Predictions and Measurements of Film-Cooling on the Endwall of a First Stage Vane
|dc.contributor.author||Knost, Daniel G.||en_US|
|dc.description.abstract||In gas turbine development, the direction has been toward higher turbine inlet temperatures to increase the work output and thermal efficiency. This extreme environment can significantly impact component life. One means of preventing component burnout in the turbine is to effectively use film-cooling whereby coolant is extracted from the compressor and injected through component surfaces. One such surface is the endwall of the first stage nozzle guide vane.
This thesis details the design, prediction, and testing of two endwall film-cooling hole patterns provided by leading gas turbine engine companies. In addition a flush, two-dimensional slot was included to simulate leakage flow from the combustor-turbine interface.
The slot coolant was found to exit in a non-uniform manner leaving a large, uncooled ring around the vane. Film-cooling holes were effective at distributing coolant throughout much of the passage, but at low blowing rates were unable to provide any benefit to the critical vane-endwall junction both at the leading edge and along the pressure side. At high blowing ratios, the increased momentum of the jets induced separation at the leading edge and in the upstream portion of the passage along the pressure side, while the jets near the passage exit remained attached and penetrated completely to the vane surface.
Computational fluid dynamics (CFD) was successful at predicting coolant trajectory, but tended to under-predict thermal spreading and jet separation. Superposition was shown to be inaccurate, over-predicting effectiveness levels and thus component life, because the flow field was altered by the coolant injection.
|dc.rights||I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to Virginia Tech or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report.||en_US|
|dc.subject||gas turbine heat transfer||en_US|
|dc.title||Predictions and Measurements of Film-Cooling on the Endwall of a First Stage Vane||en_US|
|dc.description.degree||Master of Science||en_US|
|thesis.degree.name||Master of Science||en_US|
|thesis.degree.grantor||Virginia Polytechnic Institute and State University||en_US|
|dc.contributor.committeechair||Thole, Karen A.||en_US|
|dc.contributor.committeemember||Vick, Brian L.||en_US|
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