Entropy generation in a vertical concentric channel with temperature dependent viscosity

Present research efforts mainly focus oil the nature of irreversibility, ill terms of entropy generation, inside a vertical cylindrical annulus. Laminar mixed convective flow of Newtonian fluid is considered with variable (temperature dependent) viscosity. Tile temperature dependent nature of viscosity is assumed to follow an exponential model. We seek for the closed form of analytical solutions by solving the simplified governing equations in cylindrical coordinates. Isothermal boundary condition is applied. Analytical expressions for the velocity and temperature are, derived which essentially expedite to obtain expressions for local and average entropy generation in the annular space. (C) 2002 Elsevier Science Ltd.