Experimental Investigation on the Development Process of Large-Scale Low-Speed Stall Disturbance in Contra-Rotating Comp

  • PDF / 2,177,117 Bytes
  • 10 Pages / 595.22 x 842 pts (A4) Page_size
  • 42 Downloads / 170 Views

DOWNLOAD

REPORT


https://doi.org/10.1007/s11630-020-1341-z

Article ID: 1003-2169(2020)00-0000-00

Experimental Investigation on the Development Process of Large-Scale Low-Speed Stall Disturbance in Contra-Rotating Compressor YUE Shaoyuan, WANG Yan’gang*, WEI Liguo, WANG Hao* School of Power and Energy, Northwestern Polytechnical University, Xi’an 710072, China © Science Press, Institute of Engineering Thermophysics, CAS and Springer-Verlag GmbH Germany, part of Springer Nature 2020

Abstract: In order to better understand the stall process of a contra-rotating compressor, the detailed characteristic and multi-channel unsteady pressure signals have been achieved by a special layout of high-frequency response pressure sensors. The array consists of thirty-one high-frequency response dynamic sensors coupled with two optical fiber sensors that were installed on the compressor casing in the direction of circumferential and chordwise of the upstream and downstream of the contra-rotating rotors. A significant hysteresis loop during the stall-recovery process of the contra-rotating compressor was captured successfully. The time series of unsteady signals when the compressor was working on the point of stall occurrence, the period of fully stall, and recovery stall were studied and discussed. Results show a large scale, and low-speed disturbance occurred abruptly at the leading-edge plane of the rear rotor and expands until it passes through both rotors. The single stall cell occupied a circumferential range of 135° and moved in the direction of the rear rotor with an 8.3% shaft speed. As the mass flow rate dropped, the stall cell speed decreases. During the stall recovery process, the rotational speed of disturbance suddenly increased from 7.5% to 18% and even increased to 47% just before the moment when flow recovered axisymmetric. Compared with the rear rotor, the front one dropped out unstable conditions earlier.

Keywords: contra-rotating, abrupt, large scale, stall

1. Introduction “Stall” refers to the transient process from the near stall point (stable condition) to the “rotating stall” (relatively stable condition) [1] at which period the stall disturbance generates, propagates and grows until fully developed rotating stall. Rotating stall is a typical flow instability phenomenon in axial compressors and is one of the most severe aerodynamic disasters (the other is surge) in turbomachinery [2]. The typical rotating stall occurrence process [3] is: as the flow rate decreases, the compressor

Received: Sep 06, 2019 AE: DU Juan

supercharges capacity increases. When the flow rate decreases to a certain degree, the stall occurs, and the compressor performance drops sharply. When the flow rate increases to a certain extent, the compressor quickly recovers to a stable operating point, and the compressor has a significant hysteresis loop in the stall-recovery process. In 1941, Frank Whittle [4] discovered that when the flow rate was reduced to a certain extent, one of the blades in the centrifugal compressor first experienced flow instabil