Study on effect of cylinder head bridge zone structure and two-phase flow parameters on boiling heat transfer

For research on heat load in heavy duty diesel engine cylinder head bridge zone, the bridge zone structure was simplified as rectangle + V-shape to establish the parametric model. By using gas-liquid two-phase flow boiling heat transfer model, the fluid-solid coupling heat transfer system was simulated. On the basis, effects of cooling water inlet velocity and temperature, boiling bubble size and V-shape height and lower width on bridge zone highest temperature were examined by using the experimental design method. Results show that the bridge zone highest temperature decreases with cooling water inlet velocity, bubble size, V-shape height and lower width increasing, and increases with cooling water inlet temperature increasing; effect of V-shape height change on boiling heat transfer is greater than that of change in lower width; effect of cooling water inlet velocity change on boiling heat transfer is more obvious than that of inlet temperature.