Optimal Cruise Airspeed for Hybrid-Electric and Electric Aircraft: Applications to Air Mobility

TL;DR

This paper develops a mathematical approach to determine optimal cruise airspeed and minimize operating costs for hybrid-electric and electric aircraft, integrating these solutions into path planning algorithms for sustainable air mobility.

Contribution

It introduces a novel method using a quintic polynomial derived from Pontryagin's principle to optimize cruise airspeed and cost for hybrid-electric aircraft.

Findings

Optimal cruise airspeed minimizes direct operating costs.

The method effectively integrates into RRT* path planning.

Applications demonstrated in travel and city scenarios.

Abstract

Electric and hybrid-electric aircraft can help our society transition towards more sustainable aviation and lower greenhouse gas (GHG) emissions. This paper provides solutions to minimize the direct operating cost (DOC) for hybrid-electric aircraft. The solution is the positive real root of a quintic polynomial which is derived using Pontryagin's minimum principle. By properly selecting a hybridization factor, one can also find the cruise airspeed corresponding to the minimum DOC of an electric aircraft. The optimal airspeed is integrated into the Rapidly-exploring Random Trees Star (RRT*) path planning algorithm. The minimum DOC solutions are investigated in a hybrid-electric international travel scenario and the path planning approach is applied to an electric aircraft city scenario.