Investigation of the flow and heat transfer performance of supercritical pressure hydrocarbon fuel in a novel rotating internal trapezoidal expansion channel

Hydrocarbon fuel is required to cool the rotating turbine blades in order to enable the hypersonic vehicle electricity supply turbine to withstand the impact of hot air. A novel internal trapezoidal expansion type hydrocarbon fuel rotating cooling channel is proposed for heat transfer enhancement of turbine blades. Numerical results show that among the expansion channels studied, the maximum value of thermal performance is obtained for the expansion angle 2 degrees channel. The thermal performance of the channel corresponding to the expansion angle of 2 degrees is maximally increased by 591.4% compared to the 0 degrees channel. The factor of friction of the channel corresponding to the expansion angle of 2 degrees is lowered maximally by 99.7% compared to the 0 degrees channel. The channel thermal performance of the entrance temperature before the temperature of the critical state is improved by a maximum of 911.3% compared to the channel thermal performance of the entrance temperature after the temperature of the critical state. The internal trapezoidal expansion channels overcome the negative effect of the second channel velocity decrease caused by the increase in physical property of the fuel due to centrifugal force, and significantly enhance the second channel heat exchange capacity.