Effect of rotation on forced turbulent flow and heat transfer in a ribbed U-duct
V.V. Ris, A.M. Levchenya, S.A. Galaev, I.A. Ignatiev
Peter the Great St. Petersburg Polytechnic University, St. Petersburg, Russia
Keywords: U-duct, ribbed sides, turbulent flow, heat transfer, numerical modeling, effects of rotation
Abstract
The paper presents a method and results of simulation for turbulent air flow and heat transfer in a U-shaped square duct with straight sections and with two ribbed opposite sides. For a flow with Reynolds number of 6×104 and Prandtl number of 2.5, the numerical solution method was validated by comparing the calculated and experimental data on local heat and mass transfer in geometrically identical U-ducts; the ribs inclined to the duct axis by 45 and 60 deg. For one of these ducts with the rib inclination angle of 45 deg (at the same Reynolds number and Prandtl number of 0.71), the flow pattern and heat transfer were calculated for a stationary state and for a mode with rotation (with the rotation parameter values of 0.1 and 0.25). The rotation axis is perpendicular to the duct axis and parallel to the duct bended plane. The calculation data for the U-shaped duct are compared with the calculation data for a fully developed (periodic) flow and heat transfer for a straight-and-ribbed duct. It is shown that for a U-duct, the effect of rotation has a positive influence on heat transfer enhancement.
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