi.org/10.4271/870339. Download Citation
Gerhard Woschni, Walter Spindler, Konrad Kolesa
Technische Universität München
SAE International Congress and Exposition
SAE 1987 Transactions: Reciprocating Engines--Spark Ignition and Diesel-V96-4