Flow simulations for the second aeroelastic prediction workshop using the EZNSS code

The paper presents numerical simulations that were performed with the EZNSS flow solver for the second Aeroelastic Prediction Workshop (AePW). The reference test cases for the AePW are based on two wind tunnel experiments of the Benchmark Supercritical Wing (BSCW), including a flutter test, and forced excitation tests. Three cases were adressed, at different transonic flow conditions: Two cases at lower Mach numbers of 0.7, 3°angle of attack (AoA), and 0.74, 0°AoA, and one more physically compex case at Mach 0.85, 5°AoA. The cases were analyzed with the EZNSS code, using several computational setups and turbulence models. The simulations were able to predict accurately the flutter response and the response to prescribed motion at the lower Mach number. The higher Mach number case, which involves a strong shock, separated flow behind the shock, and some flow unsteadiness, was more challenging. In the static analysis, different turbulence models yielded different upper-surface shock positions, and none of the models were able to capture accurately the pressure recovery behind the shock. However, the unsteady aerodynamic response to prescribed pitch motion was simulated with good correlation to the wind tunnel data. The paper also presents flutter predictions based on unsteady aerodynamic reduced-order modeling (ROM) thus validating and assessing the efficiency of the ROM, and the flutter prediction methodology.