Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 6 of 6
Full-Text Articles in Entire DC Network
Multi-Row Film Cooling Boundary Layers, Greg Natsui
Multi-Row Film Cooling Boundary Layers, Greg Natsui
Electronic Theses and Dissertations
High fidelity measurements are necessary to validate existing and future turbulence models for the purpose of producing the next generation of more efficient gas turbines. The objective of the present study is to conduct several different measurements of multi-row film cooling arrays in order to better understand the physics involved with injection of coolant through multiple rows of discrete holes into a flat plate turbulent boundary layer. Adiabatic effectiveness distributions are measured for several multi-row film cooling geometries. The geometries are designed with two different hole spacings and two different hole types to yield four total geometries. One of the …
A Full Coverage Film Cooling Study: The Effect Of An Alternating Compound Angle, Justin Hodges
A Full Coverage Film Cooling Study: The Effect Of An Alternating Compound Angle, Justin Hodges
Electronic Theses and Dissertations
This thesis is an experimental and numerical full-coverage film cooling study. The objective of this work is the quantification of local heat transfer augmentation and adiabatic film cooling effectiveness for two full-coverage film cooling geometries. Experimental data was acquired with a scientific grade CCD camera, where images are taken over the heat transfer surface, which is painted with a temperature sensitive paint. The CFD component of this study served to evaluate how well the v2-f turbulence model predicted film cooling effectiveness throughout the array, as compared with experimental data. The two staggered arrays tested are different from one another through …
Coupled Usage Of Discrete Hole And Transpired Film For Better Cooling Performance, Michael Torrance
Coupled Usage Of Discrete Hole And Transpired Film For Better Cooling Performance, Michael Torrance
Electronic Theses and Dissertations
Electricity has become so ingrained in everyday life that the current generation has no knowledge of life without it. The majority of power generation in the United States is the result of turbines of some form. With such widespread utilization of these complex rotating machines, any increase in efficiency translates into improvements in the current cost of energy. These improvements manifest themselves as reductions in greenhouse emissions or possible savings to the consumer. The most important temperature regarding turbine performance is the temperature of the hot gas entering the turbine, denoted turbine inlet temperature. Increasing the turbine inlet temperature allows …
Study Of Film Cooling Effectiveness: Conical, Trenched And Asymmetrical Shaped Holes, Humberto Zuniga
Study Of Film Cooling Effectiveness: Conical, Trenched And Asymmetrical Shaped Holes, Humberto Zuniga
Electronic Theses and Dissertations
Film cooling is a technique whereby air from the compressor stage of a gas turbine engine is diverted for cooling purposes to parts, such as the turbine stage, that operate at very high temperatures. Cooling arrangements include impingement jets, finned, ribbed and turbulated channels, and rows of film cooling holes, all of which over the years have become progressively more complex. This costly, but necessary complexity is a result of the industry's push to run engines at increasingly higher turbine inlet temperatures. Higher temperatures mean higher efficiency, but they also mean that the turbine first stage operates hundreds of degrees …
Effect Of Pressure Gradient And Wake On Endwall Film Cooling Effectiveness, Sylvette Rodriguez
Effect Of Pressure Gradient And Wake On Endwall Film Cooling Effectiveness, Sylvette Rodriguez
Electronic Theses and Dissertations
Endwall film cooling is a necessity in modern gas turbines for safe and reliable operation. Performance of endwall film cooling is strongly influenced by the hot gas flow field, among other factors. For example, aerodynamic design determines secondary flow vortices such as passage vortices and corner vortices in the endwall region. Moreover blockage presented by the leading edge of the airfoil subjects the incoming flow to a stagnating pressure gradient leading to roll-up of the approaching boundary layer and horseshoe vortices. In addition, for a number of heavy frame power generation gas turbines that use cannular combustors, the hot and …
Preliminary Study On The Impact Of Impingement On The Effectiveness Of Film Cooling In The Presence Of Gas Path Pressure Gradient, Anil Peravali
Preliminary Study On The Impact Of Impingement On The Effectiveness Of Film Cooling In The Presence Of Gas Path Pressure Gradient, Anil Peravali
Electronic Theses and Dissertations
Impingement is the most commonly used method of cooling in the hot stages of gas turbines. This is often combined with film cooling to further increase the cooling performance. The mainstream flow where in the coolant films discharge often has large stream wise pressure variations. All existing studies on coupled film and impingement cooling concentrated on the effect of the film depletion on the impingement heat transfer. This study investigates the impact of impingement on film cooling, where the jets impinging on a flat plate are depleted through arrays of film cooling holes in the presence of pressure gradient in …