Dynamic characteristics analysis of floating needle valve under different operating parameters

With its millisecond-scale response capability, the attitude and orbit control valve allows for repeated startup and shutdown of the engine. Investigating the valve's dynamic performance is critical to enhancing the maneuvering capability and control precision of the entire attitude and orbit control engine system. This paper experimentally investigates the influence of different working parameters on its dynamic response and provides an accurate and rapid prediction method for its dynamic response, which is highly important for design purposes. Firstly, a cold gas test system for the attitude and orbit control floating valve was established, and its dynamic response curve was obtained. The effects of different working pressures and actuation frequencies on its response time were studied. Secondly, the existing model of the floating valve's dynamic response process was optimized by coupling the flow loss coefficient. The research results show that: experiments indicate that a decrease in operating pressure reduces the opening time but increases the closing time of the floating valve, which is attributed to the increased flow rate through the jet orifice per unit time caused by higher pressure. Reducing the switching time can increase the number of on-off cycles; meanwhile, it leads to a shorter opening time and a longer closing time, which is due to the prolonged stable operation time. When the switching time is reduced to 30 ms, the floating valve fails to open. The calculation error of the dynamic characteristics of the theoretical model is within 10 %.