钟形口流量管入口段速度型面研究

Research on velocity profile of entrance section of bell-mouth flow tube

航空发动机试验中通常使用钟形口流量管对进气流量进行试验。在测量过程中,针对测点布置不准确造成测量结果不准确及测量成本增加的问题,开展了管内入口段测量截面上的速度分布情况研究。本文分析了钟形口流量管的测量原理以及湍流状态下管内气流的流动状态,研究了测量截面沿直径方向上速度的变化,建立了管内径向速度分布的数学模型,最终通过试验与仿真的方法对速度分布模型进行了分析与验证,为准确得到管内空气流量提供了一种基于速度分布模型的新方法,即通过试验测得流量管测量截面上少数点的数据信息得到管内速度分布模型,从而得到更准确的管内空气流量值。研究结果对进气流量的测量以及发动机性能的评定试验有重要意义。

Bell-mouth flow tube is usually used to test the intake flow in aero engine tests.Aiming at the problem of the inaccurate measurement results and the increased measurement cost caused by the inaccurate layout of measuring points in the process of measurement,the velocity distribution on the measurement section of the inlet section of the tube is studied.The measurement principle of the bell-mouth flow tube and the flow state of the airflow in the tube under the turbulent flow state are analyzed in this paper.The variation of velocity along the diameter direction on the measurement section is studied,and the mathematical model of the radial velocity distribution in the tube is established.Finally,the velocity distribution model is analyzed and verified by the methods of experiment and simulation.A new method based on velocity distribution model is provided for accurately obtaining the air flow in the tube,that is,the data information of a few points on the measurement section of the flow tube is measured through the test to establish the velocity distribution model,so that a more accurate air flow value in the tube is obtained.The research results are of great significance to the measurement of intake air flow and the evaluation test of engine performance.