HEAT TRANSFER AND FLOW MEASUREMENTS ON A ONE-SCALE GAS TURBINE CAN COMBUSTOR MODEL

Type of Document Master's Thesis
Author Abraham, Santosh
Author's Email Address sabrah1@vt.edu
URN etd-09242008-151620
Title HEAT TRANSFER AND FLOW MEASUREMENTS ON A ONE-SCALE GAS TURBINE CAN COMBUSTOR MODEL
Degree Master of Science
Department Mechanical Engineering
Advisory Committee
Advisor Name Title
Srinath V. Ekkad Committee Chair
Danesh Tafti Committee Member
Uri Vandsburger Committee Member
Keywords

* Dry Low Emission (DLE) combustors
* Infrared Thermal Imaging
* Swirler
* Combustor liner cooing

Date of Defense 2008-08-29
Availability unrestricted
Abstract

(ABSTRACT)

Combustion designers have considered back-side impingement cooling as the solution for modern DLE combustors. The idea is to provide more cooling to the deserved local hot spots and reserve unnecessary coolant air from local cold spots. Therefore, if accurate heat load distribution on the liners can be obtained, then an intelligent cooling system can be designed to focus more on the localized hot spots. The goal of this study is to determine the heat transfer and pressure distribution inside a typical can-annular gas turbine combustor. This is one of the first efforts in the public domain to investigate the convective heat load to combustor liner due to swirling flow generated by swirler nozzles. An experimental combustor test model was designed and fitted with a swirler nozzle provided by Solar Turbines Inc. Heat transfer and pressure distribution measurements were carried out along the combustor wall to determine the thermo-fluid dynamic effects inside a combustor. The temperature and heat transfer profile along the length of the combustor liner were determined and a heat transfer peak region was established.

Constant-heat-flux boundary condition was established using two identical surface heaters, and the Infrared Thermal Imaging system was used to capture the real-time steady-state temperature distribution at the combustor liner wall. Analysis on the flow characteristics was also performed to compare the pressure distributions with the heat transfer results. The experiment was conducted at two different Reynolds numbers (Re 50,000 and Re 80,000), to investigate the effect of Reynolds Number on the heat transfer peak locations and pressure distributions. The results reveal that the heat transfer peak regions at both the Reynolds numbers occur at approximately the same location. The results from this study on a broader scale will help in understanding and predicting swirling flow effects on the local convective heat load to the combustor liner, thereby enabling the combustion engineer to design more effective cooling systems to improve combustor durability and performance.

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