Numerical Investigation on Cavitation Occurrence in a 2/2 Proportional Valve

Cavitation is a major issue in hydraulic systems that degrades the life of the valve by damaging its walls and the piping downstream through implosions of vapor bubbles. Over the years, many studies have been conducted to raise a solution to such problem. Eventually, the solution can be divided into two categories: changing the process parameters or modifying the valve itself. This thesis focuses on the second type of solution where a prototype valve designed by HTS S.r.l. is analyzed and compared in terms of vapor presence to a commercial 2/2 proportional valve that is prone to cavitation using the commercial computational fluid dynamics (CFD) software ANSYS Fluent, while keeping the process parameters constant. The presence of cavitation in these two valves is evaluated by two different perspectives to cover the principle working conditions of the system: opening of the valve and direction of the flow. In total, four openings (5, 10, 20 and 40-millimeter) and two directions of flow (converging and diverging) have been investigated. In addition, the performance of a new valve housing that has been developed to prevent cavitation from extending to the outlet section has been evaluated.