Analysis on thermal control approach for a bare shaft of rudder in a hypersonic vehicle

A 5 mm-wide gap of a shaft connected to the rudder in a hypersonic vehicle is exposed without any heat insulation bearing serious aerodynamic heating. A new thermal control approach combining CO₂ flow forced convection in the central inner channel with copper-plating on the outer surface is proposed to prevent the temperature of the gap from exceeding the material's highest tolerance temperature. Based on the integrated thermal management, CO₂ first cools the electronic equipment after being gasified from a high-pressure cylinder, and then moves into the shaft for active thermal control. The thermal control performance is simulated, and the results show the proposed method could satisfy with the thermal control requirements, however, the thermal control requirements could not be fulfilled if the forced CO₂ flow convection or the copper-plating was used alone. The mass penalty was estimated within a weight of 11 kg which is quite feasible for engineering applications.