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Testing of a Loop Heat Pipe Subjective to Variable AccelerationsThe effect of accelerating forces on the performance of loop heat pipes (LHP) is of interest and importance to terrestrial and space applications. They are being considered for cooling of military combat vehicles and for spinning spacecraft. In order to investigate the effect of an accelerating force on LHP operation, a miniature LHP was installed on a spin table. Variable accelerating forces were imposed on the LHP by spinning the table at different angular speeds. Several patterns of accelerating forces were applied, i.e. continuous spin at different speeds and periodic spin at different speeds and frequencies. The resulting accelerations ranged from 1.17 g's to 4.7 g's. This paper presents the first part of the experimental study, i.e. the effects of a centrifugal force on the LHP start-up. Tests were conducted by varying the heat load to the evaporator, sink temperature, magnitude and frequency of centrifugal force, and LHP orientation relative to the direction of the accelerating force. The accelerating force seems to have little effect on the loop start-up in terms of temperature overshoot and superheat at boiling incipience. Changes in these parameters seem to be stochastic with or without centrifugal accelerating forces. The LHP started successfully in all tests.
Document ID
20000101591
Document Type
Preprint (Draft being sent to journal)
Authors
Ku, Jentung
(NASA Goddard Space Flight Center Greenbelt, MD United States)
Rogers, Paul
(Army Tank-Automotive Research and Development Command Warren, MI United States)
Hoff, Craig
(Kettering Univ. Flint, MI United States)
Date Acquired
September 7, 2013
Publication Date
July 1, 2000
Subject Category
Fluid Mechanics And Thermodynamics
Meeting Information
30th International Conference on Environmental Systems(Toulouse)
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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