Numerical investigation of a novel mushroom-shaped cooling hole for enhanced film cooling performance
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Khadidja Boualem
,
Fatima Ben Ali Kouchih
Abstract
The performance of a novel Mushroom-Shaped Cooling Hole (MSCH) configuration intended to improve the efficacy of film cooling in gas turbine components is investigated numerically in this work. Four different MSCH designs were assessed and contrasted with a standard cylindrical hole. The RNG k–ε turbulence model was used in simulations with Reynolds-Averaged Navier–Stokes (RANS) equations for a range of blowing ratios (M = 0.25–1.5). Important performance metrics were examined such as discharge coefficient flow structures and centerline and laterally averaged adiabatic film cooling effectiveness. The findings show that in comparison to the baseline MSCH configurations significantly enhance cooling performance. MSCH-3 and MSCH-4 in particular reduced discharge loss by up to 32 % and improved area-averaged film effectiveness by more than 100 %. Flow visualizations demonstrated enhanced lateral coolant spreading and the suppression of vortex pair formation. These results demonstrate how the MSCH can be a useful substitute for conventional film cooling geometries providing turbine airfoils operating under high thermal and aerodynamic loads with better thermal protection.
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Research ethics: Not applicable.
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Informed consent: Not applicable.
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Author contributions: All authors have accepted responsibility for the entire content of this manuscript and approved its submission.
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Use of Large Language Models, AI and Machine Learning Tools: None declared.
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Conflict of interest: The authors state no conflict of interest.
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Research funding: None declared.
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Data availability: Not applicable.
Nomenclature
- MSCH
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- Mushroom-Shaped Cooling Hole
- CRVP
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- CounterRotating Vortex Pairs
- D
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- film-cooling hole diameter (mm)
- L
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- spanwise dimension of the plate (mm)
- I
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- length of the injection hole (mm)
- M
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- blowing ratio
- T
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- temperature (°K)
- U
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- velocity (m/s)
- x, y, z
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- cartesian coordinate
- η
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- adiabatic film cooling effectiveness
- <η>
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- laterally averaged adiabatic effectiveness
- ρ
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- density
- ∞
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- free-stream condition
- C
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- coolant
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