Prediction of Control Effectiveness for a Highly Swept Unmanned Air Vehicle Configuration

A study into the prediction of the effectiveness of different trailing-edge controls on an unmanned combat aerial vehicle configuration, on which complex vortical flow develops at moderate to high angles of attack, is described. Stability and control of these vehicles is demanding and requires early knowledge of the changes in forces and moments from control-surface deflections. Computational results are compared with data from wind-tunnel tests over the Mach number range 0.146≤M≤0.9 for undeflected controls. The effectiveness of the controls at subsonic and transonic conditions is then discussed. The influence of the mesh treatment and turbulence model on the realism of the predictions is considered. The computational-fluid-dynamics predictions show good agreement with measurements and show limited sensitivity to geometry treatment and turbulence model for the flow conditions where the controls are effective. Computational fluid dynamics is shown to be capable of predicting the control-surface influence, even at high speed