Compressor is one of the three components of gas turbines. While constantly pursuing high pressure ratio and high efficiency, the internal flow stability problem is also a long-term research hotspot. To this end, in addition to the continuous research on blade design, multi-stage compressor matching and other technologies, the International Institute also conducts in-depth research on the internal mechanism of axial flow compressor instability and control methods in order to obtain a more reasonable and reliable expansion. Stable method. The Institute of Engineering Thermophysics, Chinese Academy of Sciences, has been engaged in research on the internal flow instability mechanism of compressors for many years, and explained the correlation between the unsteady nature of the leakage flow in the tip clearance and stall, and has received extensive attention internationally. Accredited. On this basis, a relevant mechanism study was carried out around the simple and effective method of steady-state expansion of the circumferential slot machine to achieve the following results:
First, in the study of the mechanism of the stabilization of the circumferential groove treatment, taking the weekly single groove as the entry point, the effect of the single-slot position on the stability of the compressor (SMI curve), the mechanism, and the circumferential slot position were studied. Design guidelines. Among them, combining the experimental results of a series of single-slot and multi-slot casings, a preliminary selection of circumferential slot positions was proposed. At the same time, studies on high-speed compressors have revealed that before and after the application of a circumferential single-slot, the occurrence of compressor stall precursors depends on the axial momentum balance between the tip leakage flow and the mainstream.
Second, in the optimization design of the circumferential groove processing: (1) Developed a control body analysis method for moving the end zone of the blade to determine the change of the axial momentum along the chord direction of the blade end zone control body, and proposed It can quickly determine the effect of circumferential groove processing and stabilization by controlling the body axial momentum bell curve; (2) Using the control body analysis method, different structures of circumferential grooves are processed in low speed and transonic compressor respectively. The study successfully predicted the effect of stabilization of each treatment structure and was verified by the corresponding experimental results. (3) The control body analysis method was extended to the entropy production analysis under the design conditions of the compressor and used to determine the different circumferential directions. Influence of Groove Structure on Compressor Peak Efficiency and End Zone Flow Loss
Third, in the experimental study of the circumferential groove treatment: (1) Developed a measurement method using multiple monofilament hot wire probes to realize the three-dimensional flow at the interface between the circumferential groove and the moving passage Measurements; (2) An experimental study was conducted on the open-face flow of a single groove in a typical position by means of this method, revealing the difference in the flow characteristics of the single-slot circumferential surface and its interaction with the flow in the channel. (3) In combination with numerical simulation studies, the differences in the flow structure of the rotor end zone at the single-slot opening surface with different expansion stability effects are explained, in particular, the flow structure changes caused by the single-slot treatment without stabilization effect. .
The above research was supported by the National Natural Science Foundation of China. The relevant research results have been published in the ASME Turbo Expo IGTI 2013-2015 and many papers have been submitted to the ASME Journal of Turbomachinery, AIAA Journal of Propulsion and Power, and other journals.
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