Advanced Propulsion and Power Concepts for Large Size Class Unmanned Aerial Systems (UAS)

ABSTRACT: This proposal outlines an innovative parallel hybrid compound differential drive system with infinite variable speed inputs from either the internal combustion/heavy fuel engine (IC/HFE) or the high speed permanent magnet motor (PMM). This variable speed input optimizes propulsion system performance and efficiency. This approach delivers nearly double the peak takeoff/climb power of electrically compounded superchargers and/or PMM direct power (contributing up to 30% of the input power). An innovative direct injected/heterogenous charged IC/HFE with a brake thermal efficiency approaching 50% and the variable compression valves that increase the CI/HFE expansion ratio and efficiency while reducing exhaust energy below propeller noise. The compound differential transmission allows remote, low torque soft/start cabability. Reliability and maintainability are vastly improved using a robust high-speed, multi-fuel combustion system capable of stable operation on JP-8/DF-2 fuels (with the added safety and redundancy inherent with twin pack parallel hybrid propulsion). A hybrid fuel cell assisted battery pack, thermal electric waste heat exhaust recovery, and integrated photo voltaic solar panels are potential sources of supplemental power to extend the electrical energy supply essential to meeting the 24 hour duration program goal. BENEFIT: Maximum hybrid core engine power densities below 1lb/hp. - Double the peak takeoff power by electrically assisted supercharging and/or direct 50% power contribution from the brushless PM motor. - Extended S-UAS range and endurance from an efficient direct injected heterogenous charge combustion system capable lean burn/part load operation on logistically available JP-8/DF-2 fuels. - A reliable means of remote starting through a variable speed differential gear system. - Low noise propulsor for covert missions. Commercial Benefits: - Lightweight, multi-fuel hybrid propulsion system suitable for all aspects of ground, marine, and aviation segments in need of improved proulsion system efficiency.