玉形弁下流における流れ加速型腐食（流れ場の測定と数値計算）

抄録

In order to evaluate the effects of flow field on flow accelerated corrosion (FAC), the flow field downstream from a globe valve was measured using laser Doppler velocimetry (LDV) and particle image velocimetry (PIV) and was simulated by unsteady RANS (URANS). The globe valve was a cage guided type and a column between cage windows was placed perpendicular to the flow direction. The diameter of a downstream pipe was 50 mm, and mean cross-sectional velocity was about 2 to 6 m/s. Swirl flow with twin vortices was visualized by PIV and simulated by CFD in the cross section downstream from the globe valve. The flow-directional velocity profiles measured by LDV and simulated by URANS under different velocity conditions coincided with each other when profiles were normalized by the mean velocity. It indicated flow structure downstream from the globe valve did not depend on the flow velocity. Predicted wall shear stress and turbulent kinetic energy adjacent to the wall were higher on the lower wall than those on the upper wall.