RELATION BETWEEN GAS FLOW PATTERN AND HEAT FLUX ON PISTON CROWN SURFACE

The relation between gas flow and heat flux on the piston crown surface of the pre-combustion type diesel engine was investigated. The gas flow, the collision position of the jet and the direction of flow from the orifice of the precombustion chamber on the piston crown surface were observed by means of the oil film method. At the same time, the heat flux into the piston surface from the gas was measured. From the above-mentioned result, the relation between gas flow and heat flux was deduced. As a result, it was shown that heat flux (mean and maximum during one cycle) is affected by gas flow and gas temperature which are affected by equivalence ratio (Phi). Qualitatively, the farther it recedes from the collision area of the jet, the less the heat flux grows.