Abstract
This paper conducts improved delayed detached eddy simulation (IDDES) to numerically investigate the performance of a three-dimensional (3D) aircraft control surface using coflow jet (CFJ) active flow control. For the numerical validation with the baseline control surface that has a large flow separation, the predicted lift coefficient CL and drag coefficient CD achieve a very good agreement with the experiment, and the maximum discrepancy is less than 3.8%. For the 3D CFJ control surface, a small momentum coefficient Cμ of 0.025 generates a 28% of CL increase at 0° sideslip angle with the flow separation removed. At the same time, a higher corrected aerodynamic efficiency (CL/CD)c than the baseline is obtained. With Cμ of 0.26, the CFJ control surface has its CL increased by 99.25% and the CD dropped by 52%. A phenomenon not observed in a regular CFJ wing without flap is that the second suction peak at the flap shoulder is higher than the leading-edge suction peak due to the attached flow with a sharp turning. The CFJ control surface can also sustain a substantially higher stall sideslip angle and flap deflection angle. In conclusion, the 3D control surface using CFJ active flow control is demonstrated by numerical simulation that it can substantially increase the control authority at low energy expenditure.
