Sizing and Analysis of a Lift-Plus-Cruise Aircraft with Electrified Propulsion

This paper demonstrates an integrated approach to the sizing and analysis of all-electric, hybrid-electric, and turboelectric variants of a lift-plus-cruise urban air mobility vertical takeoff and landing concept using the Parametric Energy-based Aircraft Configuration Evaluator. In lieu of assuming a point mass performance model, the aircraft is trimmed explicitly for nominal and off-nominal flight conditions for sizing propulsion system components and evaluating mission energy usage. In lieu of using historical tail volume ratio guidelines for stabilizer sizing, an explicit dynamic stability analysis is incorporated to determine the stabilizer size that achieves specified bare airframe handling qualities targets. The effects of varying battery specific energy, C-rate, wing loading, hover disk loading, mission range, and cruise speed on the sizing of the three propulsion architectures are explored. A comparison of the weight breakdown of the three propulsion variants when sized to the same maximum takeoff mass is presented. The sensitivity of the sizing results to the requirement of full vs reduced payload capability at high, hot hover conditions is also assessed. In addition to being insightful, the presented results reinforce the need to incorporate more physics-based analyses, additional stability and control considerations, and configuration optimization studies, which form natural avenues for follow-on work.