CFD-Aided Evaluation of Reynolds Number Scaling Effect Accounting for Static Model Deformation

A static aeroelasticity analysis is accomplished for an ONERA-M5 wind tunnel calibration model. The Reynolds-averaged Navier-Stokes (RANS) solution obtained using the cell-wise relaxation implicit discontinuous Galerkin (DG) computational fluid dynamics (CFD) solver is fed into the structural analysis method to iteratively determine the aerodynamic equilibrium configuration of the wind tunnel model. For the freestream conditions of M=0.84, α=-1.0°, Re=4 × 106, P0=220 kPa and T0=274 K, the aerodynamic equilibrium shape is successfully obtained within three iterations. The maximum deformation of 3.11 mm appears at the wing tip of the wind tunnel model, and the resulting change in aerodynamic force produces a nose-down effect. A detailed examination reveals that the deformation mostly causes pure bending which reduces the effective angle of attack for the present swept wing. Moreover, we attempt to split the change in aerodynamic coefficients into that due to the model deformation effect and that due to the Reynolds (Re) number effect. By comparing the computed results for Re=1 × 106 and Re=4 × 106, it is indicated that an increase in lift coefficient due to the Re number effect is totally offset by the model deformation effect. It is also shown that the amount of drag reduction can be overestimated due to the model deformation effect. In addition, a CFD-aided data correction method utilizing the wind tunnel data is discussed.