透平内部非稳态流动试验研究进展

Experimental Research Progress on InternalUnsteady Flow of Turbine

关键词:  透平  内部流场  试验研究  非稳态流动  动静干涉  二次涡  尾迹  综述

Key words:  Turbine  Internal flow field  Experimental research  Unsteady flow  Rotor-stator interaction  Secondary vortex  Wake  Review

摘要:

为探究透平内部流场的非稳态特性及其演变特征，通过归纳国内外透平内部流动的试验研究，回顾了轴流透平、向心透平采用的试验方法及取得的研究进展，分析总结了试验方案与研究中存在的问题。目前，轴流式透平与平面叶栅的试验数量较多，试验的压力温度较低；向心式透平试验研究还比较少，并且试验多处于高温高压环境；随着接触式测量设备性能的大幅提升，其目前在透平非稳态试验中得到广泛应用，例如气动探针已经能够满足1×10⁶Hz的高频采集要求；上游尾迹以及叶顶泄漏涡扰动下轴流式透平叶表附面层的转捩机制，以及向心式透平盘腔泄漏流与主流流场的非定常掺混等问题还有待进一步研究。

Abstract:

To clarify the unsteadiness and evolution process of internal flow field in turbines, the experimental method and research progress of the axial turbine and radial turbine were reviewed based on domestic and foreign researches, and some disadvantages of present experimental scheme and research were also performed. The results show that experiments, whose pressure and temperature are usually low, in axial turbines and linear cascades have been widely investigated, while relatively less experiments, whose pressure and temperature are relatively high, in radial turbines can be seen in the existing literatures. The contact measurement has been widely used in unsteady experiments of turbines for its increasingly improved performance. For example, the pneumatic probes could meet the requirement of high sampling rate, which may be up to 1×10⁶Hz, very well. However, the transition mechanisms of surface boundary layer under the disturbance of upstream wake and tip leakage vortex in axial turbines are still not fully explained and need further researches, so does the unsteady mixing between the cavity leakage flow and the main flow in radial turbines.