0
Research Papers

Effect of Varying Jet Diameter on the Heat Transfer Distributions of Narrow Impingement Channels

[+] 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@me.com

Peter Ott

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

Magali Cochet

Alstom Power,
Baden CH-5401, Switzerland

Jens von Wolfersdorf, Bernhard Weigand

Institute of Aerospace Thermodynamics (ITLR),
University of Stuttgart,
Stuttgart D-70569, Germany

Contributed by the International Gas Turbine Institute (IGTI) of ASME for publication in the JOURNAL OF TURBOMACHINERY. Manuscript received July 18, 2014; final manuscript received July 19, 2014; published online September 10, 2014. Editor: Ronald Bunker.

J. Turbomach 137(2), 021004 (Sep 10, 2014) (9 pages) Paper No: TURBO-14-1155; doi: 10.1115/1.4028294 History: Received July 18, 2014; Revised July 19, 2014

The development of integrally cast turbine airfoils allows the production of narrow impingement channels in a double-wall configuration, where the coolant is practically injected within the wall of the airfoil providing increased heat transfer capabilities. This study examines the cooling performance of narrow impingement channels with varying jet diameters using a single exit design in an attempt to regulate the generated crossflow. The channel consists of a single row of five inline jets tested at two different channel heights and over a range of engine representative Reynolds numbers. Detailed heat transfer coefficient distributions are evaluated over the complete interior surfaces of the channel using the transient liquid crystal technique. Additionally, local jet discharge coefficients are determined by probe traversing measurements for each individual jet. A 10%-increasing and a 10%-decreasing jet diameter pattern are compared with a baseline geometry of uniform jet size distribution, indicating a considerable effect of varying jet diameter on the heat transfer level and the development of the generated crossflow.

FIGURES IN THIS ARTICLE
<>
Copyright © 2015 by ASME
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Fig. 1

Narrow impingement cooling cavities within a turbine airfoil wall

Grahic Jump Location
Fig. 2

Impingement cooling test facility

Grahic Jump Location
Fig. 3

Narrow impingement channel models

Grahic Jump Location
Fig. 4

Schematic representation of pressure measurement points (a) 10%—increasing jet diameter, (b) uniform jet diameter, and (c) 10%—decreasing jet diameter

Grahic Jump Location
Fig. 5

Jet axial velocity profiles (y-direction): (a) 10%—increasing jet diameter; (b) uniform jet diameter; (c) 10%—decreasing jet diameter

Grahic Jump Location
Fig. 6

Local jet discharge coefficients at ReD = 23,780, (a) ReD,j variation and (b) Gcf development

Grahic Jump Location
Fig. 7

(a) ReD,j variation and (b) Gcf development

Grahic Jump Location
Fig. 8

Heat transfer coefficient surface contours (h/href) for the target plate and the sidewalls at ReD = 23,780: (a) Z/D = 1.5 and (b) Z/D = 3

Grahic Jump Location
Fig. 9

Local Nusselt number distributions on the channel centerline (y = 0) for the target plate at ReD = 23,780: (a) Z/D = 1.5 and (b) Z/D = 3

Grahic Jump Location
Fig. 10

Heat transfer coefficient surface contours (h/href) for the impingement plate at ReD = 23,780: (a) Z/D = 1.5 and (b) Z/D = 3

Grahic Jump Location
Fig. 11

Spanwise averaged NuD distributions for all channel walls at ReD = 23,780: (a) target plate, Z/D = 1.5; (b) sidewall, Z/D = 1.5; (c) impingement plate, Z/D = 1.5; (d) target plate, Z/D = 3; (e) sidewall, Z/D = 3; and (f) impingement plate, Z/D = 3

Grahic Jump Location
Fig. 12

Area averaged NuD as a function of jet average Reynolds number for all channel walls: (a) Z/D = 1.5 and (b) Z/D = 3

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