Application of a Hot Gas High Pressure Rotary Vane Motor to Aircraft APU Starting

Analyses and tests have been conducted on a hot gas rotary vane motor suitable for aircraft APU starting over the temperature range of -65° to + 130°F (-54° to +54°C).

Testing of the motor has been accomplished with gaseous nitrogen and hydrazine-based monopropellant hot gas decomposition products.

Revisions to the motor configuration reduced total gas consumption 52 percent compared to the original baseline and eliminate end clearance sensitivity.

Analytical studies, verified by test results, indicated the effect of friction coefficient, blade weight, and venting of the blade on overall internal friction. Further studies evaluated linking pairs of blades to minimize centrifugal force effects.

Tests currently in progress are aimed at selecting the optimum blade material.