Multi-Point Optimization Study of Hydrogen-Fueled, Low-Boom Supersonic Transport

Abstract

Many projects have made efforts to realize commercial supersonic transports (SSTs). These trials have revealed many barriers to the successful completion of various necessary project goals related to supersonic cruise efficiency, sonic boom annoyance, economic viability and also the development of solutions for avoiding environmental problems. The shift of aircraft fuel from kerosene to liquid hydrogen will come in the near future. The purpose of this study is to discuss the feasibility of a hydrogen-fueled, low-boom SST designed to carry 50 passengers for a range of 3,500 nm at a Mach 1.6 cruise speed using a method which considers the effects of hydrogen and incorporates the sonic boom minimization theory. A multi-point optimization using a genetic algorithm is conducted. The objective functions are to maximize range, minimize takeoff weight, W_TO, and to minimize the difference of equivalent areas, ΔA_E, which is a metric about sonic booms. The design variables were the fuselage fineness ratio, cruise lift coefficient and wing area, which are fundamental for aircraft performance. The results show that there are trade-off relationships among them. By analyzing the higher-ranked populations that have lower ΔA_E, the promising range of a wing area, a cruise CL, and an altitude for the reduction of ΔA_E are revealed.