scholarly journals Discussion: “A New Appraisal of Reynolds Number Effects on Centrifugal Compressor Performance” (Wiesner, F. J., 1979, ASME J. Eng. Power, 101, pp. 384–392)

1979 ◽  
Vol 101 (3) ◽  
pp. 392-393 ◽  
Author(s):  
H. Davis
1979 ◽  
Vol 101 (3) ◽  
pp. 384-392 ◽  
Author(s):  
F. J. Wiesner

This paper summarizes the results of an investigation into the effects of Reynolds number on the performance of centrifugal compressor stages, using a computer program for the detailed prediction of component and overall performance characteristics. This investigation included wide variation of stage geometries, speeds, and fluid conditions, resulting in diffuser inlet absolute Reynolds number variations over the range from 5 × 102 to 5 × 108. The computer results indicate that variations in Reynolds number and in relative roughness will produce variations in all significant performance parameters: the flow coefficient, the work coefficient, and the efficiency. Correlations of these results with various sources of test data on single and multistage centrifugal compressors produce very satisfactory comparisons. As a result of this study, improved empirical methods are recommended for making practical adjustments of compressor performance with variation in Reynolds number. These recommendations should be taken into account in the modernization of all centrifugal compressor performance test codes such as those formulated by ASME and ISO.


1979 ◽  
Vol 101 (3) ◽  
pp. 337-342 ◽  
Author(s):  
T. Mashimo ◽  
I. Watanabe ◽  
I. Ariga

Fluid loss caused by leaks through the impeller tip clearance was investigated for a centrifugal compressor. Operating conditions, Reynolds number, and clearance were varied independently during the experiment. It was found that the average compressor performance would be reduced by about 4 percent when the relative clearance was increased from 0.0125 to 0.125 and the resulting leakage loss was dependent on the Reynolds number, the tendency of which was just opposite in case of wall friction loss, as was well-known. Moreover, a determination of the leakage loss coefficient was made as a function of the relative clearance, relative leak level and the Reynolds number as the result of this experiment.


1968 ◽  
Vol 90 (2) ◽  
pp. 149-156 ◽  
Author(s):  
A. B. Wassell

The influence of variations in flow Reynolds number on the performance of axial compressors has been studied (changes in Reynolds number being, for the most part, achieved by changes in the inlet total pressure at or near the design speed). The measured results, so achieved, have been correlated to show how the main compressor performance parameters vary with Reynolds number. Reference has been made to cascade data to assist in choosing the form of the correlation, which is essentially empirical. A good correlation of the measured performance changes on component tests has been obtained. The method described, therefore, appears to be satisfactory for predicting trends for project assessments and avoids considering the detailed flow changes that occur within the machine as the Reynolds number is varied.


1984 ◽  
Vol 106 (2) ◽  
pp. 489-498 ◽  
Author(s):  
H. Simon ◽  
A. Bu¨lska¨mper

This paper summarizes the results of systematic investigations into the Reynolds number effects. It is based on performance map measurements carried out on a compressor test rig which was constructed primarily for this purpose. The measurements were performed for stages with different flow coefficients (0.004 ≦ φ1 ≦ 0.05), with different gases (air, nitrogen, helium, freon) and in the inlet pressure range 0.2 bar ≦ p1 ≦ 40 bar. By analogy with the turbulent flow in technically rough pipes, semi-empirical correlations are derived concerning the effects of the Reynolds number and the relative surface roughness on the characteristic performance parameters (efficiency, flow coefficient, head coefficient, work coefficient). For the detailed design calculation of individual stages, provision is made for the different effects on the hydraulic flow losses and the disk friction losses. Simplified correlations are given for the conversion of characteristics measured during thermodynamic performance tests. The correlations are applied to various single and multistage compressors, and the results compared with measured performance characteristics in the Reynolds number range 6 × 103 ≦ Ret ≦ 1.1 × 107. The good correspondence obtained forms the basis for recommending the application of these simplified relationships for the improvement of centrifugal compressor performance test codes (e.g. ASME PTC-10 and ISO TC 118).


1973 ◽  
Vol 95 (3) ◽  
pp. 251-256 ◽  
Author(s):  
R. C. Pampreen

This paper discusses aerodynamic considerations in the design of small turbomachinery axial and centrifugal compressors and fans. Test results are presented to show the effect of scaling on compressor performance. Correlations are presented which relate compressor efficiency to Reynolds Number and clearance. It is shown that clearance effects are more prominent when scaling designs, and Reynolds Number effects are more prominent as density is lowered.


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