Enabling Pump Technologies for Deep Throttle Ascent/Descent Engine Operation

Methane fueled ascent / descent space engines in the 10,000 to 25,000 lbf thrust class require deep throttle capability, placing unique challenges on the turbopumps. Previous engine throttle-ability studies have required both LOX and fuel turbopumps to operate at ratios of volumetric flow rate to shaft speed (Q/N) of 0.2 to over 1 for 10:1 engine throttle operation. Such operational ranges are particularly difficult for pump axial inducers and vaned radial diffusers. Both are prone to fluid separation and stall at low Q/N operation and excessive passage blockage due to cavitation at high Q/N values. The proposed innovation combines two separate technologies to address the inherent design shortcomings of the inducer and diffuser under operation at both low and high Q/N extremes.