Transonic Flutter Analysis of an Airfoil with Approximate Boundary Method

Numerical simulation of aircraft’s flutter is rather expensive and time-consuming. In order to save expense and calculating time, we apply first-order approximate conditions to solve the unsteady transonic Euler equations coupled with aeroelastic equations. Assuming that the airfoil is thin and undergoes small deformation, we implement wall boundary conditions on nonmoving mean wall positions. Then the firstorder approximate equation of momentum is obtained by using Taylor expansion. Unsteady transonic Euler equations are solved on stationary Cartesian grids. Calculation of the aerodynamic behavior is performed for NACA 64A010 airfoil in transonic flow, while the flutter boundaries of AGARD wing model and NACA 0012 benchmark model are calculated for aeroelastic simulation. The results are in good agreement with other numerical and experimental results, preliminarily indicating that the first-order approximate conditions are effective for aeroelastic simulation.