UNSTEADY FLUID FLOW AND HEAT TRANSFER OVER A TRIANGULAR CYLINDER IN CROSS-FLOW

Abstract

Two-dimensional CFD simulation of flow and heat transfer over an equilateral triangular cylinder is carried out in this dissertation work. Reynolds number range of study was 5O<Re<150, in steps of 10. Fluid was air, with Prandtl number, Pr=0.71. Computational grids are generated using GAMBIT. Governing equations are solved by Finite Volume Method (FVM) based CFD package FLUENT (6.3). Effect of Reynolds number on periodicity is studied by obtaining time averaged drag coefficient (Co ), Strouhal number (St), and root mean square lift coefficient (C1 ,-„,$). Strouhal number increases with Reynolds number, it attains a flat value at high Reynolds numbers, a local maxima at Re=140 is also seen. Drag coefficient and root mean square lift coefficient are strong functions of Reynolds number, both increase with Reynolds number. Time and space averaged Nusselt number ((Nu )) also increases with Reynolds number. Contour plots of stream function, pressure, velocity magnitude and temperature give better visualization of flow and heat transfer. Results of present study are in good agreement with literature. Correlations for Strouhal number, time and space averaged Nusselt number, root mean square lift coefficient and drag coefficient are also presented.