Large Eddy Simulation of Film Cooling with Triple Holes: Injectant Behavior and Adiabatic Film-Cooling Effectiveness
School of Mechanical Engineering, Kookmin University, 77 Jeongneung-ro, Seongbuk-gu, Seoul 02707, Korea
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Processes 2020, 8(11), 1443; https://doi.org/10.3390/pr8111443
Received: 19 October 2020
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Revised: 7 November 2020
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Accepted: 9 November 2020
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Published: 11 November 2020
(This article belongs to the Special Issue CFD Based Researches and Applications for Fluid Machinery and Fluid Device)
This study investigated the effect of adding two sister holes placed downstream the main hole on film cooling by employing large eddy simulation. Here, film-cooling flow fields from a triple-hole system inclined by 35° to a flat plate at blowing ratios of M = 0.5 and unity were simulated. Each sister hole supplies a cooling fluid at a flow rate that is a quarter of that for the main hole. The simulations were conducted using the Smagorinsky–Lilly model as the subgrid-scale model, and the results were compared with those for a single-hole system for the same amount of total cooling air and same cross-sectional area of the holes. Relative to the single-hole system, the spanwise-averaged film-cooling effectiveness in the triple-hole configuration at M = 1.0 increased by as much as 345%. The subsequent proper orthogonal decomposition analysis showed that the kinetic energy of a counter-rotating vortex pair in the triple-hole system dropped by 30–40% relative to that of the single-hole system. This indicates that the additional sister holes promoted the suppression of the mixing of the coolant jet with the mainstream flow, thus keeping the temperature of the latter low. Cross-sectional views of the root-mean-square temperature contours were also analyzed; with the results confirming that the effect of the sister holes on the jet trajectory greatly contributes in promoting film-cooling effectiveness as compared to the effect of the reduced mixing.
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Keywords:
film cooling; large eddy simulation; triple holes; blowing ratio; adiabatic film-cooling effectiveness; proper orthogonal decomposition
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MDPI and ACS Style
Baek, S.I.; Ahn, J. Large Eddy Simulation of Film Cooling with Triple Holes: Injectant Behavior and Adiabatic Film-Cooling Effectiveness. Processes 2020, 8, 1443. https://doi.org/10.3390/pr8111443
AMA Style
Baek SI, Ahn J. Large Eddy Simulation of Film Cooling with Triple Holes: Injectant Behavior and Adiabatic Film-Cooling Effectiveness. Processes. 2020; 8(11):1443. https://doi.org/10.3390/pr8111443
Chicago/Turabian StyleBaek, Seung I., and Joon Ahn. 2020. "Large Eddy Simulation of Film Cooling with Triple Holes: Injectant Behavior and Adiabatic Film-Cooling Effectiveness" Processes 8, no. 11: 1443. https://doi.org/10.3390/pr8111443
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