Boundary layer flow over a yawed cylinder with variable viscosity: Role of non-uniform double slot suction (injection)

摘要

Purpose - The purpose of this paper is to study the effect of non-uniform double slot suction (injection) into a steady laminar boundary layer flow over a yawed cylinder when fluid properties such as viscosity and Prandtl number are inverse linear functions of temperature. Non-similar solutions have been obtained from the starting point of the streamwise co-ordinate to the exact point of separation. Design/methodology/approach - The governing equations are tackled by the implicit finite difference scheme in combination with the quasi-linearization technique. Quasi-linear technique can be viewed as a generalization of the Newton-Raphson approximation technique in functional space. An iterative sequence of linear equations is carefully constructed to approximate the nonlinear equations for achieving quadratic convergence and monotonicity. The quadratic convergence and monotonicity are unique characteristics of the quasilinear implicit finite difference scheme, which makes this scheme superior to built-in iteration of upwind or finite amplitude techniques. Findings - The results indicate that the separation can be delayed by non-uniform double slot suction and also by moving the slot downstream. However, the effect of non-uniform double slot injection is just the opposite. Yaw angle has very little affect on the location of the point of separation. Originality/value - This analysis is useful in understanding many boundary layer problems of practical importance for undersea applications, for example, in suppressing recirculating bubbles and controlling transition and/or separation of the boundary layer over submerged bodies.