NUMERICAL INVESTIGATION OF ENTROPY GENERATION IN LAMINAR FORCED CONVECTION FLOW OVER INCLINED BACKWARD AND FORWARD FACING STEPS IN A DUCT UNDER BLEEDING CONDITION

Abstract

A numerical investigation of entropy generation in laminar forced convection of gas flow over a recess including two inclined backward and orward facing steps in a horizontal duct under bleeding condition is resented. For calculation of entropy generation from the second law of hermodynamics in a forced convection flow, the velocity and temperature istributions are primary needed. For this purpose, the two-dimensional artesian coordinate system is used to solve the governing equations which are conservations of mass, momentum and energy. These equations are solved numerically using the computational fluid dynamic techniques to btain the temperature and velocity fields, while the blocked region method s employed to simulate the inclined surface. Discretized forms of these quations are obtained by the finite volume method and solved using the IMPLE algorithm. The numerical results are presented graphically and the ffects of bleeding coefficient and recess length as the main parameters on he distributions of entropy generation number and Bejan number are nvestigated. Also, the effect of Reynolds number and bleeding coefficient on total entropy generation which shows the amount of flow irreversibilities is presented for two recess length. The use of present results in the design process of such thermal system would help the system attain the high performance during exploitation. Comparison of numerical results with the available data published in open literature shows a good consistency.

Keywords

Dates

  • Submission Date2011-05-31
  • Revision Date2012-01-20
  • Acceptance Date2012-02-08

DOI Reference

10.2298/TSCI110531026A

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Volume 18, Issue 2, Pages479 -492