The Three-Dimensional Flow and Blade Wake in an Axial Plane Downstream of an Axial Compressor Rotor

Author(s):  
P. Kool ◽  
J. DeRuyck ◽  
Ch. Hirsch

The three-dimensional flow field has been measured in an axial plane downstream of a low speed axial compressor rotor with a rotated single slanted hot wire. A method is described which allows one to calculate three mutually perpendicular velocity components from hot-wire data, and use is made of the technique of periodic sampling and averaging to extract the pitchwise fluctuating flow from the stationary hot-wire signals. These data contain useful information. The radial distribution of the pitchwise averaged flow variables is compared with classical pneumatic measurements and with the results of a quasi three-dimensional finite-element calculation and a three-dimensional end-wall boundary layer calculation. Finally, the wake characteristics are given and a simple correlation is presented which allows one to determine the wake velocity defect from a single wake shape factor.

1977 ◽  
Vol 99 (2) ◽  
pp. 168-179 ◽  
Author(s):  
Ch. Hirsch ◽  
P. Kool

Hot wire instrumentation and a periodic sampling and averaging technique have been used in order to measure the three-dimensional flow field behind a rotor of an axial compressor stage. A single slanted rotating wire allows the determination of the three components of the blade-to-blade velocity distribution together with informations on the turbulence level. A description is given of the measurement technique, and typical experimental results are presented.


1972 ◽  
Vol 23 (4) ◽  
pp. 285-300 ◽  
Author(s):  
C E Whitfield ◽  
J C Kelly ◽  
B Barry

SummaryMany investigators have studied the aerodynamics of axial flow turbomachinery but none has produced a complete map of the three-dimensional flow behind a rotor row. This is of considerable interest to the aero-acoustician. A system is described which uses a constant temperature hot-wire anemometer to analyse the flow behind such a rotor. Although much information may be extracted by using the technique, its interpretation depends to a large extent on its form of presentation. An analysis of the flow behind a research fan is used as a means of discussing various forms of visual presentation.


1988 ◽  
Vol 110 (2) ◽  
pp. 110-119 ◽  
Author(s):  
Y. T. Chew ◽  
R. L. Simpson

An explicit non-real time method of reducing triple sensor hot-wire anenometer data to obtain the three mean velocity components and six Reynolds stresses, as well as their turbulence spectra in three-dimensional flow is proposed. Equations which relate explicitly the mean velocity components and Reynolds stresses in laboratory coordinates to the mean and mean square sensors output voltages in three stages are derived. The method was verified satisfactorily by comparison with single sensor hot-wire anemometer measurements in a zero pressure gradient incompressible turbulent boundary layer flow. It is simple and requires much lesser computation time when compared to other implicit non-real time method.


1948 ◽  
Vol 159 (1) ◽  
pp. 255-268 ◽  
Author(s):  
A. D. S. Carter

It has long been known that the energy losses occurring in an axial compressor or turbine cannot be fully accounted for by the skin-friction losses on the blades and annulus walls. The difference, usually termed secondary loss, is attributed to miscellaneous secondary flows which take place in the blade row. These flows both cause losses in themselves and modify the operating conditions of the individual blade sections, to the detriment of the overall performance. This lecture analyses the three-dimensional flow in axial compressors and turbines, so that, by appreciation of the factors involved, possible methods of improving the performance can readily be investigated. The origin of secondary flow is first examined for the simple case of a straight cascade. The physical nature of the flow, and theories which enable quantitative estimates to be made, are discussed at some length. Following this, the three-dimensional flow in an annulus with a stationary blade row is examined, and, among other things, the influence of radial equilibrium on the flow pattern is noted. All physical restrictions are then removed, and the major factors governing the three-dimensional flow in an actual machine are investigated as far as is possible with existing information, particular attention being paid to the influence of a non-uniform velocity profile, tip clearance, shrouding, and boundary layer displacement. Finally the various empirical factors used in design are discussed, and the relationships between them established.


1977 ◽  
Vol 99 (3) ◽  
pp. 460-475 ◽  
Author(s):  
A. H. Epstein

The flow in a 59-cm dia high work, transonic compressor rotor has been visualized using a fluorescent gas, 2,3, butanedione, as a tracer. The technique allows the three-dimensional flow to be imaged as a set of distinct planes. Quantitative static density maps were obtained by correcting the images for distortion and nonlinearities introduced by the illumination and imaging systems. These images and maps were used to analyze the three-dimensional nature of the blade’s boundary layer and shock system.


1963 ◽  
Vol 14 (2) ◽  
pp. 125-142 ◽  
Author(s):  
W. T. Howell

SummaryThe subject of three-dimensional flow in axial compressors and turbomachines has been extensively studied since 1945. This paper gives a means of calculating the approximate three-dimensional flow in an axial compressor by giving expressions for the slope of the velocity profile as a function of the axial co-ordinate. These expressions bring out the rôle of the ratio of stage inlet annulus height to stage length in the three-dimensional flow in these machines. The effect of the three-dimensional flow on the stage temperature rise at mean radius is discussed by introducing a work done factor.


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