抄録
Direct heat loss is defined as heat flowing directly from the combustion gas to the combustion chamber walls. The authors' group has investigated the direct heat loss at combustion chamber walls by means of heat transfer analysis using measured instantaneous wall surface temperature. This study focuses on the cylinder liner of a D.I. diesel engine. The cylinder liner wall receives heat from various objects such as the combustion gas, the piston and the piston rings. Incoming heat from the gas to the wall is separated so that the state of the direct heat loss and the heat loss ratio can be evaluated. As a result, this study shows that the heat loss ratio of the cylinder liner occupies approximately 4% of the heat of supplied fuel and also approximately 20% of the total heat loss through all combustion chamber walls other than the valves.