CONVECTIVE FLOW OF POWER-LAW FLUIDS ACROSS A PAIR OF TANDEM CIRCULAR CYLINDERS IN CONFINED ARRANGEMENT

Abstract

In this work the steady flow of power law fluids across a pair of circular tandem cylinder has been studied numerically. The governing equations has been solved by FVM based solver FLUENT. In this work the effects of Power Law Index (0.2 to 1.8), Reynolds Number (1 To 40), Prandtl Number (1 to 100), Gap Ratio (2 to 10) and Richardson number (0 to -3) and their effect on local ang global characteristics such as streamlines, vorticity profile, isotherm velocity between two cylinder and pressure coefficient has been studied numerically. With increase in the shear thinning effect that is increasing the n the separation of flow took a longer time whereas the early flow separation occurred in case of power law index equal to 1 or less than 1.the pressure coefficient on the surface of cylinder showed a close relation with power law index, Reynolds Number and gap ratio but the effect of Richardson Number did not alter it significantly. The nusselt Number showed a close correlation with the Reynolds Number and Prandtl Number. The changes in Prandtl Number affected Nusselt Number significantly but it’s effect on other coefficient such as Drag Coefficient and pressure coefficient were not significant precisely it did not alter these values a little bit but when Richardson Number Became negative it showed a little change. The drag coefficient values of individual cylinders came out to be smaller than the values of single Cylinder. The downstream cylinder was critically afeected by the changes in Gap Ratio. As the gap ratio was kept smaller i. e. 2 or four the effects of upstream cylinder was high on downstream cylinder but for higher values of gap ratio the downstream cylinder started behaving like individual circular cylinder. The effect of change of Richardson number can be easily seen in the streamline, vorticity and isotherm profiles.