Entropy generation in convection over an inclined backward-facing step with bleeding

Abstract

The current work investigates entropy generation around an inclined backward-facing step under bleeding conditions using suction/blowing. The entropy generation is due to heat transfer and fluid flow in forced convection laminar flow in a duct with inclined step. The set of governing equations containing conservations of mass, momentum and energy are solved numerically to calculate the velocity and temperature profiles inside the flow domain. Because of the complex flow geometry, conformal mapping is used to generate an orthogonal grid by means of the Schwarz-Christoffel transformation. The governing equations are transformed into the computational domain and the discretized forms of the governing equations are obtained by the control volume method. In the numerical computations, the SIMPLE algorithm is used for the pressure-velocity coupling. Numerical expressions, in terms of entropy generation number (Ns), Bejan number (Be) and Nusselt number (Nu) are derived in dimensionless forms using velocity and temperature profiles. The effects of step inclined angle and bleed coefficient on the entropy generation number, Nusselt number, Bejan number and friction coefficient are presented. Key words: Entropy generation, bleeding, inclined backward step.