摘要
针对飞机液压控制系统用节流嘴尺寸较小,常规试验手段难以获得节流嘴内部流场的流动参数的情况,以航空煤油为工质,对两种构型的节流嘴进行了阻力-流量特性的数值仿真,并对模型进行了试验验证,获得了Ⅰ型节流嘴在流量为1.25 L/min和2.22 L/min,温度为80℃和20℃条件下的内部流场,以及Ⅱ型节流嘴在流量为0.37 L/min和0.56 L/min,温度为80℃和20℃条件下的内部流场。结果表明:航空煤油在直管内和安全滤网内流动时,压力基本不变,压降主要在节流孔和安全网滤孔处产生,且节流孔处的压降为安全网滤孔处压降的2倍以上;不同流量下的节流嘴通道流场分布相似,只是压力、速度、湍动能等流动参数的数值大小有差异;节流孔和滤孔处的湍动能较大,原因为该处的流体质点之间剧烈掺混,速度脉动大;保持航空煤油的温度和出口压力不变,航空煤油的流量越大,节流嘴出入口的压降越大;温度变化导致航空煤油的密度变化,相同质量流量下,温度越低,节流嘴出入口压降越小。研究结果可为飞机液压控制系统用节流嘴的设计提供理论指导。
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.
作者
徐轩
安理会
李文霞
符江锋
郑学波
XU Xuan;AN Lihui;LI Wenxia;FU Jiangfeng;ZHENG Xuebo(Xi'an Engine Control Technology Company of Aero Engine Corporation,Xi'an 710077,China;College of Power and Energy,Northwestern Polytechnical University,Xi'an 710072,China;School of Energy and Electrical Engineering,Chang'an University,Xi'an 710064,China)
出处
《流体机械》
CSCD
北大核心
2024年第7期42-48,共7页
Fluid Machinery
基金
陕西省重点研发计划高校联合重点项目(2021GXLH-01-16)
航空发动机及燃气轮机基础科学中心项目(P2022-B-V-003-001)
国防基础科研项目(JCKY2022607C002)
中国航发产学研合作项目(HFZL2022CXY013)。
关键词
飞机液压系统
节流嘴
流阻
仿真
aircraft hydraulic system
throttling nozzle
flow resistance
simulation
