高集成度节流嘴流动特性研究OA北大核心CSTPCD

In response to the small size of throttling nozzles used in aircraft hydraulic control systems and difficulty for conventional experimental methods to obtain the flow parameters of the internal flow field of the throttling nozzle,the aviation kerosene was used as the working fluid to numerically simulate the resistance-flow characteristics of two types of throttling nozzles,and the model was experimentally verified.The internal flow field of Type Ⅰ throttling nozzle was obtained under flow rates of 1.25 L/min and 2.22 L/min,and at temperatures of 80℃and 20℃;And the internal flow field of the Type Ⅱ throttling nozzle was obtained under flow rates of 0.37 L/min and 0.56 L/min,and at temperatures of 80℃and 20℃.The results indicate that the pressure of jet fuel basically does not change when flowing through a straight pipe and a safety filter screen,with the pressure drop mainly occurring at the orifice and the filter holes,and the pressure drop at the orifice is more than two times that at the filter holes.The flow field distribution in the throttle channel remains similar at different flow rates,but there is difference in values of flow parameters such as pressure,velocity,and turbulent energy.The flow at the orifice and filter holes exhibits higher turbulent energy due to intense mixing of fluid particles and large velocity fluctuations at these locations.With constant temperature and outlet pressure,a higher flow rate results in a greater pressure drop at the inlet and outlet of the throttle.Temperature variations affect the density of jet fuel,leading to smaller pressure drops at the inlet and outlet of the throttle at lower temperatures under the same mass flow rate.The research results can provide theoretical guidance for the design of throttles in aircraft hydraulic control systems.