Transonic flutter simulations using an implicit aeroelastic solver

Flutter computations are presented for the AGARD 445.6 standard aeroelastic wing configuration using a fully implicit, aeroelastic Navier-Stokes solve r coupled to a general, linear, second-order structural solver. This soluti on technique realizes implicit coupling between the fluids and structures u sing a subiteration approach. Results are presented for two Mach numbers, M -infinity=0.96 and 1.141. The computed flutter predictions are compared wit h experimental data and with previous Navier-Stokes computations for the sa me case. Predictions of the flutter point for the M-infinity=0.96 case agre e well with experimental data. At the higher Mach number, M-infinity=1.141, the present computations overpredict the flutter point but are consistent with other computations fur the same case. The sensitivity of computed solu tions to grid resolution, the number of modes used in the structural solver , and transition location is investigated. A comparison of computations usi ng a standard second-order accurate central-difference scheme and a third-o rder upwind-biased scheme is also made.