Transonic computational method for an aft-mounted nacelle/pylon withpower effect

A computational method has been developed for computing transonic flows about an aft-fuselage mounted capped-nacelle/pylon configuration with/without propeller power. A hybrid conformal-mapping/transfinite-interpolation scheme is developed to generate body conforming grid systems; a multigrid line-relaxation scheme is applied to solve the potential flowfield; an Euler correction method based on the Clebsch transformation is employed to simulate the power effect; and an inverse boundary-layer method is incorporated to calculate the viscous flows over the pylon and fuselage surfaces. Included are comparisons of the solutions with available test data and the solutions of a panel method. The importance of the fuselage boundary-layer effect on the pylon pressure distribution is studied. The present method has been shown to be reliable, efficient, and general and has been successfully applied to compute a wide range of flow conditions, including those of high angles of attack.