The present study investigates heat/mass transfer for flow through perforated plates for application to combustor wall and turbine blade film cooling. The experiments are conducted for hole length-to-diameter ratios of 0.68 to 1.5, for hole pitch-to-diameter ratios of 1.5 and 3.0, for gap distance between two parallel perforated plates of 0 to 3 hole diameters, and for Reynolds numbers of 60 to 13,700. Local heat/mass transfer coefficients near and inside the cooling holes are obtained using a naphthalene sublimation technique. Detailed knowledge of the local transfer coefficients is essential to analyze thermal stress in turbine components. The results indicate that the heat/mass transfer coefficients inside the hole surface vary significantly due to flow separation and reattachment. The transfer coefficient near the reattachment point is about four and half times that for a fully developed circular tube flow. The heat/mass transfer coefficient on the leeward surface has the same order as that on the windward surface because of a strong recirculation flow between neighboring jets from the array of holes. For flow through two in-line layers, the transfer coefficient affected by the gap spacing is approximately 100 percent higher on the windward surface of the second wall and is about 20 percent lower on the inside hole surface than that with a single layer. The transfer coefficient on the leeward surface is not affected by upstream flow conditions due probably to strong recirculation in the wake flow.

1.
Andrews
G. E.
, and
Mkpadi
M. C.
,
1984
, “
Full-Coverage Discrete Hole Wall Cooling: Discharge Coefficients
,”
ASME Journal of Engineering for Gas Turbines and Power
, Vol.
106
, pp.
183
192
.
2.
Andrews, G. E., Asere, A. A., Gupta, M. L., and Mkpadi, M. C., 1985, “Full Coverage Discrete Hole Film Cooling; The Influence of Hole Size,” ASME Paper No. 85-GT-47.
3.
Andrews
G. E.
,
Alikhanizadeh
M.
,
Asere
A. A.
,
Hussain
C. I.
,
Khoshkbar Azari
M. S.
, and
Mkpadi
M. C.
,
1986
a, “
Small Diameter Film Cooling Holes: Wall Convective Heat Transfer
,”
ASME JOURNAL OF TURBOMACHINERY
, Vol.
108
, pp.
283
289
.
4.
Andrews, G. E., Asere, A. A., Mkpadi, M. C., and Tirmahi, A., 1986b, “Transpiration Cooling: Contribution of Film Cooling to the Overall Cooling Effectiveness,” ASME Paper No. 86-GT-136.
5.
Andrews, G. E., Alikhanizadeh, M., Bazdini Tehrani, F., Hussain, C. I., and Khoshkbar Azari, M. S., 1987, “Small Diameter Film Cooling Holes: The Influence of Hole Size and Pitch,” ASME Paper No. 87-GT-28.
6.
Andrews, G. E., and Bazdidi-Tehrani, F., 1989, “Small Diameter Film Cooling Hole Heat Transfer: The Influence of the Number of Holes,” ASME Paper No. 89-GT-7.
7.
Cho, H. H., 1992, “Heat/Mass Transfer Flow Through an Array of Holes and Slits,” Ph.D. Thesis, Univ. of Minnesota.
8.
Cho
H. H.
,
Jabbari
M. Y.
, and
Goldstein
R. J.
,
1997
, “
Experimental Mass (Heat) Transfer in and Near a Circular Hole in a Flat Plate
,”
Int. J. Heat Mass Transfer
, Vol.
40
, pp.
2431
2443
.
9.
Goldstein
R. J.
, and
Cho
H. H.
,
1995
, “
A Review of Mass (Heat) Transfer Measurements Using Naphthalene Sublimation
,”
Exp. Thermal and Fluid Science
, Vol.
10
, pp.
416
434
.
10.
Hempel, H., Friedrich, R., and Wittig, S., 1980, “Full Coverage Film-Cooled Blading in High Temperature Gas Turbines: Cooling Effectiveness, Profile Loss and Thermal Efficiency,” ASME Journal of Engineering for Power, Vol. 102, No. 4.
11.
Mills
A. F.
,
1962
, “
Experimental Investigation of Turbulent Heat Transfer in the Entrance Region of a Circular Conduit
,”
J. Mech. Eng. Sci.
, Vol.
4
, pp.
63
77
.
12.
Nealy
D. A.
, and
Reider
S. B.
,
1980
, “
Evaluation of Laminated Porous Wall Materials for Combustor Liner Cooling
,”
ASME Journal of Engineering for Power
, Vol.
102
, pp.
268
276
.
13.
Ortiz, C., 1981, “Heat Transfer Coefficients for the Upstream Face of a Perforated Plate Positioned Normal to an Oncoming Flow,” M.S. Thesis, Univ. of Minnesota.
14.
Wassell, A. B., and Bhangu, J. K., 1980, “The Development and Application of Improved Combustor Wall Cooling Techniques,” ASME Paper No. 80-GT-66.
This content is only available via PDF.
You do not currently have access to this content.