The effect of temperature-dependent viscosity on free-forced convective laminar boundary layer flow past a vertical isothermal flat plate

Abstract

The effect of a temperature-dependent viscosity on an incompressible fluid in steady laminar free-forced convective boundary layer flow over an isothermal vertical semi-infinite flat plate is studied. The local similarity solution is used to transform the system of partial differential equations, describing the problem under consideration, into a boundary value problem of coupled ordinary differential equations and an efficient numerical technique is implemented to solve the reduced system. Numerical calculations are carried out, for various values of the dimensionless parameters of the problem, which include a Prandtl number, a mixed convection parameter and a viscosity/temperature parameter. The results are presented graphically and the conclusion is drawn that the flow field and other quantities of physical interest are significantly influenced by these parameters. In particular, it is concluded that when the viscosity of a working fluid is sensitive to the variation of temperature, care must be taken to include this effect, otherwise considerable error can result in the heat transfer processes. In the literature, such care is not always evident.