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The effects of elevated acceleration fields on spray cooling heat transfer are discussed in this paper. Spray cooling has proven to be one of the most efficient methods of heat removal. This technology is being transitioned into more advanced applications, such as fighter aircraft that must withstand a wide range of variable acceleration-induced body forces. Heat transfer associated with closed-loop spray cooling will be affected by acceleration body forces, the extent of which is not yet known. To test these various effects, an eight-foot-diameter centrifuge table will be outfitted with a spray cooling system to test for the effects associated with elevated gravity.

The objective of this paper is to describe the design of an experiment that will examine the effects of elevated acceleration environments on a high-temperature, titanium-water loop heat pipe for actuator cooling. An experimental test setup has been designed for mounting a loop heat pipe on an 8-ft-diameter centrifuge table, which is capable of radial accelerations of up to 12 g's. A high-temperature PAO loop will interface the condenser of the loop heat pipe to simulate the rejection of the transported heat to an elevated temperature. In addition to LHP experimentation, a mathematical model has been developed for aerodynamic heating of highspeed aircraft. A flat plate at zero-incidence, used to model an aircraft wing, was subjected to sub- and supersonic flow to examine whether heat will be rejected or absorbed. The results of this analysis will be used to determine the condenser conditions of the loop heat pipe during centrifuge testing.

Recent advances in aircraft technology have raised much concern over the manner in which aircraft thermal management is carried out. These advances range from the incorporation of high-power electronics to transporting thermal loads at high temperatures. These types of technological advances have brought about a necessity for new aircraft thermal management architectures in order to maintain reasonable cost, size, weight, and power requirements of the overall system. The objective of this study is to address the requirements and performance aspects of existing system configurations in an effort to identify inefficiencies and highlight potential areas for improvement. As a result of this study, a new aircraft thermal management architecture, which can best be described as a vapor-compression thermal bus, is proposed as a replacement for existing technology.