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% higher on the windward surface of the second wall and is about 20% 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 to probably strong recirculation in the wake flow.
|Title of host publication||Heat Transfer; Electric Power; Industrial and Cogeneration|
|Publisher||American Society of Mechanical Engineers (ASME)|
|Publication status||Published - 1995|
|Event||ASME 1995 International Gas Turbine and Aeroengine Congress and Exposition, GT 1995 - Houston, United States|
Duration: 1995 Jun 5 → 1995 Jun 8
|Name||Proceedings of the ASME Turbo Expo|
|Other||ASME 1995 International Gas Turbine and Aeroengine Congress and Exposition, GT 1995|
|Period||95/6/5 → 95/6/8|
Bibliographical noteFunding Information:
Support from the Air Force Office of Scientific Research and through the Engineering Research Program of the Department of Energy aided greatly in the conduct of this study.
Copyright © 1995 by ASME All Rights Reserved.
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