ANALYSIS OF CAVITATION CHARACTERISTICS IN THROTTLE VALVE WITH DIFFERENT STRUCTURE PARAMETERS

The pressure and cavitation characteristics of fluid through throttle valves with different structure parameters were investigated numerically using computational fluid dynamics. The mass flow rate, pressure drop, and the volume fraction of the vapor in the single and two-step throttle valve were computed. The cavitation regions were mainly distributed on the top of the valve rod and the corner of the valve seat in both of the different throttle valves. The size of cavitation region at the corner of the channel grows firstly, and then decrease with the decreasing opening degree. Furthermore, the lowest pressure region, as well as the area and strength of cavitation region, in the two-step throttle valve were smaller than a single one at the same opening degree. The formula for equivalent orifice area of throttle valve was derived, in order to explain the effect of opening degree. The results indicated that the two-step throttle has high anti-cavitation capability.