涡轮集气腔流动特性研究及流阻计算模型

Experimental Investigation on Flow Characteristics of Turbine Plenum Chamber and Flow Resistance Model

关键词:  空气系统  涡轮集气腔  流量分配  流阻损失  经验关系式

Key words:  Secondary air system  Turbine plenum chamber  Flow distribution  Flow resistance  Correlation equations

摘要:

为了探究航空发动机涡轮集气腔的流动特性，对4个主进气口、双排125个出流孔的涡轮集气腔出口流量分配规律和流阻系数进行了实验研究，重点分析了进出口压比、集气腔腔室高度等参数变化带来的影响。研究发现，正对主进气口的出流孔流量最大，而紧邻其两侧的周向出流孔流量明显减小。随着出流孔周向位置远离主进气口，出流孔流量迅速恢复并基本维持一个定值。但是位于每2个主进气口间1/2周向夹角位置，会出现最小的出流流量。实验结果表明，尽管周向上局部出流孔出现了极大和极小出流流量，但其仅为进口总流量的9.34%和3.29%。在本文实验参数范围内，随着进出口压比、集气腔高度的增加，通过集气腔的空气流量均变大，但并没有改变周向出流孔的流量分配规律。两者相比，集气腔高度带来的影响明显微弱。最终本文拟合得到了流阻损失系数同集气腔几何参数、进/出口气动参数之间的经验关系式，并将其应用于开发的一维空气系统集气腔元件中，为后续空气系统的设计与优化提供依据。

Abstract:

To obtain the flow characteristics of turbine plenum chamber such as the distribution of outflow and the flow resistance coefficient，a typical configuration，which has 4 air intakes and 125 exit holes located in two lines，was experimentally investigated. The ratio of inlet pressure to outlet pressure ，the chamber height were changed in experiments，then the flow characteristics of turbine plenum varying with these parameters were obtained. It was found that the holes directly facing the entrance had the maximum flow rate，while flow rate decreased greatly in the region very near those holes. As the holes’circumferential locations were away from the entrance，their flow rate quickly recovered and remained alomost the same. Meanwhile the minimum outflow rate was observed in the holes located circumferentially at the middle region between every two inlet holes. However these maximum and minimum mass flow rates were only 9.34% and 3.29% of the total flow，respectively. It was also found that with the increasing of inlet pressure and chamber height，the mass flow rate going through turbine plenum chamber increased，while the distribution of circumferential outflow did not change. Compared against inlet pressure，chamber height affected flow characteristics much more faintly. Finally correlation equations about flow resistance were concluded in this paper，which took geometrical parameters and inflow/outflow aerodynamic parameters into account. One dimensional component of turbine plenum chamber for secondary air system was also developed based on those correlation equations，which can support the design and optimization of secondary air system.