Heat transfer phenomenon in a retarded boundary layer over a moving continuous cylinder

Abstract

The phenomena of flow separation on a surface of finite length is analogous to boundary layer flows caused by retarded motion of continuous surfaces, which ultimately seize at some downstream position and increase drag on aerodynamic vehicles. According to the literature, a stationary surface of finite length will generate a boundary layer that is less energetic than one that is developed over a moving continuous surface. This means that a moving continuous surface is preferred to a stationary surface of finite length for the sustainability of the transport phenomena in such a retarded flow, which must eventually meet the flow separation. Therefore, the goal of this study is to conduct a heat transfer analysis in a delayed laminar boundary layer generated by a moving continuous cylinder with a constant radius. Wall temperature of uniform nature is considered in this investigation. In most of the boundary layer flows the self-similarity of the flow does not persist because of choosing the reference velocity of the desired character. Thus, the problem becomes non-similar. In general, the non-similarity of a flow may appear due to various aspects of the problem such as the retarded nature of the reference velocity, the surface temperature, the curvature of the body, etc. Surface transverse curvature imparts favorable consequences on the separating boundary layer and hence on the seizing flow character. The purpose of this investigation is to determine how TVC and the wall velocity power index affect temperature profiles, the local Nusselt number , the thickness of the thermal layer, and the thermal diffusivity of heat in a retarded boundary layer. In addition to this, the influence of Prandtl number and Stanton number has also been investigated. The numerical solution is computed using an implicit finite difference scheme, commonly known as the Keller-Box scheme in MATLAB scientific computing software Investigations reveal that the TVC assists the thermal transport by enhancing the rate of heat transfer and the length of the convectively heat transferring region (starting from the leading edge to the location where the flow gets seized) by increasing the longitudinal region of flow (starting from the leading edge to the location where the flow gets seized) on the surface. The surface wall velocity power index acts to decrease the temperature distribution and reduces the heat transfer rate at the surface. Further, the Prandtl number reduces the thermal boundary layer thickness and the Stanton number but enhances the local Nusselt number.