Shape Parameters Optimization For Wing And Wingtip Of Amphibious Aircraft Based On RBF

Amphibious aircraft has more adaptability than general aircraft, for it can take off and land on either land or water. It can be applied to the maritime patrol and anti-submarine, forest fire fighting and rescue missions, etc. China has numerous islands and waters. It has up to 18,000 km coastline, and it's island shoreline is more than 14,000 km. Amphibious aircraft has very broad application in china.An optimum method of the shape parameters for amphibious aircraft's wing and wingtip is studied in this paper. Radial Base Function (RBF) is introduced to solve the problem. The methodology consists of major four steps. In the first, the shape parameters of wing and winglet are selected, with improved random selection method enter sample points are got, and the approximate model of wing and winglet is constructed by RBF. In the second step, the iteration of RBF's enter sample points is designed. Firstly, the performances of RBF network with different numbers of enter sample points are studied. In the forth, optimization object is minimum of induced drag for wing,with/without the bending moment constrain at wing root,combined with sequence quadratic programming or quasi Newton methods,respectively. The results show that optimization effect is satisfied. Research for optimum design of wingtip can provide reference to engineering application.