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ASU Electronic Theses and Dissertations


This collection includes most of the ASU Theses and Dissertations from 2011 to present. ASU Theses and Dissertations are available in downloadable PDF format; however, a small percentage of items are under embargo. Information about the dissertations/theses includes degree information, committee members, an abstract, supporting data or media.

In addition to the electronic theses found in the ASU Digital Repository, ASU Theses and Dissertations can be found in the ASU Library Catalog.

Dissertations and Theses granted by Arizona State University are archived and made available through a joint effort of the ASU Graduate College and the ASU Libraries. For more information or questions about this collection contact or visit the Digital Repository ETD Library Guide or contact the ASU Graduate College at gradformat@asu.edu.


In order to achieve higher gas turbine efficiency, the main gas temperature at turbine inlet has been steadily increased from approximately 900°C to about 1500°C over the last few decades. This temperature is higher than the maximum acceptable temperature for turbine internals. The hot main gas may get ingested into the space between rotor and stator, the rotor-stator disk cavity in a stage because of the pressure differential between main gas annulus and the disk cavity. To reduce this ingestion, the disk cavity is equipped with a rim seal; additionally, secondary (purge) air is supplied to the cavity. Since the …

Contributors
Singh, Prashant, Roy, Ramendra P, Mignolet, Marc, et al.
Created Date
2014

Gas turbine efficiency has improved over the years due to increases in compressor pressure ratio and turbine entry temperature (TET) of main combustion gas, made viable through advancements in material science and cooling techniques. Ingestion of main combustion gas into the turbine rotor-stator disk cavities can cause major damage to the gas turbine. To counter this ingestion, rim seals are installed at the periphery of turbine disks, and purge air extracted from the compressor discharge is supplied to the disk cavities. Optimum usage of purge air is essential as purge air extraction imparts a penalty on turbine efficiency and specific …

Contributors
Michael, Mukilan Sebastiraj, Roy, Ramendra P, Mignolet, Marc P, et al.
Created Date
2015

Ingestion of high temperature mainstream gas into the rotor-stator cavities of a gas turbine is one of the major problems faced by the turbine designers. The ingested gas heats up rotor disks and induces higher thermal stresses on them, giving rise to durability concern. Ingestion is usually reduced by installing seals on the rotor and stator rims and by purging the disk cavity by secondary air bled from the compressor discharge. The geometry of the rim seals and the secondary air flow rate, together, influence the amount of gas that gets ingested into the cavities. Since the amount of secondary …

Contributors
Thiagarajan, Jayanth Kumar, Roy, Ramendra P, Lee, Taewoo, et al.
Created Date
2013

Modern day gas turbine designers face the problem of hot mainstream gas ingestion into rotor-stator disk cavities. To counter this ingestion, seals are installed on the rotor and stator disk rims and purge air, bled off from the compressor, is injected into the cavities. It is desirable to reduce the supply of purge air as this decreases the net power output as well as efficiency of the gas turbine. Since the purge air influences the disk cavity flow field and effectively the amount of ingestion, the aim of this work was to study the cavity velocity field experimentally using Particle …

Contributors
Pathak, Parag Subhash, Roy, Ramendra P, Calhoun, Ronald, et al.
Created Date
2013