Energy efficient active control of the flow past an aircraft wing: RANS and LES evaluation

摘要

Numerical simulations of the flow past a NACA 0015 wing with active control have been performed. The Reynolds number of the flow based on the wing's chord is Re = 2.5 × 10~6. The configuration proposed in this study does not follow the conventional active control methodology past wings. Large blowing surfaces and low jet velocity magnitudes are considered and the energy efficiency of such configuration is examined for a number of variants. Although the momentum coefficient of the injected fluid is similar to most of the referenced studies, the effects on the flow-field are quite pronounced. Strategies for drag reduction and lift increase of the wing are proposed by varying some of the actuation parameters. The present active flow control could be energy efficient at all angles of attack, while in the same time could be able to reduce significantly the total drag of the wing, increase the total lift or combine effectively those favorable effects for better flight performance. The present actuation reduces the profile drag of the wing and influences the flow mainly in two dimensions. Maximum drag decrease could be close to 40% at low angles of attack, with still positive energy income. Supportive Large Eddy Simulations at Re = 2.2 × 10~5 verify the trends of this control, which are predicted by Reynolds Averaged Navier-Stokes modeling and it is shown that the mechanism of drag reduction or lift increase, does not depend crucially upon the unsteadiness and turbulence of the flow close to the actuation area.