Bodewadt flow of Bingham fluid over a permeable disk with variable fluid properties: A numerical study

摘要

This study is primarily motivated to explore the onset of fluid yield stress on the Bodewadt flow involving Bingham fluid whose viscosity coefficient admits an inversely linear temperature dependency. Accompanying heat transfer process is studied by assuming isothermal surface temperature. A similarity solution is presumed which results into a system of coupled non-linear equations with three unknowns. Numerical solutions reveal that ignoring viscosity variation with temperature can lead to inaccurate calculations of skin friction coefficient and Nusselt number, which are important quantities from engineering viewpoint. For pure Bodewadt flow, axial flow accelerates and radial flow reduces when case of constant fluid properties is approached. In addition, a considerable growth in cooling rate of the surface is detected whenever suction velocity becomes higher. Both two-and three-dimensional streamlines are computed which reveal that Bingham fluid assumption combined with variable viscosity markedly affects the flow situation.