0
Research Papers: Forced Convection

Geometrical Optimization and Experimental Validation of a Tripod Film Cooling Hole With Asymmetric Side Holes

[+] Author and Article Information
Zhongran Chi

School of Mechanical Engineering,
Shanghai Jiao Tong University,
Shanghai 200240, China
e-mail: chizr@sjtu.edu.cn

Jing Ren, Hongde Jiang

Department of Thermal Engineering,
Tsinghua University,
Beijing 100084, China

Shusheng Zang

School of Mechanical Engineering,
Shanghai Jiao Tong University,
Shanghai 200240, China

Contributed by the Heat Transfer Division of ASME for publication in the JOURNAL OF HEAT TRANSFER. Manuscript received September 25, 2014; final manuscript received January 10, 2016; published online March 22, 2016. Assoc. Editor: Gongnan Xie.

J. Heat Transfer 138(6), 061701 (Mar 22, 2016) (12 pages) Paper No: HT-14-1639; doi: 10.1115/1.4032883 History: Received September 25, 2014; Revised January 10, 2016

A tripod cylindrical film hole with asymmetric side holes is studied numerically and experimentally on a flat plate for higher film cooling effectiveness. First, the influences of geometrical parameters are studied and the optimum configurations of the asymmetric tripod hole are found in a design of experiments (DoE) optimization study based on an improved numerical model for film cooling prediction, in which more than 100 3D computational fluid dynamics (CFD) simulations are carried out. Then, one optimum configuration of the asymmetric tripod hole is examined experimentally using pressure-sensitive paint (PSP) measurements and compared to the experimental results of the simple cylindrical film hole and a well-designed shaped film hole. The flow and heat transferring characteristics of the asymmetric tripod holes were explored from the DoE results. The side holes can form a shear vortex system or an antikidney vortex system when proper spanwise distances between them are adopted, which laterally transports the coolant and form a favorable coolant coverage. According to the experimental results on flat plate, the optimal configuration of the asymmetric tripod hole is significantly better than cylindrical hole, especially at high blowing ratios. Furthermore, it can provide equivalent or even higher film cooling effectiveness than a well-designed shaped hole.

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

References

Figures

Grahic Jump Location
Fig. 1

Secondary flow structures on cross section (downstream): (a) kidney vortices pair and (b) antikidney vortices pair

Grahic Jump Location
Fig. 2

Geometry of the asymmetric tripod film cooling holes: (a) top view and (b) isometric view. 1—entrance of the hole, 2—tripod branching, 3—exit of side hole #1, 4—exit of side hole #2, and 5—exit of middle hole.

Grahic Jump Location
Fig. 3

Automatically generated mesh of one tripod film cooling hole: (a) overall view, (b) partial view near the film holes, and (c) sectional view at the hole exit

Grahic Jump Location
Fig. 4

Experimental validation of film cooling effectiveness distribution predicted by ansys cfx [22]: (a) centerline and (b) spanwisely averaged

Grahic Jump Location
Fig. 5

Area averaging of film cooling effectiveness distribution

Grahic Jump Location
Fig. 6

Effects of each design variable on the area average film cooling effectiveness

Grahic Jump Location
Fig. 7

Predicted film cooling effectiveness distributions of nine cases: (a) I: a1 = 1.5, a2 = 2.0, a3 = −0.5, a4 = 0.5, and ηave = 0.289; (b) II: a1 = 1.5, a2 = 2.5, a3 = 0, a4 = 0, and ηave = 0.217; (c) III: a1 = 1.5, a2 = 3.0, a3 = 0, a4 = 0.5, and ηave = 0.330; (d) IV: a1 = 1.5, a2 = 2.0, a3 = 0, a4 = 0.5, and ηave = 0.286; (e) V: a1 = 1.5, a2 = 2.5, a3 = 0, a4 = 0.5, and ηave = 0.330; (f) VI: a1 = 1.0, a2 = 2.5, a3 = 0.5, a4 = 0.75, and ηave = 0.318; (g) VII: a1 = 1.5, a2 = 2.0, a3 = 0.5, a4 = 0.5, and ηave = 0.254; (h) VIII: a1 = 1.5, a2 = 2.5, a3 = 0, a4 = 1.0, and ηave = 0.309; and (i) IX: a1 = 2.0, a2 = 2.5, a3 = 0.5, a4 = 0.75, and ηave = 0.295

Grahic Jump Location
Fig. 8

Three-dimensional streamlines and temperature contours at different streamwise locations: (a) case II: a1 = 1.5, a2 = 2.5, a3 = 0, and a4 = 0; (b) case V: a1 = 1.5, a2 = 2.5, a3 = 0, and a4 = 0.5; and (c) case VIII: a1 = 1.5, a2 = 2.5, a3 = 0, and a4 = 1.0

Grahic Jump Location
Fig. 9

Three-dimensional streamlines and streamwise vorticity contours at different streamwise locations: (a) case II: a1 = 1.5, a2 = 2.5, a3 = 0, and a4 = 0; (b) case V: a1 = 1.5, a2 = 2.5, a3 = 0, and a4 = 0.5; and (c) case VIII: a1 = 1.5, a2 = 2.5, a3 = 0, and a4 = 1.0

Grahic Jump Location
Fig. 10

Secondary flow structure of shear vortices on cross section (downstream)

Grahic Jump Location
Fig. 18

Spanwisely averaged distributions of η: (a) BR = 0.5, (b) BR = 1.0, (c) BR = 1.5, and (d) BR = 2.0

Grahic Jump Location
Fig. 15

Geometries of the tested film cooling holes: (a) cylindrical, (b) shaped, and (c) asymmetric tripod

Grahic Jump Location
Fig. 14

PSP calibration curves

Grahic Jump Location
Fig. 13

Test section with LED lights

Grahic Jump Location
Fig. 11

Schematic view of the test rig

Grahic Jump Location
Fig. 17

Distributions of η on the plate: (a) BR = 0.5, (b) BR = 1.0, (c) BR = 1.5, and (d) BR = 2.0

Grahic Jump Location
Fig. 16

Comparison of area average film cooling effectiveness measured by PSP

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