Numerical simulation of two-dimensional plain flap ground effect based on NACA4412 airfoil

Abstract

Abstract Based on the NACA4412 airfoil, by solving a two-dimensional unsteady Reynolds-averaged N-S equation and using the k-ωSST model, this paper analyzes the influence of near-ground altitude change on different configuration flow fields under moving ground conditions and explores the variation law of wing pressure coefficient at different near-ground altitudes. The results show that the attraction of the upper airfoil is weakened by the GE (ground effect), the pressure of the lower airfoil is increased, and the upper and lower airfoils influence the lift change of the airfoil. With the decrease of near-ground altitude, at a certain AOA (angle of attack), the greater the flap angle is, the faster the suction loss on the upper wing surface is and the slower the pressure increases on the lower wing surface, and the lower the near-ground altitude corresponding to the minimum lift coefficient is. With the decrease of near-ground altitude, at a certain flap angle, the greater the AOA is, the faster the suction loss on the upper wing surface is and the slower the pressure increases on the lower wing surface, and the lower the near-earth altitude corresponding to the minimum lift coefficient is.