Numerical Simulation of Circulation Control for a Wing Section Using Coanda Jets

Abstract

Large-eddy simulations were carried out to describe the subsonic flow over a wing section, using Coanda-jet circulation control to augment lift. The section geometry consists of a modified supercritical airfoil, with a jet that is blown over a one-quarter circular cylindrical trailing-edge Coanda surface. Because the configuration does not include a slotted trailing-edge flap, the mechanical complexity and weight may be reduced. The computations correspond to an experimental investigation, which provides data for comparison. High-fidelity solutions were obtained to the unsteady three-dimensional Navier–Stokes equations at a chord-based Reynolds number of 4.75×105 and freestream Mach number of 0.1. Several angles of attack were considered, and solutions were obtained both with and without circulation control. In the control cases, three different jet-mass flow rates were simulated at each angle of attack. A grid-resolution study was carried out to assure numerical accuracy. Comparisons are made between the respective cases and with the experimental data, and features of the flowfields are characterized. It was found that Coanda-jet control was able to augment lift in excess of factors of three with reasonable amounts of jet-mass flow.