Analysis of coupled heat transfer in air cooling channel of aeroengine and thermal isolation layer

The coupled heat transfer in the air cooling channel and thermal isolation layer of an aeroengine is investigated numerically. The low Re number k-ε turbulence model and the SIMPLEC algorithm are employed to simulate the turbulent convection of compressible airflow with variable properties. The wall radiation heat transfer is solved by the Monte Carlo method. The turbulent convection and wall radiation in channel and the thermal conduction in isolation layer are solved simultaneously. By analyzing the numerical results, the mechanism governing the coupled heat transfer and the effects of relevant parameters are discussed. The investigation shows that, under the considered channel and airflow conditions, the outerwall temperature is higher than that of airflow, so both walls are cooled by the airflow. For constant thermal parameters of the isolation layer, the wall radiation and the airflow cooling govern the heat transfer process. Increasing the airflow rate or decreasing the wall emissivities can obviously reduce the outside temperature of isolation layer.