Abstract: An aerodynamic and flight dynamic coupling computation method and software are developed to simulate the virtual flight of a missile. The control equations are unsteady Navier-Stokes equations and rigid body 6-dof flight dynamic equations. The flow solver is a finite-volume solver of structure grid which solves unsteady Reynolds averaged Navier-Stokes (RANS) equations with dual time stepping and a Spalart-Allmaras turbulence model. Adams prediction-correction method is used to couple the aerodynamic and flight mechanic computation, and the chimera method is used to simulate relative motions. This methodology is used to simulate the longitudinal virtual flight for a NASA missile with long middle strakes to study the effects of coupling method and time step. Simulation results show that the third order Adams prediction-correction method can simulate in a much higher time step while keeping an equal precision level to obviously decrease simulation time. Finally, this approach is used to simulate free-to-roll motions and longitudinal virtual flights with results showing good agreements with wind tunnel test.

Key words: virtual flight, numerical simulation, prediction-correction, chimera grid, strake wing missile, free to roll motion