Laminar separation point of flow on surface of symmetrical airfoil

Abstract

A Numerical-Analytical Method and Shvets’s method for calculating separation point position of the laminar boundary layer on a surface of an airfoil are used. An approximate Shvets’s method allows calculating of the separation point position of the laminar boundary layer if the velocity distribution on the surface of two-dimensional body is known. The velocity distribution on the surface of the airfoil is obtained in the model of an ideal incompressible fluid. It is found that main contribution to the position of the separation point makes through relative airfoil thickness. The thicker the airfoil, the closer to the leading edge of the airfoil is located separation point. The relative coordinate chordwise location of the airfoil maximum thickness affects to position of the separation point only for thick airfoils. The increasing of the relative coordinate of the maximum thickness for thick airfoil leads in displacement of the separation point to trailing edge of the airfoil. With increasing the angle of attack separation point, which located on upper surface of the airfoil quickly moves to leading edge and separation point on lower surface of the airfoil moves slowly to trailing edge.