The sharp leading edges of a hypersonic vehicle are promising for the enhancement of its aerodynamic performance. However, they need a cooling mechanism because they are exposed to extremely high heat flux during reentry or hypersonic cruise, which easily heats up the surface materials beyond their temperature limits. This study explores the concept of a leading edge with planar heat-pipe cooling for which the whole inner surfaces are directly covered with a capillary wick. Its isothermal characteristic and simple configuration can provide robustness; however, due to the uniqueness of the planar type, the thermofluid characteristics should be investigated. Therefore, two kinds of heating tests (the inside visualization test and high-temperature test) were conducted using water as a working fluid. The gravity effects were surveyed, changing the test article attitude. The results showed that the planar concept worked as expected; no large temperature distribution was observed along both the chord and span directions, even in a nose-up attitude or a top heat configuration; the heat transfer performance was improved in nose-down attitude. During the heat-pipe operation, a heat transfer coefficient approximately 100 times higher than that of an evacuated operation was obtained. Visualizing inside the test article revealed that the screen mesh wick was properly covered with condensed water and that typical bubble formations of nucleate boiling were observed around the tip in some cases.
Thermal Performance and Flow Visualization of a Planar Heat-Pipe Leading Edge
Journal of Spacecraft and Rockets ; 56 , 3 ; 771-779
2018-12-26
9 pages
Article (Journal)
Electronic Resource
English
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