Design and Fleet Assessment of Commercial Aircraft with Range and Speed Optimization

Exploring the performance potential of conventional tube-and-wing aircraft is imperative to bridge the gap for sustainable aviation until the adoption of novel configurations. This paper investigates the strategy of reducing design range and cruise speed for the conceptual design of next-generation single-aisle aircraft. The impacts on fuel consumption are evaluated at both vehicle and fleet levels. Performance analysis shows that simultaneously optimizing aircraft design parameters and cruise Mach number can reduce mission fuel burn by 3% compared to the fixed-Mach optimization. The reduced cruise speed also maximizes the benefit of natural laminar flow technology, yielding an additional 5% fuel saving. Shorter design ranges result in smaller airframes and engines, reducing fuel burn by about 1.4% per 500 nmi decrease relative to the long-range vehicle operating at its off-design missions. Tradeoffs between aircraft range capability and fuel savings are captured by the fleet analysis. The results show that 6% of the flights operated by large single-aisle aircraft become infeasible if the aircraft design range reduces to 1500 nmi. The projected 2050 fleet-level fuel savings vary non-monotonically with reduced design ranges, with the highest reduction of 6.4% achieved by a 2500 nmi design among six optimized candidates.