dc.contributor.author	Couch, Eric L.	en
dc.contributor.committeechair	Thole, Karen A.	en
dc.contributor.committeemember	Dancey, Clinton L.	en
dc.contributor.committeemember	King, Peter S.	en
dc.contributor.department	Mechanical Engineering	en
dc.date.accessioned	2017-04-04T19:49:28Z	en
dc.date.adate	2003-08-04	en
dc.date.available	2017-04-04T19:49:28Z	en
dc.date.issued	2003-06-20	en
dc.date.rdate	2016-09-27	en
dc.date.sdate	2003-07-08	en
dc.description.abstract	In a gas turbine engine, turbine blades are exposed to temperatures above their melting point. Film-cooling and internal cooling techniques can prolong blade life and allow for higher engine temperatures. This study examines a novel cooling technique called a microcircuit, which combines internal convection and pressure side injection on a turbine blade tip. Holes on the tip called dirt purge holes expel dirt from the blade, so other holes are not clogged. Wind tunnel tests are used to observe how effectively dirt purge and microcircuit designs cool the tip. Tip gap size and blowing ratio are varied for different tip cooling configurations. Results show that the dirt purge holes provide significant film cooling on the leading edge with a small tip gap. Coolant injected from these holes impacts the shroud and floods the tip gap reducing tip leakage flow. With the addition of a microcircuit, coolant is delivered to a larger area of the tip. In all cases, cooling levels are higher for a small tip gap than a large tip gap. Increased blowing ratio does not have a dramatic effect on microcircuit film-cooling at the midchord but does improve internal cooling from the microcircuit. While the combined dirt purge holes and microcircuit cool the leading edge and midchord areas, there remains a small portion of the trailing edge that is not cooled. Also, results suggest that blowing from the microcircuit diminishes the tip leakage vortex. Overall, the microcircuit appears to be a feasible method for prolonging blade life.	en
dc.description.degree	Master of Science	en
dc.identifier.other	etd-07082003-080311	en
dc.identifier.sourceurl	http://scholar.lib.vt.edu/theses/available/etd-07082003-080311/	en
dc.identifier.uri	http://hdl.handle.net/10919/76815	en
dc.language.iso	en_US	en
dc.publisher	Virginia Tech	en
dc.rights	In Copyright	en
dc.rights.uri	http://rightsstatements.org/vocab/InC/1.0/	en
dc.subject	microcircuit	en
dc.subject	blade heat transfer	en
dc.subject	film-cooling	en
dc.subject	gas turbines	en
dc.subject	tip gap	en
dc.title	Measurements of Cooling Effectiveness Along the Tip of a Turbine Blade	en
dc.type	Thesis	en
dc.type.dcmitype	Text	en
thesis.degree.discipline	Mechanical Engineering	en
thesis.degree.grantor	Virginia Polytechnic Institute and State University	en
thesis.degree.level	masters	en
thesis.degree.name	Master of Science	en

Measurements of Cooling Effectiveness Along the Tip of a Turbine Blade

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