The present study investigates heat/mass transfer for flow through per
forated plates for application to combustor wall and turbine blade fil
m cooling. The experiments are conducted for hole length-to-diameter r
atios 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 ho
le diameters, and for Reynolds numbers of 60 to 13,700. Local heat/mas
s 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 c
oefficients inside the hole surface vary significantly due to flow sep
aration and reattachment. The transfer coefficient near the reattachme
nt point is about four and half times that for a fully developed circu
lar tube flow. The heat/mass transfer coefficient on the leeward surfa
ce has the same order as that on the windward surface because of a str
ong recirculation flow between neighboring jets from the array of hole
s. For flow through two in-line layers, the transfer coefficient affec
ted by the gap spacing is approximately 100 percent higher on the wind
ward surface of the second wall and is about 20 percent lower on the i
nside hole surface than that with a single layer. The transfer coeffic
ient on the leeward surface is not affected by upstream flow condition
s due probably to strong recirculation in the wake flow.