Design of internally cooled trailing edge at engine similar conditions- A conjugate heat transfer problem
2012 (English)In: ASME Turbo Expo 2012: Turbine Technical Conference and Exposition, ASME Press, 2012, 1357-1372 p.Conference paper (Refereed)
Gas turbines are operated at elevated temperatures as the thermal efficiency of the gas turbine is directly linked to the turbine inlet gas temperature. The different regions of the turbine blade require different means of cooling. This paper presents different designs of the two-pass trapezoidal channel which represents the trailing edge of a real engine. Engine similar boundary conditions are applied and conjugate heat transfer method is used to predict the wall temperatures. The aim is to design a cooling channel that through use of steam can reduce wall temperatures to below a target value while maintaining minimal pressure drop. The variations in design of a smooth two-pass channel were made to achieve the design target. These variations included installation of ribs at the walls, tapered divider wall, tilted divider wall and L-shaped divider wall to promote fluid impingement on the trailing wall. The results suggest that a channel with staggered ribs at the outlet pass, a tilted divider wall and impingement at the corner is the best arrangement for reducing wall temperatures below the target value; however, it has low overall aerothermal performance due to high pressure losses. A similar channel without impingement can yield acceptable results if a thermal barrier coating is applied or if a small corner of the tip-trailing edge is truncated to reduce material volume. This modification though can improve the thermal performance of the channel, is to result in higher profile and aerodynamics losses.
Place, publisher, year, edition, pages
ASME Press, 2012. 1357-1372 p.
Conjugate heat transfer, Conjugate heat transfer problem, Elevated temperature, Thermal efficiency, Thermal Performance, Trapezoidal channels, Turbine inlet gas, Wall temperatures
Research subject SRA - Energy
IdentifiersURN: urn:nbn:se:kth:diva-47349DOI: 10.1115/GT2012-68557ScopusID: 2-s2.0-84881134587ISBN: 978-079184470-0OAI: oai:DiVA.org:kth-47349DiVA: diva2:454811
ASME Turbo Expo 2012: Turbine Technical Conference and Exposition, GT 2012; Copenhagen; Denmark; 11 June 2012 through 15 June 2012
QC 201111082011-11-082011-11-082014-04-29Bibliographically approved