Development and application on an unsteady measurement method of heat transfer for aero-engine rotating disk cavity with complex thermal boundary conditions

The measurement method of convective heat transfer coefficient is the technical bottlenecks in carrying out the current thermal analysis and refined design of rotating disk cavity. In order to measure the convective heat transfer coefficient of rotating disk with high rotational speed under complex thermal boundary conditions, this paper proposes a new strategy for acquiring convective heat transfer coefficient by combination with experimental data and numerical calculation of unsteady thermal conductivity in the solid domain. The convective heat transfer coefficient is indirectly obtained at the corresponding position by predicting heat flux through the loading of transient temperature field of solid surface measured in the experiment. Moreover, the effects of Fourier number and measurement random errors on the accuracy of the measurement method during unsteady heat transfer are investigated. The results show that the uncertainty of the convective heat transfer coefficient corresponding to the measurement method is less than 8.20 % when the measurement error is considered. Asymmetric flat plate heat transfer experiments are also carried out. The experimental results show that the deviation of the experimental results from the empirical correlation formula in the range of mass flow rate from 200 g/s to 400 g/s is less than 8 %, which proves that the measurement method can accurately measure the convective heat transfer coefficient under the asymmetric thermal boundary conditions. This paper provides a new convective heat transfer coefficient measurement technique for subsequent rotating disk cavity heat transfer experiments under complex thermal boundary conditions.