Theoretical Analysis of Unsteady Flow Between Two Stretching Cylinders with Variable Physical Properties

This study investigates unsteady flow between two stretching cylinders with variable thermal conductivity and viscosity. Using similarity transformations, governing equations for motion, energy, and mass transport are reduced to ordinary differential equations. Solutions are obtained via Homotopy Analysis Method (HAM) and compared with BVP4c numerical package. Results demonstrate excellent agreement and show how unsteadiness parameters, Prandtl number, Brownian motion, and Lewis number affect velocity, temperature, and concentration profiles.