Influence of the Wind Tunnel Model Mounting on the Wake Evolution of the Common Research Model in Post Stall

This work describes the influence of the wind tunnel support system on the wake flow and associated forces acting on the CRM aircraft configuration in post-stall conditions at subsonic Mach numbers. Unsteady scale-resolving simulations at \(\alpha =18^{\circ }\), \(M_{\infty }=0.25\) and \(Re_{\infty } = 11.6\cdot 10^6\) were carried out using the CRM with and without a support sting, respectively. A predominantly local effect of the sting was observed at these conditions, causing significant deflection of the local flow direction near the sting. The sting’s shape causes downward deflection near the horizontal tailplane, decreasing that surface’s effective angle of attack and its lift coefficient. This results in a reduced overall lift coefficient \(C_L\) and a significantly reduced nose-down pitching moment \(C_{My}\). The wing pressure distribution is only weakly affected.