Effects of chemical reaction, heat and mass diffusion in natural convection flow from an isothermal sphere with temperature dependent viscosity

摘要

Purpose - To investigate the effects of chemical reaction on natural convection heat and mass transfer from a sphere with temperature dependent viscosity. Design/methodology/approach - The governing boundary layer equations are transformed into a non-dimensional form and the resulting nonlinear system of partial differential equations are reduced to local non-similarity boundary layer equations, which are solved numerically by very efficient implicit finite difference method together with Keller box scheme. Findings - The effects of chemical reaction, the skin-friction coefficients, surface heat transfer rates, velocity and concentration distribution decrease as well as the mass transfer rates and temperature distribution increase within the boundary layer. Research limitations/implications - The investigation is valid for steady two-dimensional laminar flow. The concentration of the reactant is maintained at a constant value and the sphere is isothermal. An extension to unsteady flow with temperature dependent thermal conductivity is left for future work. Originality/value - This result provides guidance to engineers about heat and mass transfer with the effects of chemical reaction from isothermal spherical surface.