Analysis of laminar boundary-layer separation in retarded flow over bodies of revolution

Abstract

The laminar boundary-layer separation phenomenon is an interesting and important aspect of boundary-layer flows. It occurs in various physical situations because of a decrease in wall shear stress caused by retarded flow velocity, among other things. Flow separation can be prevented or delayed by utilizing bodies of revolution because the surface transverse curvature produces a favorable pressure gradient, which in turn increases the wall shear stress that keeps the flow attached to the surface. Bodies of revolution, whose body contours follow a power-law form, also play a vital role in delaying flow separation. Bodies of revolution of varying cross sections and involving surface transverse curvature are utilized to examine their effects on flow separation. In particular, a convex transverse curvature has been considered owing to its effects on the nature of the favorable pressure gradient, which delays the flow separation. A Görtler-type retarded flow velocity was considered in this study to investigate the flow separation process. A detailed analysis is provided to understand the flow separation by calculating the separation points under various assumptions. It has been observed that the body contour exponent n and the convex transverse curvature parameter k play an assistive role in the delay of boundary-layer separation even under the influence of strong retardation. The results are presented through various tables and graphs to highlight the role of the power-law exponent of external velocity m, convex transverse curvature parameter k, and body contour exponent n on the separation points.