Transient free-convective flow of reactive viscous fluid in vertical tube

The problem of fully-developed transient free-convection flow of viscous reactive fluid in a vertical tube is analyzed both analytically and numerically. The study reports the effect of several operating parameters on the flow hydrodynamics and thermal characteristics. The solutions for transient state velocity and temperature fields are obtained by implicit finite difference method. To check the accuracy of the numerical solution steady-state solutions for temperature field and velocity field are obtained by using perturbation series method. Skin-friction and Nusselt number at the surface of tube are determined. The significant results from this study are that both velocity and temperature increase with the increase in the value of reactant consumption parameter and non-dimensional time until they reach steady-state value. The results also indicate that it takes longer time to attain steady-state in the case of water than air. During the course of computation, it was observed that the analytical and numerical solutions agree very well at large value of time. (C) 2011 Elsevier Ltd. All rights reserved.