Aircraft Design with Maneuver Load Alleviation and Natural Laminar Flow

摘要

The effects of maneuver load alleviation (MLA) and natural laminar flow (NLF) on aircraft performance are evaluated at the level of conceptual design. We use low-order, physics-based methods to capture the interaction and tradeoff among laminar flow, com pressibility, active load control and wing structure efficiency. The results demonstrate that MLA can tilt the balance of the transonic Mach-sweep-thickness (MAT) trade in favor of a high aspect-ratio, low-sweep natural laminar flow wing. A Mach 0.78 transport aircraft designed with these complimentary features may achieve some 10% lower direct operating cost (DOC) and 16% reduced fuel burn relative to a conventional turbulent design. The cost and fuel savings increase to 15 and 22% if the aircraft can slow down to Mach 0.74. Finally, sensitivity studies indicate that much of gains from the NLF and MLA design can be achieved at reasonable control deflections.