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Propulsion

Improving Hybrid Electric Propulsion Efficiency
Electrically driven turbine engine compressor and propulsion fans require a large stability margin against stall conditions to avoid unwanted performance issues while undergoing transients in operating conditions. This stability margin, while it maintains safe operation, also necessarily reduces the engine performance. Despite extensive research efforts, no viable alternative methods for reducing the operable stability margin and improving engine performance exist. This current innovation, originally conceived for stall prevention, offers a solution by utilizing a supercapacitor in line with an electric motor and motor controller to rapidly change a compressor or propulsor fan speed. The use of the supercapacitor enables rapid extraction, or addition of power, to prevent the fan from stalling.
Additionally, this novel drive motor may be used for sensing stall event precursor signals by using the motor controller to detect variations in torque on the shaft caused by variance in loading on the blade system. The improved stall avoidance capabilities allow an engine fan to operate more efficiently, providing more thrust for a given frontal area, increasing operational range, reduced weight, and improved operational safety.
The related patent is now available to license. Please note that NASA does not manufacture products itself for commercial sale.