A novel approach to determine splitter vane length for an extremely high hub/tip ratio mixed-flow compressor impeller

Abstract

This paper presents an approach to determine splitter vane length in radial compressor impellers based on a modified 1D performance prediction model, which considers the effects of splitter vane length and blade number on impeller internal losses. The splitter vane length corresponding to optimum blade number is investigated to achieve the maximum efficiency of a mixed-flow compressor impeller with an extremely high hub/tip ratio. An empirical formula for calculating splitter vane length is proposed. CFD results show that blade number and splitter vane length have a complex coupling interaction which makes it inappropriate to be described by equivalent solidity or effective blade number. 1D results and CFD verification indicate that optimum full-length blade number is 42 and corresponding splitter vane length is 20% of full-length blade length at design flow rate. The impeller peak efficiency mainly depends on minimum loss superposition of blade loading, skin friction and tip clearance. With the increase of splitter vane length and blade number, blade loading loss and clearance loss decline while skin friction loss increases.

Keywords

Performance prediction model internal losses splitter vane blade number mixed-flow compressor

Get full access to this article

View all access options for this article.

References

Musgrave

Plehn

. Mixed-flow compressor stage design and test results with a pressure ratio of 3:1. J Turbomach 1987; 109: 513–519.

Groh

Wood

Kulp

, et al. Evaluation of a high hub/tip ratio centrifugal compressor. J Fluids Eng 1970; 92: 419–428.

Rodgers C and Brown D. High hub/tip ratio centrifugal compressors. ASME Turbo Expo 2009: Power for Land, Sea, and Air, 2009; 7: 1151–1161. doi:10.1115/GT2009-59012.

Galvas MR. Analytical correlation of centrifugal compressor design geometry for maximum efficiency with specific speed. NASA-TN-D-6729, 1972; 19720011352. https://ntrs.nasa.gov/search.jsp?R=19720011352.

Aungier

. Mean streamline aerodynamic performance analysis of centrifugal compressors. J Turbomach 1995; 117: 360–366.

Rodgers C. Effects of blade number on the efficiency of centrifugal compressor impellers. ASME Turbo Expo 2000: Power for Land, Sea, and Air, 2000; 1: V001T03A029. doi:10.1115/2000-GT-0455.

Pfleiderer

. Die Kreiselpumpen für Flüssigkeiten und Gase, Berlin: Springer-Verlag, 1961.

Eckert

. Axialkompressoren und Radialkompressoren, Berlin: Springer, 1953, pp. 89–275.

. Principles of centrifugal compressors, Beijing: China Machine Press, 1990.

10.

Reddy

Konnur

. Optimum number of blades for maximum efficiency of centrifugal blowers. Aircr Eng Aerosp Tec 1971; 43: 16–17.

11.

Djebedjian

. Theoretical model to predict the performance of centrifugal pump equipped with splitter blades. Mansoura Eng J 2009; 34: 50–70.

12.

Galvas MR. Fortran program for predicting off-design performance of centrifugal compressors. NASA-TN-D-7487, 1973; 19740001912. https://ntrs.nasa.gov/search.jsp?R=19740001912.

13.

Yoon

Chung

. An optimum set of loss models for performance prediction of centrifugal compressors. Proc IMechE, Part A: J Power and Energy 1997; 211: 331–338.

14.

Song

. A new optimization method for centrifugal compressors based on 1D calculations and analyses. Energies 2015; 8: 4317–4334.

15.

Wang

Lin

Nie

, et al. Design and performance evaluation of a very low flow coefficient centrifugal compressor. Int J Rotating Mach 2013, pp. 2013: 293486–2013: 293486.

16.

Xue

Zhitao

, et al. Research of off-design performance prediction model of centrifugal compressor with adjustable guide vane. Proc CSEE 2016; 36: 3381–3390.

17.

Yang

Zheng

Zhang

, et al. Improved performance prediction model for turbocharger compressor. SAE Int J Fuels Lubr 2009; 1: 1159–1166.

18.

Tian

Shan

. Loss model application study in the through-flow inverse design approach for centrifugal compressors. J Aerosp Pow 2009; 24: 858–866.

19.

Wennerstrom

. Some experiments with a supersonic axial compressor stage. J Turbomach 1987; 109: 388–397.

20.

Tzuoo KL, Hingorani SS and Sehra AK. Design methodology for splittered axial compressor rotors. ASME 1990 International Gas Turbine and Aeroengine Congress and Exposition, 1990; 5: V005T16A002. doi:10.1115/90-GT-066.

21.

Liu

. Development of a preliminary design method for subsonic splittered blades in highly loaded axial-flow compressors. Appl Sci 2017; 7: 283–283.

22.

Qiu

Japikse

Zhao

, et al. Analysis and validation of a unified slip factor model for impellers at design and off-design conditions. J Turbomach 2011; 133: 041018–041018.

23.

Eisenlohr G, Krain H, Richter FA, et al. Investigations of the flow through a high pressure ratio centrifugal impeller. ASME Turbo Expo 2002: Power for Land, Sea, and Air 2002; 5: 649–657. doi:10.1115/GT2002-30394.

Supplementary Material

Please find the following supplemental material available below.

For Open Access articles published under a Creative Commons License, all supplemental material carries the same license as the article it is associated with.

For non-Open Access articles published, all supplemental material carries a non-exclusive license, and permission requests for re-use of supplemental material or any part of supplemental material shall be sent directly to the copyright owner as specified in the copyright notice associated with the article.

0.00 MB

0.17 MB