Research Papers

The Impact of Inlet Distortion and Reduced Frequency on the Performance of Centrifugal Compressors

[+] Author and Article Information
A. Grimaldi

Baker Hughes, a GE company (BHGE),
Florence 50127, Italy
e-mail: angelo.grimaldi@bhge.com

V. Michelassi

Baker Hughes, a GE company (BHGE),
Florence 50127, Italy
e-mail: vittorio.michelassi@bhge.com

Manuscript received June 29, 2018; final manuscript received July 9, 2018; published online October 1, 2018. Editor: Jerzy T. Sawicki.

J. Eng. Gas Turbines Power 141(2), 021012 (Oct 01, 2018) (9 pages) Paper No: GTP-18-1401; doi: 10.1115/1.4040907 History: Received June 29, 2018; Revised July 09, 2018

This paper discusses the impact of inlet flow distortions on centrifugal compressors based upon a large experimental data base in which the performance of several impellers in a range of corrected flows and corrected speeds have been measured after been coupled with different inlet plenums technologies. The analysis extends to centrifugal compressor inlets including a side stream, typical of liquefied natural gas applications. The detailed measurements allow a thorough characterization of the flow field and associated performance. The results suggest that distortions can alter the head by as much as 3% and efficiency of around 1%. A theoretical analysis allowed to identify the design features that are responsible for this deviation. In particular, an extension of the so-called “reduced-frequency,” a coefficient routinely used in axial compressors and turbine aerodynamics to weigh the unsteadiness generated by upstream to downstream blade rows, allowed to determine a plenum-to-impeller reduced frequency that correlates very well with the measured performance. The theory behind the new coefficient is discussed together with the measurement details and validates the correlation that can be used in the design phase to determine the best compromise between the inlet plenum complexity and impact on the first stage.

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Ariga, I. , Kasai, N. , masuda, S. , Watanabe, Y. , and Watanabe, I. , 1983, “ The Effect of Inlet Distortion on the Performance Characteristics of a Centrifugal Compressor,” ASME J. Eng. Power, 105(2), pp. 223–230. [CrossRef]
Stenning, A. H. , 1980, “ Inlet Distortion Effects in Axial Compressors,” ASME J. Fluids Eng., 102(1), pp. 7–13. [CrossRef]
Longley, J. P. , and Greitzer, E. M. , 1992, “ Inlet Distortion Effects in Aircraft Propulsion System Integration,” National Aeronautics and Space Administration, Washington, DC, Report No. AGARD-LS-183. https://ntrs.nasa.gov/search.jsp?R=19920019221
Greitzer, E. M. , Epstein, A. H. , Guenette, G. R. , Gysling, D. L. , Haynes, J. , Hendricks, G. J. , Paduano, J. , Simon, J. S. , and Valavani, L. , 1992, “ Dynamic Control of Aerodynamic Instabilities in Gas Turbine Engines,” National Aeronautics and Space Administration, Washington, DC, Report No. AGARD-LS-183. https://ntrs.nasa.gov/search.jsp?R=19920019223
Shen, F. , Yu, L. , Cousins, W. T. , Sishtla, V. , and Sharma, O. P. , 2016, “ Numerical Investigation of the Flow Distortion Impact on a Refrigeration Centrifugal Compressor,” ASME Paper No. GT2016-57063.
Michelassi, V. , and Giachi, M. , 1997, “ Experimental and Numerical Analysis of Compressor Inlet Volutes,” ASME Paper No. 97-GT-481.
Kim, Y. , Engeda, A. , Aungier, R. , and Direnzi, G. , 2001, “ The Influence of Inlet Flow Distortion on the Performance of a Centrifugal Compressor and the Development of an Improved Inlet Using Numerical Simulations,” Proc. Inst. Mech. Eng., Part A, 215(3), pp. 323–338.
Xin, J. , Wang, X. , Zhou, L. , Ye, Z. , and Liu, H. , 2016, “ Numerical Investigation of the Flow Field and Aerodynamic Load on Impellers in Centrifugal Compressors With Different Radial Inlets,” ASME Paper No. GT2016–57180.
Medic, G. , Sharma, O. P. , Jongwook, J. , Hardin, L. W. , McCormick, D. C. , Cousins, W. T. , Laurie, E. A. , Shabbir, A. , Holley, B. M. , and Van Slooten, P. R. , 2017, “ High Efficiency Centrifugal Compressor for Rotorcraft Applications,” NASA Glenn Research Center, Cleveland, OH, Report No. NASA/CR-2014-218114. https://ntrs.nasa.gov/search.jsp?R=20180001472
Pazzi, S. , and Michelassi, V. , 2000, “ Analysis and Design Outlines of Centrifugal Compressor Inlet Volutes,” ASME Paper No. 2000-GT-0464.
Toni, L. , Ballarini, V. , Cioncolini, S. , Persico, G. , and Gaetani, P. , 2010, “ Unsteady Flow Field Measurements in an Industrial Centrifugal Compressor,” 39th Turbomachinery Symposium, Houston, TX, Oct. 4–7, pp. 49–58. https://pdfs.semanticscholar.org/1f92/34c5ea0c36861a9365632e546eff95ee0559.pdf
Satish, V. V. N. K. , Guidotti, E. , Rubino, D. T. , Tapinassi, L. , and Prasad, S. , 2013, “ Accuracy of Centrifugal Compressor Stages Performance Prediction by Means of High Fidelity CFD and Validation Using Advanced Aerodynamic Probe,” ASME Paper No. GT2013-95618.
Tapinassi, L. , Fiaschi, D. , and Manfrida, G. , 2006, “ Improving the Accuracy of Tests for Centrifugal Compressors Stages Performance Prediction,” ASME Paper No. ESDA2006-95070.
Ferrara, G. , Ferrari, L. , and Baldassarre, R. , 2006, “ Experimental Characterization of Vaneless Diffuser Rotating Stall—Part V: Influence of Diffuser Geometry on Stall Inception and Performance (3rd Impeller Tested),” ASME Paper No. GT2006-90693.
Michelassi, V. , Chen, L. , Pichler, R. , Sandberg, R. , and Bhaskarna, R. , 2016, “ High-Fidelity Simulations of Low-Pressure Turbines: Effect of Flow Coefficient and Reduced Frequency on Losses,” ASME J. Turbomach., 138(11), p. 111006. [CrossRef]
Leggett, J. , Priebe, S. , Shabbir, A. , Sandberg, R. , Richardson, E. , and Michelassi, V. , 2017, “ LES Loss Prediction in an Axial Compressor Cascade at Off-Design Incidences With Free Stream Disturbances,” ASME Paper No. GT2017-64292.
Cumpsty, N. A. , 1989, “ Compressor Aerodynamics,” Longman, Harlow, UK.
Gong, X. , and Chen, R. , 2014, “ Total Pressure Loss Mechanism of Centrifugal Compressors,” J. Mech. Eng. Res., 4(2), pp. 45–59. [CrossRef]


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Fig. 4

Typical deviations of polytrophic efficiency (left), and work coefficient (right), solid line = intermediate stage, dashed line = first stage

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Fig. 3

Impeller inlet vector diagram; C+ is the absolute velocity in the left half of the plenum, C refers to the right half

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Fig. 2

Flow distortions in terms of inlet absolute flow angle associated with different plenum types

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Fig. 1

First stage configuration (a), intermediate stage configuration (b), intermediate stage with side stream configuration (c)

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Fig. 6

Sketch of the impeller parameters

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Fig. 10

Incidence at impeller tip

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Fig. 11

Computed versus measured work coefficient as a function of the inlet contribution only

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Fig. 7

Deviation from expected work coefficient as a function of reduced frequency, Fred. Different symbols refer to different configurations listed in Table 3.

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Fig. 8

Yaw angle (above) and relative angle (below) as seen by the impeller at the plenum exit section, 90% span along the circumference: (a) no IGV, (b) straight IGV, and (c) cambered IGV. (y-axis scale in common for the three plots).

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Fig. 9

FFT of the yaw angle at the plenum exit along the circumference at 90% span: (a) no IGV, (b) straight IGV, and (c) cambered IGV

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Fig. 12

Meridional section in the proximity to the impeller leading edge. Solid line = first stage with inlet plenum, dot-dash line = intermediate stage.

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Fig. 13

Relative Mach number at blade tip. Solid line = low curvature inlet with 16 IGV, dashed line = intermediate stage with high curvature.

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Fig. 16

Expected impact on stage performance

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Fig. 14

Relative Mach number and Incidence at blade tip. Same meridional curvature and different number of upstream vanes.

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Fig. 15

Deviation from expected polytrophic efficiency as a function of reduced frequency, Fred



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