The existing rotating heat pipe (RHP) technology was examined and further developed for possible cooling applications in high-speed rotating electrical machines required for future designs of more-electric aircraft. Several technical papers covering the results of the design, fabrication, and testing of the RHP hardware in the low-to-intermediate rotational speeds from 500 to 7500 rpm have been published in recent years. In this investigation, performance results are presented for stainless steel 316 - methanol and stainless-steel 316 - water high-speed rotating heat pipes (HSRHPs) that were tested at speeds up to 30,000 rpm for the first time in the history of RHP research.

The HSRHPs were cooled by air and oil jets in separate tests to compare their relative performances. Interesting temperature profiles and test results are presented for the HSRHPs that were heated by an induction heater and tested in the temperature range of 20-250°C for power inputs from 250 to 1300 W.