3736. Hydrogen Fuel Cell Power System Weight Challenges in VTOL Aircraft

Paper

Abstract

The ‘More Electric Aircraft’ movement is maturing past actuation, flight controls and backup power solutions. Starting with Unmanned Aerial Vehicles (UAV) and now growing into the passenger vehicle market, vertical lift aircraft engineers are developing electric driven propulsion systems.One of major limitations with electrification is endurance or range. Batteries only offer so much energy capacity before mass becomes a limiting factor. Hydrogen fuel cells offer another solution for on board electrical generation but present many of their own technical challenges.In cases of typical passenger vertical lift aircraft, electrification supplants traditional gas turbines and liquid fuel tanks with electric motors, power electronics, and either batteries or hydrogen fuel cells for an energy source. For Class I UAVs (55 lbs. total weight) or Class II UAVs (up to 300 lbs. total weight), batteries could be replaced by smaller, simplified fuel cells, electronics and hydrogen storage.The electric powertrain evolution will have a strong impact on several aspects of aircraft technology development, especially mass properties and center of gravity as the emerging technology is not limited to time honored positions and locations of legacy components. This paper researches some of the risks and opportunities with electrifying the propulsion systems of vertical lift aircraft.