0
Research Papers: Forced Convection

Hole Staggering Effect on the Cooling Performance of Narrow Impingement Channels Using the Transient Liquid Crystal Technique

[+] Author and Article Information
Alexandros Terzis

Group of Thermal Turbomachinery (GTT),
École Polytechnique Fédérale
de Lausanne (EPFL),
Lausanne CH-1015, Switzerland
e-mail: alexandros.terzis@epfl.ch

Guillaume Wagner

Alstom,
Baden CH-5401, Switzerland

Jens von Wolfersdorf

Institute of Aerospace Thermodynamics (ITLR),
Universität Stuttgart,
Pfaffenwaldring 31,
D-70569 Stuttgart, Germany

Peter Ott

Group of Thermal Turbomachinery (GTT),
École Polytechnique Fédérale
de Lausanne (EPFL),
Lausanne CH-1015, Switzerland

Bernhard Weigand

Institute of Aerospace Thermodynamics (ITLR),
Universität Stuttgart,
Pfaffenwaldring 31,
Stuttgart D-70569, Germany

Contributed by the Heat Transfer Division of ASME for publication in the JOURNAL OF HEAT TRANSFER. Manuscript received September 3, 2012; final manuscript received March 18, 2014; published online April 8, 2014. Assoc. Editor: Terry Simon.

J. Heat Transfer 136(7), 071701 (Apr 08, 2014) (9 pages) Paper No: HT-12-1477; doi: 10.1115/1.4027250 History: Received September 03, 2012; Revised March 18, 2014

This study examines experimentally the cooling performance of narrow impingement channels as could be cast-in in modern turbine airfoils. Full surface heat transfer coefficients are evaluated for the target plate and the sidewalls of the channels using the transient liquid crystal technique. Several narrow impingement channel geometries, consisting of a single row of five cooling holes, have been investigated composing a test matrix of nine different models. The experimental data are analyzed by means of various post-processing procedures aiming to clarify and quantify the effect of cooling hole offset position from the channel centerline on the local and average heat transfer coefficients and over a range of Reynolds numbers (11,100–86,000). The results indicated a noticeable effect of the jet pattern on the distribution of convection coefficients as well as similarities with conventional multi-jet impingement cooling systems.

FIGURES IN THIS ARTICLE
<>
Copyright © 2014 by ASME
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Fig. 1

Cast-in cooling channels in a turbine airfoil. Adopted from Lutum et al. [1].

Grahic Jump Location
Fig. 2

Impingement cooling test facility

Grahic Jump Location
Fig. 4

Plenum temperature history, ReD = 32,400, ΔT = 40 K

Grahic Jump Location
Fig. 3

Test models and impingement jet patterns

Grahic Jump Location
Fig. 9

Stagnation point lines

Grahic Jump Location
Fig. 5

Local NuD distribution on the centerline of the target plate for all examined ReD, X/D = Y/D = 5, Δy/Y = 0, (a) Z/D=1 and (b) Z/D=3

Grahic Jump Location
Fig. 6

Exponent m surface contours for the inline jet patterns (a) Z/D = 1, (b) Z/D = 2, and (c) Z/D = 3

Grahic Jump Location
Fig. 8

Local NuD distributions for different jet patterns. ReD = 32,400, X/D = Y/D = 5, (a) Z/D=1 and (b) Z/D=3.

Grahic Jump Location
Fig. 7

Heat transfer coefficient surface contours on the target plate and the sidewalls. X/D = Y/D = 5. ReD = 32,400, Δy/Y = 0: (a) Z/D = 1, (b) Z/D = 2, and (c) Z/D = 3; Δy/Y = 0.4: (d) Z/D = 1, (e) Z/D = 2, and (f) Z/D = 3; Δy/Y = 0.76: (g) Z/D = 1, (h) Z/D = 2, and (i) Z/D = 3.

Grahic Jump Location
Fig. 10

Spanwise-averaged NuD distributions for different jet patterns. ReD = 32,400, X/D = Y/D = 5, (a) Z/D=1 and (b) Z/D=3.

Grahic Jump Location
Fig. 11

Target plate and sidewall area averaged NuD as a function of ReD

Grahic Jump Location
Fig. 12

Channel pressure drop for all Z/D. Closed points: Δy/Y = 0, open points: Δy/Y = 0.76.

Tables

Errata

Discussions

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