Computational and Simplified Analytical Treatment of Transonic Wing/Fuselage/Pylon/Store Interactions

Transonic modified small-disturbance theory has been employed to numerically model the flowfield around wing/fuselage/pylon/store configurations. A fine grid region enclosing the wing/pylon/store is embedded within a global crude grid and a successive crude-fine relaxation is performed. Using an image point concept, the store and the pylon are introduced into an existing wing/fuselage program, thus avoiding excessive additional computer memory requirements. Comparison of results with experiments on the F-5 wing with a pylon/store arrangement is presented showing good agreement. A study of the roles of pylon height, store diameter, pylon span mount location, angle of attack, and Mach number relative to the achievement of optimum LID from beneficial nonlinear interference is presented. In addition, a simplified analytical approach to compute the loading on the store using an "immersion theory" is indicated and validated against experiments.