Influence of Aeleron Position on Transonic Flow Around an Aerodynamic Profile

Transonic flow past the Dsma523b airfoil equipped with an aileron is studied in the free-stream Mach number range from 0.81 to 0.85. The airfoil angle of attack varies from –0.5° to 2°. The numerical solution of the Reynolds-averaged Navier–Stokes equations is found using the finite volume method using the Ansys CFX software package. The k−ω SST and BSL Reynolds Stress turbulence models are used. They yield similar results. At small angles of attack from –0.5° to 0.5°, the airfoil lift coefficient decreases sharply with increasing free-stream Mach number if the aileron is not deflected. Upward deflection of the aileron by 4° results in a lift coefficient that depends weakly on the Mach number. In the lower part of the studied range of Mach numbers, an upward aileron deflection of several degrees causes anomalously large changes in lift. Conversely, in the upper part of the Mach number range, these changes are anomalously small, and at an aileron deflection of 1° to 3°, they are completely absent. Increasing the angle of attack of the airfoil to 2° leads to the disappearance of this anomaly. The two anomalous regimes correspond to different sizes and locations of the supersonic zones adjacent to the airfoil.