THERMAL SCIENCE

International Scientific Journal

EFFECT OF COMBINED HOLE CONFIGURATION ON FILM COOLING WITH AND WITHOUT MIST INJECTION

ABSTRACT
Turbine blades operate under a harsh environmental condition, and the inlet temperature of gas turbines is increasing with requirement of high engine efficiency. Some cooling schemes are adopted to prevent these blades from the thermal erosion of the hot mainstream. Film cooling technology is used widely and effectively in gas turbines. The coolant air is suppressed to the wall by the main-stream after jetting out of the film hole. A new hole configuration is first pro-posed to improve the film cooling characteristics in this paper. Comparison be-tween a conventional cylindrical hole and a new combined hole is conducted by CFD, and effects of various blowing ratios and droplet sizes are also investigated. Results show that the combined hole configuration provides a wider coverage than that in the cylindrical hole configuration case at high blowing ratios (M = 1.0 and M = 1.5). In addition, the film cooling with mist injection also provides a significant enhancement on cooling performance especially for the combined hole case with a small droplet size (10−5 m).
KEYWORDS
PAPER SUBMITTED: 2017-12-28
PAPER REVISED: 2018-03-11
PAPER ACCEPTED: 2018-03-12
PUBLISHED ONLINE: 2018-09-23
DOI REFERENCE: https://doi.org/10.2298/TSCI171228266T
CITATION EXPORT: view in browser or download as text file
THERMAL SCIENCE YEAR 2018, VOLUME 22, ISSUE 5, PAGES [1923 - 1931]
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© 2018 Society of Thermal Engineers of Serbia. Published by the Vinča Institute of Nuclear Sciences, Belgrade, Serbia. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International licence