Abstract
The exhaust gas recirculation (EGR) method is expected to be effective for reducing NOx contained in the exhaust gas of D. I. diesel engines used extensively in recent years. With the EGR activated, the intake gas temperature may be raised while the combustion temperature is lowered, which may increase the mean gas temperature in the combustion chamber, making the combustion more complex. For a detailed study on the thermal loads of the combustion chamber wall with the EGR activated, we conducted simultaneous measurements of the instantaneous heat flux flowing into the piston surface. As a result, the state of heat loss at the piston surface in cyclic operation with the EGR activated was clarified by determining the instantaneous heat flux flowing into the piston surface.