T-tail transonic flutter wind tunnel test. Part 2: Numerical restitution

The article presents the main results of the numerical restitution of the test campaign carried out on a T-tail flutter model in subsonic and up to high transonic domains. The wind tunnel tests were carried out in ONERA’s S2MA pressurized wind tunnel at the end of 2022 as part of the Clean Sky 2 airframe ITD program, and will be presented in a companion article [1]. Numerical results obtained with high-fidelity fluid-structure coupling simulations performed with the CFD solver elsA (proprietary ONERA-Safran) [2] are compared with wind tunnel test data and low-fidelity numerical results. Four T-tail configurations were measured during the test campaign, in order to explore the influence of yaw angle and dihedral on flutter behavior. These different geometries were also used to assess the ability of our numerical tools to predict corner flow aerodynamic phenomena occurring in the region of tail surface intersections. A good correlation is obtained between numerical and experimental steady pressure coefficients, even at elevated Mach numbers. Regarding unsteady pressure coefficients, aerodynamic responses were computed for a forced motion applied to the T-tail model, and the effects of different excitation parameters were evaluated. The aeroelastic stability of different T-tail configurations was also studied, and high-fidelity coupled simulations were used to predict the evolution of critical pressure as a function of Mach number.