The Application of Trailing Edge Circulation Control as a Roll Effector for Unmanned Combat Aerial Vehicles

摘要

The paper reports on a numerical investigation of the use of trailing edge circulation control as a manoeuvre effector (primarily for roll control) on a generic unmanned combat aerial vehicle (UCAV), the DLR-F19 Stability and Control Configuration (SACCON). Trailing edge circulation control is the use of the coanda effect and fluidic injections at the trailing edge of a wing to increase circulation and generate lift. One of the benefits of circulation control is that it does not require mechanically moving parts, significantly reducing the weight of the wings. The Parallel Multi-Block Solver (PMB) developed at the University of Liverpool, has been validated against wind tunnel experiments conducted at the Georgia Institute of Technology and NASA's basic aerodynamic research tunnel on an aerofoil employing trailing edge circulation control. Two turbulence models have been tested for this validation study, the Wilcox k-ω model and Menter's Shear Stress Transport (SST), showing that the Wilcox k-ω model provides the best comparisons with the experimental data. Baseline data for the SACCON with conventional control surfaces from wind tunnel experiments done at the DNW-NWB wind tunnel are used to ensure the correct flow features are being modelled by PMB for the flows encountered by this type of UCAVs and to provide a comparison for the performance of the circulation control devices. The conventional control surfaces have been modelled by blending them with the rest of the wing. Modifications have been made to the DLR-F19, replacing the conventional control surfaces with trailing edge circulation control of the same spanwise extent. The circulation control device has a coanda radius of 0.5% of the reference chord and a slot height to coanda radius ratio of 0.1. The performance is investigated across a range of nozzle pressure ratios and angles of attack. A comparison of the effectiveness of the conventional control surfaces and the circulation control devices as the angle of attack increases is done, showing that similar control moments can be generated by the circulation control at low angles of attack.