Design and testing of a high-speed spin test for evaluating pulse alternator windage loss effects

Advanced pulse alternator designs require rotor surface speeds in excess of 1000 m/s. High tip speeds and an operating environment consisting of partial vacuum result in frictional windage losses and subsequent heating of the rotor and stator surfaces. Analytical models for cylindrical rotor windage loss exist. However, solving the combined fluid dynamics and thermal conduction problem for this specific operating regime requires significant code development. A series of spin tests with incremental levels of complexity have been designed and tested and are presented in this paper. The tests are intended to validate windage loss and heating codes used in the pulse alternator rotor design.