Combustion Chamber Temperature and Instantaneous Local Heat Flux Measurements in a Spark Ignition Engine

Cylinder head combustion chamber and piston temperatures and heat fluxes were measured in a 2.2 L 4 cylinder spark ignition engine. Measurements for the combustion chamber were made at wide open throttle conditions, 1400 rpm to 5000 rpm at 600 rpm increments, additional measurements were made on the combustion chamber at part throttle conditions at 3200 RPM. Piston temperature and heat flux measurements were made at WOT conditions from 1400 to 3200 RPM in 600 RPM increments. Average combustion chamber surface temperatures ranged from 130 deg. C to 248 deg. C, while peak combustion chamber surface temperatures ranged from 142 deg. C to 258 deg. C for WOT conditions. Peak heat flus at the surface for WOT conditions in the combustion chamber ranged from 1.2 MW/m²to 5.0 MW/m². Central region heat fluxes were 2.3 to 2.8 times greater than those in the end gas regions of the combustion chamber. Piston temperatures were 10 to 25 degrees centigrade hotter than corresponding combustion chamber surfaces at WOT conditions. Peak heat flux values in the end gas region of the piston were 2 to 4 times greater than corresponding locations on the combustion chamber at WOT conditions. The Woschni heat transfer model correlated well with the experimental instantaneous local heat flus data. Long term heat flus data indicates that deposit formation greatly modifies surface heat transfer.