Investigation of flow characteristics in the U-shaped throttle valve

Experimental and numerical analysis of cavitation flow in the U-shaped throttle valve is presented in this article. Cavitation flow has been analyzed numerically using the volume of fluid model while the pictures are captured by a high-speed camera. The results reveal that the distribution of pressure is extremely inhomogeneous, and the pressure drop zone is mainly distributed in the narrow U-shaped groove. Cavitation bubble occurs around the orifice and develops continuously since the pressure drops. The nascent, developed, and collapsed zone of the cavitation within U-shaped throttle valve are also presented. In addition, a high-speed jet flow is formed when the oil flows out the U-shaped orifice, a vortex appears and cavitation bubbles appear. Then, cavitation evolution and the effect of back pressure and the valve opening on cavitation behavior have been discussed. Increasing back pressure will weaken the cavitation intensity and suppress the cavitation effectively. The valve opening also affects the cavitation flow and performance of the U-shaped throttle valve. With the increase of valve opening, cavitation area first increases and then decreases. The results and conclusions presented in this article give the basis for better understanding the cavitation phenomenon in a throttle valve.