Hydraulic Throttle Cavitation Suppression Method Based On Pressure Feedback

Cavitation and cavitation erosion are always the serious problem in hydraulic system. As high pressure-high speed hydraulic technology and water hydraulic technology are developing, it is too important to wait to solve these problems. Based on the research about the theory of cavitation and restraining cavitation erosion, author puts forward an idea that feeding back the outlet-pressure to the orifice to improve the static pressure of the downstream of orifice and decrease the area of low-pressure, and it may lead the level of cavitation and cavitation erosion to reduce.The main purpose of this article is to check whether outlet-pressure feedback can limit cavitation and reduce cavitation erosion and to study the performance of the relevant structure on limiting cavitation. Firstly, based on the theory of cavitation, cavitation dynamics and research on cavitation cloud, a one-dimensional cavitation cloud model was built and the main parameters were estimated reasonably; secondly, a structure was designed according to the mentioned idea; thirdly, flow information pressure and velocity obtained from FLUENT calculating were used to solve the one-dimensional cavitation cloud model. By this numerical method, whether the inlet-pressure feedback structure has an effect on limiting cavitation and the performance of the structure on limiting cavitation were studied under different operating condition; finally, whether the inlet-pressure feedback structure has an effect on limiting cavitation and the performance of the structure on limiting cavitation were studied under different operating condition according to the experimental analysis. What's more, the power spectrum of fluctuating pressure in valve chamber was selected as standard to evaluate the degree of cavitation.Both numerical method and experimental analysis method uniformly certified that outlet-pressure feedback method do have an effect on limiting cavitation. Under different operating condition, the results of the performance of limiting cavitation obtained from numerical method and experimental analysis method respectively are nearly same, despite that there are some differences between the results obtained from numerical method and experimental analysis method respectively. With inlet-pressure increasing, the capacity of the structure's limiting cavitation was enhanced gradually, but when the inlet-pressure increased to a certain value, the capacity of the structure's limiting cavitation started to decrease; With outlet-pressure increasing, the capacity of the structure's limiting cavitation was enhanced gradually.