翼形の乱れ促進体を挿入したチャネル乱流の流動と熱伝達

概要

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An experimental study is performed for a turbulent channel flow obstructed with an airfoil type turbulence promoter. The Reynolds number ranges from 2.1×104 to 8.4×104, and the clearance between the wall and the promoter is changed in three steps. The total performance evaluation between heat transfer and pressure drop is estimated under the conditions of an equal pumping power. PIV is used for the measurements of velocity profiles, turbulent intensity and Reynolds shear stress. When the clearance is small, the heat transfer coefficient is augmented by the increase of turbulence intensity. The high performance is obtained by inserting the airfoil type turbulence promoter. At large clearance, the vortex shedding from the trailing edge of promoter is observed and high turbulence region is observed near the promoter. However, the excessive turbulence is rapidly decreased in the downstream direction, and the heat transfer coefficient becomes low value compared with that of the small clearance.