Numerical investigation into the mechanism regarding the inception and evolution of flow unsteadiness induced by the tip leakage flow in a transonic compressor

Abstract

Unsteady flow in the blade tip region of modern axial flow compressors is one of the sources of loss, noise, and blade vibration. In some cases, it is potentially linked to stall inception. In this paper, the complex flow fields in the blade tip region of a transonic axial flow compressor rotor have been numerically investigated. The predicted results were validated by experimental data. Analyses of monitoring results of numerical probes showed that three typical flow characteristics occurred as the operating condition approached the stability limit: no flow fluctuation at the first operating point; flow fluctuation with high frequency and low amplitude at the second operating point; flow fluctuation with low frequency and high amplitude at the third operating point. Further analysis of the tip flow field showed that the evolution of the tip leakage vortex experienced three stages as the rotor was throttled. At the first stage, the TLV did not breakdown. At the second stage, a bubble-type breakdown of the tip leakage vortex occurred. At the third stage, a spiral-type breakdown of tip leakage vortex occurred. The current study demonstrated that the flow unsteadiness that appears within the test rotor was induced by the tip leakage vortex breakdown. Furthermore, with the transformation of the vortex breakdown form, the characteristic frequency and amplitude of the flow oscillation substantially changed.

Keywords

Flow unsteadiness tip leakage vortex vortex breakdown transonic compressor rotor

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References

Denton

. Loss mechanisms in turbomachines. J Turbomach 2008; 115: 621.

Adamczyk

Celestina

Greitzer

. The role of tip clearance in high-speed fan stall. J Turbomach 1993; 115: 28.

Zhang

, et al. Effects of the second-stage of rotor with single abnormal blade angle on rotating stall of a two-stage variable pitch axial fan. Energies 2018; 11: 3293.

Inoue

Kuroumaru

Fukuhara

. Behavior of tip leakage flow behind an axial compressor rotor. J Eng Gas Turbines Power 1986; 108: 7.

Kameier

Neise

. Experimental study of tip clearance losses and noise in axial turbomachines and their reduction. J Turbomach 1997; 119: 460.

Holzinger

Wartzek

Jüngst

, et al. Self-excited blade vibration experimentally investigated in transonic compressors: rotating instabilities and flutter. J Turbomach 2016; 138: 041006.

Schlechtriem S and Lötzerich M. Breakdown of tip leakage vortices in compressors at flow conditions close to stall. In: Volume 1: Aircraft engine; marine; turbomachinery; microturbines and small turbomachinery. New York: ASME, 1997, p. V001T03A004.

Furukawa

Inoue

Saiki

, et al. The role of tip leakage vortex breakdown in compressor rotor aerodynamics. J Turbomach 1999; 121: 469.

Furukawa M, Saiki K, Yamada K, et al. Unsteady flow behavior due to breakdown of tip leakage vortex in an axial compressor rotor at near-stall condition. In: Volume 1: Aircraft engine; marine; turbomachinery; microturbines and small turbomachinery. New York: ASME, 2000, p. V001T03A112.

10.

Yamada K, Furukawa M, Nakano T, et al.Unsteady three-dimensional flow phenomena due to breakdown of tip leakage vortex in a transonic axial compressor rotor. In: Volume 5: Turbo expo 2004, Parts A–B. New York: ASME, 2004, pp.515–526.

11.

Yamada K, Funazaki K and Sasaki H. Numerical investigation of relation between unsteady behavior of tip leakage vortex and rotating disturbance in a transonic axial compressor rotor. In: Volume 6: Turbomachinery, Parts A, B, C. New York: ASME, 2008, pp.425–436.

12.

Hah C, Rabe DC and Wadia AR. Role of tip-leakage vortices and passage shock in stall inception in a swept transonic compressor rotor. In: Volume 5: Turbo expo 2004, Parts A–B. New York: ASME, 2004, pp.545–555.

13.

Bergner J, Kinzel M, Schiffer H-P, et al. Short length-scale rotating stall inception in a transonic axial compressor: experimental investigation. In: Volume 6: Turbomachinery, Parts A–B. New York: ASME, 2006, pp.131–140.

14.

Zhang

Deng

Chen

, et al. Unsteady tip clearance flow in an isolated axial compressor rotor. J Therm Sci 2005; 14: 211–219.

15.

Zhang H, Deng X, Lin F, et al. A study on the mechanism of tip leakage flow unsteadiness in an isolated compressor rotor. In: Volume 6: Turbomachinery, Parts A–B. New York: ASME, 2006, pp.435–445.

16.

Tong Z, Lin F, Chen J, et al. The self-induced unsteadiness of tip leakage vortex and its effect on compressor stall inception. In: Volume 6: Turbo expo 2007, Parts A–B. New York: ASME, 2007, pp.1551–1562.

17.

Du J, Lin F, Zhang H, et al. Numerical investigation on the originating mechanism of unsteadiness in tip leakage flow for a transonic fan rotor. In: Volume 6: Turbomachinery, Parts A, B, C. New York: ASME, 2008, pp.707–717.

18.

Chu

, et al. Numerical investigation of the unsteady behaviour of tip clearance flow and its possible link to stall inception. Proc IMechE, Part A: J Power Energy 2010; 224: 85–96.

19.

Tian

, et al. Investigation of pre-stall behavior in an axial compressor rotor—part I: unsteadiness of tip clearance flow. J Turbomach 2012; 134: 051027.

20.

Reid L and Moore RD. Design and overall performance of four highly-loaded, high speed inlet stages for an advanced, high pressure ratio core compressor. NASA TP-1337, 1978.

21.

Van Zante

Strazisar

Wood

, et al. Recommendations for achieving accurate numerical simulation of tip clearance flows in transonic compressor rotors. J Turbomach 2000; 122: 733.

22.

. Numerical investigation into the unsteady flow and its associated flow mechanism in a transonic compressor rotor at near stall conditions. J Propul Technol 2016, pp. 37.

23.

Jameson A. Time dependent calculations using multigrid, with applications to unsteady flows past airfoils and wings. In: 10th computational fluid dynamics conference. Reston, VA: American Institute of Aeronautics and Astronautics, 1991.

24.

Sujudi D and Haimes R. Identification of swirling flow in 3-D vector fields. In: 12th computational fluid dynamics conference. Reston, VA: American Institute of Aeronautics and Astronautics, 1995.

25.

Sarpkaya

. On stationary and travelling vortex breakdowns. J Fluid Mech 1971; 45: 545–559.

26.

Leibovich

. The structure of vortex breakdown. Annu Rev Fluid Mech 1978; 10: 221–246.

27.

Delery

. Aspects of vortex breakdown. Prog Aerosp Sci 1994; 30: 1–59.

28.

Brücker

. Study of vortex breakdown by particle tracking velocimetry (PTV). Exp Fluids 1993; 14: 133–139.