Flow field characteristics of the U-shaped throttling constant differential pressure valve

As the research object of a U-shaped throttling constant differential pressure valve, numerical simulation study was carried out based on three-dimensional modeling technology, the preliminary model of pressure valve was designed, then structured grid was divided by using periodic mesh. Finally the inner-flow performance was simulated and the flow field of the pressure valve was analysed, and then the performances between different pressure valve's output opening were compared. The inner flow state indicates: under different flux and opening, the pressure gradient is large because of area change, pressure drop is mainly concentrated around the break zone, and some low-speed ranges and secondary vortex flows move around. The predicted performance of the external characteristics shows that: for both different flow rate and different opening degrees at the same flow conditions, pressure difference is maintained at around 0.9 MPa, meeting the design requirements. And pressure change has a similar trend at different degrees of opening, the greater opening means the larger pressure, and low flow is accordingly faster.