THERMAL SCIENCE

International Scientific Journal

Runsheng Zhang

,

Leping Zhou

,

Shaohua Han

,

Jiangjiang Xing

,

Yuanyuan Song

,

Li Li

,

Hui Zhang

,

Xiaoze Du

ANALYSIS OF MIST/AIR FILM COOLING PERFORMANCE OF TRENCHED HOLES WITH SHAPED LIPS

ABSTRACT
Mist-assisted film cooling has exhibited great potential for efficient cooling of a turbine blade. Trench structures can significantly affect the film cooling performance of air, while their impact on the adhesion characteristics of the droplets and thus the mist-assisted film cooling performance is unclear. This work highlights the combination of these two aspects by exploring the improvement of the mist-assisted film cooling performance for trenched holes with shaped lips using 3-D computations. The results show that the upper lip structure plays a significant role in the adiabatic film cooling effectiveness, whereas the lower lip structure has little effect on it. It is found that the effect of upper lip structure on the adiabatic film cooling effectiveness increases with increasing blowing ratio. The Coanda effect makes the droplets more attached to the wall of the upper fillet lip structure and upper bevel lip structure. Meanwhile, the concentration of mist and the diameter of droplets are crucial for significantly improving the adiabatic film cooling effectiveness. In general, better adiabatic film cooling effectiveness values are observed for both 10 μm diameter droplets at a specified concentration of mist and larger concentration of mist at a specified droplet size. This work proposes a novel and efficient means of enhancing the cooling performance using mist/air mixture and trenched holes with shaped lips.
KEYWORDS
film cooling effectiveness, trench, lips, blowing ratio, mist
PAPER SUBMITTED: 2022-08-01
PAPER REVISED: 2022-10-07
PAPER ACCEPTED: 2022-10-19
PUBLISHED ONLINE: 2022-12-17
DOI REFERENCE: https://doi.org/10.2298/TSCI220801185Z
CITATION EXPORT: view in browser or download as text file
THERMAL SCIENCE YEAR 2023, VOLUME 27, ISSUE Issue 4, PAGES [2639 - 2649]
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Analysis of mist/air film cooling performance of trenched holes with shaped lips

© 2024 Society of Thermal Engineers of Serbia. Published by the Vinča Institute of Nuclear Sciences, National Institute of the Republic of Serbia, 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