Influence of Thermal Radiation on Unsteady Flow over an Expanding or Contracting Cylinder with Thermal-Diffusion and Diffusion-Thermo Effects

Abstract

An analytical study is conducted to present thermal radiation, Dufour, and Soret effects on unsteady viscous flow over a contracting cylinder. The coupled nonlinear partial differential equations are transformed into a system of coupled nonlinear ordinary differential equations by using a suitable similarity transformation. The homotopy analysis method (HAM) and HAM with a nonhomogeneous term are employed to obtain analytical solutions for the system of coupled nonlinear ordinary differential equations. A significant reduction in the averaged square residual error is obtained when the nonhomogeneous term is introduced. A comparison between analytical and numerical solutions is presented for validation. The effects of various emerging parameters on flow variables are discussed. It is found that the temperature distribution increases with an increase in Dufour number, but decreases with an increase in Soret number. The concentration distribution decreases for a given increase in the Dufour number, but increases with an increase in Soret number.