Performance of a Low Heat Rejection Diesel Engine With Air Gap Insulated Piston

Introduction The second law requirement of Thermodynamics necessitates the inevitable heat loss to the coolant to realise work output. Any saving in this part of the energy distribution would either increase the energy lost through exhaust gases or increase the power output. Considerable efforts are under way to reduce heat loss to the coolant by various researchers. However, the results are a little confusing as to whether the insulation would improve or deteriorate thermal efficiency. The two approaches that are being pursued to decrease heat rejection are (1) ceramic coating and (2) air gap insulation. Both these methods are still having problems. Ceramic coatings are found to be peeling off over a period of operation. There are serious problems of leakage of gases in the case of air gap insulation. A two zone combustion model was used by A study of the existing literature on LHR engines thus reveal