0
Research Papers: Gas Turbines: Heat Transfer

Heat Transfer and Pressure Losses of W-Shaped Small Ribs at High Reynolds Numbers for Combustor Liner

[+] Author and Article Information
Tomoko Hagari, Takeo Oda, Yasushi Douura, Yasuhiro Kinoshita

 Kawasaki Heavy Industries, Ltd., 1-1 Kawasaki-cho, Akashi, Hyogo 673-8666, Japan

Katsuhiko Ishida1

 Kawasaki Heavy Industries, Ltd., 1-1 Kawasaki-cho, Akashi, Hyogo 673-8666, Japanishida_katsuhiko@khi.co.jp

1

Corresponding author.

J. Eng. Gas Turbines Power 133(9), 091901 (Apr 19, 2011) (8 pages) doi:10.1115/1.4002878 History: Received May 05, 2010; Revised August 15, 2010; Published April 19, 2011; Online April 19, 2011

The present study investigates the heat transfer performance of W-shaped ribs in a rectangular channel with typical geometries and flow conditions for a combustor liner cooling passage. In order to assess the Reynolds number dependence on heat transfer enhancement by the ribs for the combustor cooling passage, experiments were conducted with channel Reynolds number ranging from 40,000 to 550,000. The ribs were located on one side of the channel and the rib height-to-hydraulic diameter ratio (e/Dh) was 0.006–0.014, which simulate the combustor liner cooling configurations. Rib pitch-to-height ratio (P/e) was 10. Rib-roughened copper plates with constant temperature were used to measure the averaged heat transfer coefficients. Measured results show that the heat transfer enhancements of about 3 were obtained over that of a flat plate at high Reynolds numbers for all cases. The slope of heat transfer coefficient becomes constant with increasing Reynolds number because of the laminar-turbulent transition around the ribs, which is considered to occur at Reynolds number based on rib height of about 1000. Pressure loss measurements showed that the friction coefficients are constantly 3–4.5 times higher than those of a flat plate for a fully turbulent flow such as a combustor cooling passage. Pressure loss by ribs seems not to have a significant impact to the overall combustor performance. Numerical calculations were conducted additionally for all test cases. Predicted amount of heat released from the ribs contributes about 40% of the overall heat release even for low ribs. Heat transfer on the rib surface is essential in the evaluation of the rib-roughened cooling passage.

Copyright © 2011 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 1

Schematic of the experimental setup

Grahic Jump Location
Figure 3

Example of the test panel

Grahic Jump Location
Figure 4

Computational domains

Grahic Jump Location
Figure 5

Area-averaged Nusselt number of smooth channel

Grahic Jump Location
Figure 6

Area-averaged Nusselt number for a range of dimensionless rib height

Grahic Jump Location
Figure 7

Comparison of heat transfer enhancements

Grahic Jump Location
Figure 8

Comparison of friction factors

Grahic Jump Location
Figure 9

Comparison of Nusselt number based on the equivalent sand grain roughness of ribs

Grahic Jump Location
Figure 10

Calculated velocity distribution at Reynolds number of 530,000

Grahic Jump Location
Figure 11

Projected velocity vectors with normalized temperature distribution at Reynolds number of 530,000

Grahic Jump Location
Figure 12

Streamline near the ribbed wall with heat transfer enhancement distribution at Reynolds number of 530,000

Grahic Jump Location
Figure 13

Oil flow pattern on ribbed wall at Reynolds number of 530,000

Grahic Jump Location
Figure 14

Heat transfer enhancement on ribbed wall at Reynolds number of 530,000

Grahic Jump Location
Figure 15

Comparison of Nusselt number between numerical and experimental results

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