AERODYNAMIC DESIGN OPTIMIZAITON OF HYPERSONIC WING OVER WIDE MACH-NUMBER RANGE CONSIDERING LIFT MATCHING

Aerodynamic shape optimization of a hypersonic aircraft over a wide Mach-number range is still challenging, due to the difficulties in cutting down the huge computational cost of high-fidelity CFD simulations and the reasonable compromise between aerodynamic performances at different speed ranges. To address this problem, by applying surrogate-based optimization algorithm, this paper newly proposes a wide-Mach-number-range optimization method considering lift matching, which could improve the usable lift-to-drag ratio (L/D) of the wing when its lift matches the weight of aircraft at different speed ranges. A RANS (Reynolds averaged Navier-Stokes) flow solver is adopted to evaluate objective and constraint functions; Kriging surrogate model combined with a parallel infill-sampling method and a multi-round strategy are employed to find the global optimum. First, aerodynamic performance of the baseline configuration of a hypersonic wing is evaluated and analyzed, and the results show that the wing has a reasonable maximum L/Ds but insufficient usable L/Ds. Then, to increase usable L/Ds of the wing over a wide Mach-number range, planform shape optimization and profile shape optimization are conducted, and significant improvement has been observed. Results show that the hypersonic and supersonic useable L/D of the optimized wing are increased by 10.08% and 29.21% respectively, under the premise that the take-off lift at low speed does not decrease and a better performance over a wide Mach-number range is obtained, which verify the effectiveness of the proposed method.