冷却空气管供气腔脉冲射流流动响应特性实验研究

Experimental Investigation on Flow Response Characteristics of Pulsed Jet Through Cooling Air Pipe Plenum Chamber

关键词:  航空发动机  控制系统  冷却空气管  脉冲射流  响应特性  容腔效应  流容

Key words:  Aeroengine  Control system  Cooling air pipe  Pulsed jet  Response characteristics  Cavity effects  Flow capacity

摘要:

为了探究脉冲射流经航空发动机主动控制系统中冷却空气管内的流动响应规律，对单排40个出流孔的冷却空气管内的脉冲射流流动响应特性进行了实验研究。同时，引入了响应时间、迟滞时间和出流速度系数三个评价参数，对脉冲射流在冷却空气管内的响应特性进行定量分析。实验重点分析了脉冲频率f（1~20Hz）、进口雷诺数Re（5×10³~2×10⁴）等参数变化对流动响应特性带来的影响。研究发现，在一个脉冲周期内，冷却空气管出流速度的响应时间和迟滞时间沿程逐渐增加，出流速度系数沿程变化不大。在实验参数范围内，f和Re增大，冷却空气管出流响应时间、迟滞时间所占脉冲周期的比例和出流速度系数逐渐增大。f，Re越大，冷却空气管内压力越大，流容越小。

Abstract:

To obtain the pulsed jet flow response characteristics of cooling air pipe plenum chamber in the aero-engine active control system such as the characteristics of flow response， a typical configuration， which has 40 exit holes located in one lines， was experimentally investigated. Three evaluation parameters， including the response time， the lagging time， the outflow velocity coefficient were introduced to quantitatively analyze the response characteristics of the pulsed jet in the cooling air pipe plenum chamber. The inlet Reynolds number （5×10³~2×10⁴）， the impulse frequency （1~20Hz） were changed in experiments， then the flow response characteristics of pulsed jet varying with these parameters were obtained. It was found that， the response time， the lagging time increased gradually along the cooling air pipe and the outflow velocity coefficient had a less variation along the cooling air pipe mainly. Among the current research conditions， the ratio of response time and lagging time to the pulse period and the outflow velocity coefficient gradually increased with the increasing impulse frequency and inlet Reynolds number. As impulse frequency and inlet Reynolds number increased， the pressure in the cooling air pipe gradually increased and the flow capacity in the cooling air pipe gradually decreased.