基于四孔压力探针技术的涡轮转子出口流场测量

Turbine Rotor Outlet Flow-Field Measuring with Four-Hole Pressure Probe

利用位移机构移动四孔压力探针,对小展弦比涡轮转子出口不同试验状态下的流场进行了测量。试验前对四孔压力探针进行了标定,试验中利用同步锁相技术进行数据采集,采用等相位平均法进行数据处理,再通过插值算法对探针压力数据做进一步处理,准确得到了转子出口具有周期特性的马赫数、偏转角、俯仰角、总压、静压、速度等流场参数。测量结果清楚表明:泄漏流区域的速度低,对应的相对总压小,损失大;间隙大时,泄漏流显著,导致气流亏转,对应的静压高,膨胀程度小于主流。

A four-hole pressure probe driven by traverse control equipment was used for the measurement of the three-dimensional flow-field of the low-aspect ratio rotor outlet in an axial turbine.The four-hole pressure probe was calibrated before the tests. The data were acquired by using phase-locked technology, and the equiphase time-average method and the input-value arithmetic were employed for the data process- ing. As a result, flow-field parameters like Mach number, deflection angle, pitching angle, total pressure, static pressure, velocity were obtained which were obviously periodic due to the rotor. The measuring results indicate that the velocity in the leakage flow region is very low, relative total pressure is low and the loss is high. With bigger tip clearance, the leakage flow is relatively stronger, which leads to flow under-turning. The static pressure in the leakage flow is higher and the expanding degree is smaller than that in the main flow.