Typically several hundred million data points arise from a comprehensive measurement campaign carried out in a centrifugal compressor test rig with the fast-response aerodynamic probe system (see Part 1). In order to obtain a maximum of information about the unsteady flow at any position in this turbomachine, the time-resolved data processing method has to be optimized. In contrast to the standard time-averaged flow measurements with pneumatic probes, the objective of fast-response aerodynamic probe measurements and of data processing is to extract novel information about crucial unsteady phenomena like turbulence, row-to-row interaction, modal or rotating stall, leakage flow effects, etc. In such cases, the simultaneous measurement of static and total pressures and flow vectors is of particular interest. Novel information means the analysis of averaged and time-resolved (wavelet) spectra, autocorrelations or time averages properly conserving physical fluxes, etc. Different averaging methods are applied to compress the time-dependent data measured by a one-sensor-probe (see Part 2) in a centrifugal compressor. Such results could be used for comparison with pneumatic sensor measurements and CFD calculations. The comparison of averaging methods includes the averaging theories by Traupel and by Dzung, which are compared to simple arithmetic time averaging. From there the specific stage work is calculated. In analyzing the time dependency, several ensemble-averaging procedures for flow pressure and velocity are utilized for separating deterministic from stochastic fluctuations, extracting blade row finger prints or investigating low-frequency surge type fluctuations. With respect to the selection and overall optimization of data processing methods, an overview of generic tools is given and the modularity of the processing procedures is discussed. [S0889-504X(00)01203-4]

Issue Section:
Technical Papers
Keywords:
gas turbines, measurement systems, compressors, aerodynamics, probes, centrifuges, flow control, pressure sensors, velocity measurement, fluctuations, frequency control
Topics:
Compressors, Flow (Dynamics), Pressure, Probes, Fluctuations (Physics), Blades
1.
Traupel, W., 1988, Thermische Turbomaschinen I, Springer-Verlag, Berlin, p. 307.
2.
Dean
, Jr.,
R. C.
, and
Senoo
,
Y.
,
1960
, “
Rotating Wakes in Vaneless Diffusers
,”
ASME J. Basic Eng.
,
82
, No. 3.
3.
Eckardt
,
D.
,
1975
, “
Instantaneous Measurements in the Jet-Wake Discharge Flow of a Centrifugal Compressor Impeller
,”
ASME J. Eng. Power
,
97
, No. 3.
4.
Adamczyk
,
J. J.
,
Mulac
,
R. A.
, and
Celestina
,
M. L.
,
1986
, “
A Model for Closing the Inviscid Form of the Average-Passage Equation System
,”
ASME J. Turbomach.
,
108
, pp.
180
–
186
.
5.
Gerhard
,
P. M.
,
1981
, “
Averaging Methods for Determining the Performance of Large Fans From Field Measurements
,”
ASME J. Eng. Power
,
103
, No. 2.
6.
Kreitmeier, F., and Juvet, P. J., 1997, “Demonstration of a Balance-Based Procedure for Time-Averaging and Modeling of Compressible Three-Dimensional Unsteady Turbulent Flows.”
7.
Ng
,
W. F.
, and
Epstein
,
A. H.
,
1985
, “
Unsteady Losses in Transonic Compressors
,”
ASME J. Eng. Gas Turbines Power
,
107
, pp.
345
–
353
.
8.
Ruck, G., 1989, “Verfahren zur instationa¨ren Geschwindigkeits-und Turbulenzmessung mit einer pneumatisch messenden Keilsonde,” Mitteilungen des Institutes No. 33, Institut fu¨r Thermische Stro¨mungsmaschinen und Maschinenlaboratorium der Universita¨t Stuttgart, Stuttgart, Germany.
9.
Roduner
,
C.
,
Kupferschmied
,
P.
,
Ko¨ppel
,
P.
, and
Gyarmathy
,
G.
,
2000
, “
On the Development and Application of the Fast-Response Aerodynamic Probe System for Turbomachines—Part 2: Flow, Surge, and Stall in a Centrifugal Compressor
,”
ASME J. Turbomach.
,
122
, pp.
517
–
526
.
10.
Dzung, L. S., 1967, “Mittelungsverfahren in der Theorie der Schaufelgitter,” Brown Boveri Mitteilungen.
11.
Dzung, L. S., 1970, “Flow Research on Blading,” Proc. Symposium of Flow Research on Blading.
12.
Roduner, C., Ko¨ppel, P., Kupferschmied, P., and Gyarmathy, G., 1998, “Comparison of Measurement Data at the Impeller Exit of a Centrifugal Compressor Measured with both Pneumatic and Fast-Response Probes,” ASME Turbo Expo’ 98, 98-GT-241, Stockholm.
13.
Hunziker, R., 1993, “Einfluss der Diffusorgeometrie auf die Instabilita¨tsgrenze des Radialverdichters,” PhD thesis No. 10252, ETH Zu¨rich, Switzerland.
14.
Kupferschmied
,
P.
,
Ko¨ppel
,
P.
,
Roduner
,
C.
, and
Gyarmathy
,
G.
,
2000
, “
On the Development and Application of the Fast-Response Aerodynamic Probe System for Turbomachines—Part 1: The Measurement System
,”
ASME J. Turbomach.
,
122
, pp.
505
–
516
.
15.
Gossweiler, C., Humm, H. J., and Kupferschmied, P., 1992, “Development of a System for Aerodynamic Fast-Response Probe Measurements,” Proc. of the 18th Congress of Int. Council of the Aeronautic Sciences (ICAS), Beijing.
16.
Gossweiler
,
C.
,
Kupferschmied
,
P.
, and
Gyarmathy
,
G.
,
1995
, “
On Fast-Response Probes: Part I—Technology, Calibration and Application to Turbomachinery
,”
ASME J. Turbomach.
,
117
, pp.
611
–
617
.
17.
Kupferschmied, P., Gossweiler, C., and Gyarmathy, G., 1994, “Aerodynamic Fast-Response Probe Measurement Systems: State of Development, Limitation and Future Trends,” Proc. 12th Symposium on Measuring Techniques for Transonic and Supersonic Flows in Cascades and Turbomachines, Prague, Czech Republic.
18.
Kupferschmied, P., 1998, “Zur Methodik zeitaufgelo¨ster Stro¨mungssondenmessungen in Verdichtern and Turbinen,” PhD thesis No. 12774, ETH Zu¨rich, Switzerland.
19.
Stahlecker, D., and Gyarmathy, G., 1998, “Investigations of Turbulent Flow in a Centrifugal Compressor Vaned Diffuser by Three-Component Laser Velocimetry,” ASME Paper No. 98-GT-300.
20.
Casartelli
,
E.
,
Saxer
,
A. P.
, and
Gyarmathy
,
G.
,
1999
, “
Numerical Flow Analysis in a Subsonic Vaned Radial Diffuser With Leading Edge Redesign
,”
ASME J. Turbomach.
,
121
, pp.
119
–
125
.
21.
Herter, D., Chrisander, O., and Gossweiler, C., 1992, “AW-System—An Interactive Environment for the Evaluation of Large Time Series,” Proc. 11th Symposium on Measuring Techniques for Transonic Flows in Cascades and Turbomachines, Munich, Germany.
22.
Gizzi, W., Roduner, C., Stahlecker, D., Ko¨ppel, P., and Gyarmathy, G., 1999, “Time Resolved Measurements With Fast-Response Probes and Laser-Doppler-Velocimetry at the Impeller Exit of a Centrifugal Compressor—A Comparison of Two Measurement Techniques,” Proc. 3rd European Conference on Turbomachinery.
23.
Humm
,
H. J.
,
Gossweiler
,
C.
, and
Gyarmathy
,
G.
,
1995
, “
On Fast-Response Probes, Part 2: Aerodynamic Design Studies
,”
ASME J. Turbomach.
,
117
, pp.
618
–
624
.
Copyright © 2000
 by ASME
You do not currently have access to this content.