Aerothermal performances of a rotating turbine disk cavity with non-uniform wall temperature profiles in an aero-engine

The problems of fluid flow and heat transfer in a turbine disk cavity are highly complex under rotation-induced Coriolis and buoyancy forces. This study aims to evaluate the influence mechanisms of the convective heat transfer caused by a non-uniform temperature distribution of the rotor disk in a turbine disk cavity considering compressibility, heat dissipation, and variable physical properties. The accuracy of a numerical simulation program for turbine disk cavity prediction modelling is verified with the experimental data. Certain results revealed that the average Nusselt number of the rotor disk ranges from 288.53 to 323.41 when the rotational speed increases from 3000 to 9000 rpm for a uniform constant wall temperature distribution and in the range of 355.39–876.24 for a non-uniform wall temperature distribution. The non-uniform temperature distribution of a rotor disk would affect the Nusselt number and torque coefficient owing to the different incoming mass flow through the wall Ekman layer, which would be sensitive to thermal performance and marginally sensitive to the aerodynamic performance of the disk cavity under high rotational speed conditions. In particular, the correlation of the Nusselt number is proposed to be a comprehensive performance evaluation in the case of the non-uniform temperature distribution effect of a rotor disk. It is primarily influenced by the wall heat dissipation on the rotor disk, adiabatic wall temperature, and wall suction flow rate. Thus, these observations can provide references for evaluating the complex heat management of turbine disk cavities.