Research Papers: Gas Turbines: Controls, Diagnostics, and Instrumentation

One-Dimensional Flow-Adaptive Measurement Grid Algorithm for Pneumatic Probe Measurements

[+] Author and Article Information
Christian Bartsch

Institute of Jet Propulsion and Turbomachinery,
RWTH Aachen University,
Templergraben 55,
Aachen 52062, Germany
e-mail: bartsch@ist.rwth-aachen.de

Magnus Hölle

Institute of Jet Propulsion and Turbomachinery,
RWTH Aachen University,
Templergraben 55,
Aachen 52062, Germany
e-mail: hoelle@ist.rwth-aachen.de

Peter Jeschke

Institute of Jet Propulsion and Turbomachinery,
RWTH Aachen University,
Templergraben 55,
Aachen 52062, Germany
e-mail: jeschke@ist.rwth-aachen.de

Timo Metzler

MTU Aero Engines AG,
Dachauer Straße 665,
Munich 80995, Germany
e-mail: timo.metzler@mtu.de

1Corresponding author.

Contributed by the Controls, Diagnostics and Instrumentation Committee of ASME for publication in the JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER. Manuscript received July 14, 2015; final manuscript received August 4, 2015; published online September 22, 2015. Editor: David Wisler.

J. Eng. Gas Turbines Power 138(3), 031601 (Sep 22, 2015) (8 pages) Paper No: GTP-15-1287; doi: 10.1115/1.4031319 History: Received July 14, 2015; Revised August 04, 2015

The subject of this paper is an algorithm for a flow-adaptive measurement grid developed for pneumatic probe measurements in steady flow fields. The performance of the algorithm is demonstrated by a circumferential traverse at a constant radial position with a pneumatic five-hole probe in an annular cascade wind tunnel. Compared to a conventional equidistant measurement grid, the algorithm automatically computes the amount of measurement points needed for a high resolution of the pressure distribution in turbomachinery flows. The algorithm is fully automated and approximates the pressure distribution of a preliminary transient measurement very accurately. Even though the spacing of the computed measurement points differs significantly from an equidistant grid, postprocessing corrections related to the probe head geometry can still be applied. Accompanying a redistribution of the measurement points is a reduction in the overall points needed for the measurement. The commonly encountered problem of data oversampling is therefore avoided. Compared to a conventional equidistant measurement grid, the adaptive grid showed a significant reduction in the overall measurement points and a reduction in the duration of the measurement—while maintaining the accuracy in the computation of flow parameters. The purpose of this paper is to demonstrate the performance of an automatic detection of measurement points so that valuable measurement time can be saved without a loss in quality of the obtained data.

Copyright © 2016 by ASME
Your Session has timed out. Please sign back in to continue.


Lenherr, C. , Kalfas, A. I. , and Abhari, R. S. , 2007, “ A Flow Adaptive Aerodynamic Probe for Turbomachinery,” Meas. Sci. Technol., 18(8), pp. 2599–2608. [CrossRef]
Franken, A. R. , and Ivey, P. C. , 2006, “ Enhancing Flow Field Measurements Through Adaptive Multidimensional Data Sampling,” ASME J. Eng. Gas Turbines Power, 128(3), pp. 518–524. [CrossRef]
Schwetlick, H. , and Schütze, T. , 1995, “ Least Squares Approximation by Splines With Free Knots,” BIT Numer. Math., 35(3), pp. 361–384. [CrossRef]
Vinnemeier, F. , Simon, L. , and Koschel, W. , 1990, “ Korrektur des Kopfgeometrieeinflusses einer Fünfloch-Drucksonde auf die Meßergebnisse (Correction Method for the Head Geometry Influence of a Five-Hole Pressure Probe on the Measurement Results),” Tech. Mess., 57(JG), pp. 296–303. [CrossRef]
Parvizinia, M. , and Salchow, K. , 1993, “ Verfahren zur Korrektur des Gradientenfehlers bei Messungen mit pneumatischen Mehrlochsonden,” Technical Memorandum, Institute of Jet Propulsion and Turbomachinery, RWTH Aachen University, Aachen, Germany, Report No. TM93-10.
Bergh, H. , and Tijdeman, H. , 1965, “ Theoretical and Experimental Results for the Dynamic Response of Pressure Measuring Systems,” Nationaal Lucht-en Ruimtevaartlaboratorium, Amsterdam, Report No. NLR-TR F. 238.
Wuest, W. , 1969, Strömungsmeßtechnik, Vieweg, Braunschweig, Germany.
JCGM Working Group 1, 2008, “ Evaluation of Measurement Data—Guide to the Expression of Uncertainty in Measurement,” International Organization for Standardization, Geneva, Switzerland, Document No. JCGM 100:2008.
Dahmen, W. , and Reusken, A. , 2007, Numerik für Ingenieure und Naturwissenschaftler, Vol. 2, Springer-Verlag, Berlin.


Grahic Jump Location
Fig. 1

IST five-hole probe. (a) Probe head and (b) pressure holes and angle convection.

Grahic Jump Location
Fig. 2

Sequential steps for knot computation. (a) Transient measurement points and (b) compensation of time lag and superposition.

Grahic Jump Location
Fig. 3

Normalized expanded standard deviation depending on the number of knots distributed over four blade pitches

Grahic Jump Location
Fig. 4

Linear reconstruction of pressure distribution for all pressure holes

Grahic Jump Location
Fig. 5

Geometric illustration of projection distance d for pressure holes 1 and 3

Grahic Jump Location
Fig. 6

Flow chart of adaptive measurement grid algorithm

Grahic Jump Location
Fig. 7

Cross section of wind tunnel facility

Grahic Jump Location
Fig. 8

Comparison of highest possible resolution to reference grid

Grahic Jump Location
Fig. 9

Influence of traversing speed on superposition of transient pressure signals

Grahic Jump Location
Fig. 10

Influence of traversing speed on accuracy of flow parameter computation

Grahic Jump Location
Fig. 11

Five-hole probe raw pressures of reference and knots of adaptive grid no. 4

Grahic Jump Location
Fig. 12

Yaw angle differences of adaptive grids to reference measurement depending on the amount of knots

Grahic Jump Location
Fig. 13

Normalized standard deviation of measurement grids as a function of traversing time

Grahic Jump Location
Fig. 14

Normalized maximum difference of measurement grids as a function of knots



Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In