Effect of oblique and non-uniform wall suction and injection on the characteristics of flat-plate boundary layer

Abstract

This paper studied active flow control techniques like suction and injection to control the boundary layer. The steady, incompressible, and two-dimensional flow passes over the flat plate, and boundary layer formation starts at the plate’s leading edge. The flow is uniform and parallel to the surface of the plate at the leading edge. The suction or injection has been applied at a distance of 0.25m from the leading edge of the flat plate to convert the problem more realistic and continue up to the trailing edge. The discrete slots or porous portion is available downstream after 0.25m for mass transpiration. A steady, two-dimensional, incompressible Navier-Stokes equations are solved using OpenFoam software using a simpleFoam solver with appropriate boundary conditions. For non-uniform suction and injection, considered two variations, the first one is linear variation, and the second is quadratic variation. However, for oblique non-uniform suction/injection variations five angles (θ=300, 600, 900, 1200, and 1500) are proposed. The codedFixedValue type code is developed for oblique non-uniform wall suction and injection in the velocity boundary condition. The results show that the wall-normal component of oblique or vectored suction/injection velocity (Vw), non-uniform suction/injection profiles, suction/injection intensity, and suction/injection angles significantly affect the boundary layer characteristics. A detailed discussion has been presented in the results and discussion section.