Numerical Investigation of Tangential Blowing at the Rudder of a Vertical Tailplane Airfoil

A numerical 2D investigation of a vertical tailplane airfoil using active flow control with tangential blowing over the rudder shoulder is conducted. The intention of the flow control application is to increase the maximum lift or side force which can be created by the vertical tailplane at critical conditions like the one-engine-inoperative failure case. On the highly deflected rudder a large separation can be found without blowing. With tangential blowing it is shown that fully attached flow can be achieved. The flow simulations performed are based on the Reynolds-averaged Navier-Stokes equations. The parameters momentum coeffi�cient, slot height and angle of attack of the oncoming flow are varied to assess sensitivities and the influence on the results. Furthermore, the influence of a geometric detail in the vicinity of the slot exit is investigated, namely the existence or omission of a step behind the slot exit. Finally, the influence of the turbulence model is studied where besides the Spalart and Allmaras turbulence model with rotational and curvature correction (SARC) also the SAO and RSM turbulence models are applied