Stall Warning by Blade Pressure Signature Analysis
Tóm tắt
At low mass flow rates, axial compressors suffer from flow instabilities leading to stall and surge. The inception process of these instabilities has been widely researched in the past---primarily with the aim of predicting or averting stall onset. In recent times, attention has shifted to conditions well before stall and has focused on the level of irregularity in the blade passing signature in the rotor tip region. In general, the irregularity increases in intensity as the flow rate through the compressor is reduced. Attempts have been made to develop stall warning/avoidance procedures based on the level of flow irregularity, but little effort has been made to characterize the irregularity itself, or to understand its underlying cause. Work on this project has revealed for the first time that the increase in irregularity in the blade passing signature is highly dependent on both tip-clearance size and eccentricity. In a compressor with small, uniform, tip-clearance, the increase in blade passing irregularity that accompanies a reduction in flow rate will be modest. If the tip-clearance is enlarged, however, there will be a sharp rise in irregularity at all circumferential locations. In a compressor with eccentric tip-clearance, the increase in irregularity will only occur in the part of the annulus where the tip-clearance is largest, regardless of the average clearance level. In this paper, some attention is also given to the question of whether the irregularity observed in the prestall flow field is due to random turbulence or to some form of coherent flow structure. Detailed flow measurements reveal that the latter is the case. From these findings, it is clear that a stall warning system based on blade passing signature irregularity would be difficult to implement in an aero-engine where tip-clearance size and eccentricity change during each flight cycle and over the life of the compressor.
Từ khóa
Tài liệu tham khảo
1986, A Theory of Post-Stall Transients in Axial Compression Systems. I. Development of Equations, ASME J. Eng. Gas Turbines Power, 108, 68, 10.1115/1.3239887
1986, A Theory of Post-Stall Transients in Axial Compression Systems. II. Application, ASME J. Eng. Gas Turbines Power, 108, 231, 10.1115/1.3239893
1998, A Study of Spike and Modal Stall Inception in a Low-Speed Axial Compressor, ASME J. Turbomach., 120, 393
Strazisar, A. J., Bright, M. M., Thorp, S., Culley, D. E., and Suder, K. L., 2004, “Compressor Stall Control Through Endwall Recirculation,” Proceedings of ASME Turbo Expo 2004, Vienna, Austria, June14–17, ASME Paper No. GT2004-54295. 10.1115/GT2004-54295
März, J., Hah, C., and Neise, W., 2001, “An Experimental and Numerical Investigation into the Mechanisms of Rotating Instability,” Proceedings of ASME Turbo Expo 2001, New Orleans, LA, June4–7, Paper No. 2001-GT-0536.
Dhingra, M., Neumeier, Y., Prasad, J. V. R., and Shin, H.-W., 2003, “Stall and Surge Precursors in Axial Compressors,” 39th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit, Hunstville, AL, July20–23, Paper No. AIAA 2003-4425.
Liu, Y., Dhingra, M., and Prasad, J. V. R., 2009, “Active Compressor Stability Management via a Stall Margin Control Mode,” Proceedings of ASME Turbo Expo 2009, Orlando, FL, June 8–12, ASME Paper No. GT2009-60140.10.1115/GT2009-60140
Christensen, D., Cantin, P., Gutz, D., Szucs, P. N., Wadia, A. R., Armor, J., Dhingra, M., Neumeier, Y., and Prasad, J. V. R., 2008, “Development and Demonstration of a Stability Management System for Gas Turbine Engines,” ASME J. Turbomach., 130, pp. 1–8. 10.1115/1.2777176
Gannon, A. J., Hobson, G. V., and Davis, W. L., 2010, “Axial Transonic Rotor and Stage Behaviour Near the Stability Limit,” Proceedings of ASME Turbo Expo 2010, Glasgow, UK, June14–18, ASME Paper No. GT2010-23713. 10.1115/GT2010-23713
1998, Effects of Non-Axisymmetric Tip Clearance on Axial Compressor Performance and Stability, ASME J. Turbomach., 120, 648, 10.1115/1.2841774
Bennington, M. A., Ross, M. H., Cameron, J. D., Morris, S. C., Du, J., Lin, F., and Chen, J., 2010, “An Experimental and Computational Investigation of Tip Clearance Flow and its Impact on Stall Inception,” Proceedings of ASME Turbo Expo 2010, Glasgow, UK, June14–18, ASME Paper No. GT2010-23516. 10.1115/GT2010-23516
Simpson, A. K., and Longley, J. P., 2007, “An Experimental Study of the Inception of Rotating Stall in a Single-Stage Low-Speed Axial Compressor,” Proceedings of ASME Turbo Expo 2007, May 14–17, ASMEPaper No. GT2007-27181.10.1115/GT2007-27181
1987, A Method for Assessing Effects of Circumferential Flow Distortion on Compressor Stability, ASME J. Turbomach., 109, 371, 10.1115/1.3262116
2001, Rotating Instabilities in an Axial Compressor Originating From the Fluctuating Blade Tip Vortex, ASME J. Turbomach., 123, 453, 10.1115/1.1370160
Wisler, D. C., Beacher, B. F., and Shin, H-W., 2002, “Effects of Loading and Clearance Variation on Tip Vortex and Endwall Blockage,” Proceedings of the 9th International Symposium on Transport Phenomena and Dynamics of Rotating Machinery, Honolulu, HI, February10–14.