MULTI-POINT DESIGN OF A SUPERSONIC WING USING MODIFIED PAR-SEC AIRFOIL REPRESENTATION
T. Yotsuya, Masahiro Kanazaki, Yoshikazu Makino, Kisa Matsushima · Blucher Mechanical Engineering Proceedings · 2014
This paper discusses the multi-point aerodynamic design of a supersonic wing.Herein, supersonic transport (SST) which cruises over land at a low Mach number (around M = 1.15) and cruises over sea at a high Mach number (around M = 2.0).No sonic boom is said to be heard on the ground because of the "Mach cutoff effect."This concept requires that high aerodynamic performance should be achieved at a high and a low Mach number cruise, simultaneously.Thus, this study considers a multi-point design aerodynamic problem.The objective functions considered here are employed to maximize the lift-to-drag ratio at cruise speed M=1.15, and M=2.0, simultaneously.Thus, the several flow conditions should be considered.To solve such multi-objective design problem, efficient global optimization (EGO) was applied.The EGO process is based on Kriging surrogate models, which were constructed using several sample designs.Subsequently, the solution space could be explored through the maximization of expected improvement (EI) values that corresponded to the objective function of each Kriging model because the surrogate models provide an estimate of the uncertainty at the predicted point.Once a number of solutions have been obtained for the EI maximization problem by means of a multi-objective genetic algorithm (MOGA), the sample designs could be used to improve the models' accuracy and identify the optimum solutions at the same time.In this paper, 193 sample points are evaluated for the constructions of the Kriging model, and several design are compared.Remarkably, the kink airfoil should be similar to typical subsonic airfoil to achieve higher aerodynamic performance not only at high speed cruise but also low speed cruise in spite of supersonic cruise.