Effects of throttling structures on cavitation flow and circumferential uniformity in a control valve

•The effect of throttling structure in the valve cage on flow characteristics is investigated.•The intensity and the location of cavitation which cause the different damage problems are clearly affected by the type of throttling stage.•The pressure uniformity along the circumference is closely concerned with throttling structure.•Some suggestions are given on the selection of throttle valve in practical applications. The valve serves as a pipeline attachment to relieve pressure, adjust and control the conveying medium. It is essential component in the fluid delivery system. As the fluid passes through the valve, the change of flow area results in dramatic changes in the fluid pressure, which leads to the occurance of cavitation and inevitably causes the damages to the valve body and the pipeline. Therefore, suppressing cavitation and minimizing its adverse impact are still of an important subject. In this study, the different throttling structures in an perforated cage are used to control flow. The effect on cavitation and the uniformity of flow are numerically investigated. The results show that the types of throttling stage clearly influence the intensity of cavitation. The different arranged types with the same number of stage and orifice diameter have the different location of cavitation. The forward two-stage throttling has the most severe cavitation in the downstream of the cage. In addition, the flow characteristics and the pressure uniformity are quite different with various throttling structures. Finally, some suggestions are given in the choice of a valve in the practical applications.