Engine thermal balance test

An engine body lumped parameter model for engine body heat transfer was introduced to evaluate the engine heat dissipation.The thermal balance tests in stable state and warm-up state were conducted,which could determine the engine coolant requirement and the mean heat transfer coefficient used in the lumped parameter model.The stable state results showed that the combustion heat distribution in subsystems can be the base of engine design.The mean heat transfer coefficient changes little with the temperature difference between engine body and air condition,and can be assumed as a fixed value in the warm-up state.On this account,engine body mean temperature can indicate the engine body thermal state in the lumped parameter model to evaluate the engine body thermal condition in the warm-up state.