Entropy Generation for Nonisothermal Fluid Flow: Variable Thermal Conductivity and Viscosity Case

This paper investigates the entropy generation of a nonisothermal, incompressible Newtonian fluid flowing under the effect of a constant pressure gradient in plane Poiseuille flow. The effects of variable viscosity and thermal conductivity are also included. The viscosity and thermal conductivity of the fluid exhibit linear temperature dependence and the effect of viscous heating is included in the analysis. Channel walls are kept at constant temperatures. Velocity, temperature, and entropy generation profiles due to heat transfer and fluid friction are plotted. The effects of Brinkman number, Peclet number, pressure gradient, viscosity, and thermal conductivity constant on velocity, temperature, and entropy generation number are discussed. Discretization is performed using a pseudospectral technique based on Chebyshev polynomial expansions. The resulting nonlinear, coupled boundary value problem is solved iteratively using Chebyshev-pseudospectral method.