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A broad reconsideration of anti-vortex film cooling method using numerical optimization and an improved heat-flux model
Chaharlang Kiani, K ; Sharif University of Technology | 2021
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- Type of Document: Article
- DOI: 10.1016/j.ijheatfluidflow.2021.108815
- Publisher: Elsevier B.V , 2021
- Abstract:
- This paper represents the detailed results of an evolutionary optimization framework towards the exploration of vortex mechanisms leading to effective anti-vortex film cooling. In this regards, several arrangements of triple cooling holes were studied on flat and curved geometries using differential-evolution optimization algorithm and a modified Reynolds-stress based flow solver. Depending on the flow and geometric parameters, four distinct types of vortex interaction with different cooling mechanisms were identified. The vortex-trapping mechanism, observed in the optimized upstream arrangement acts through imposing a mild downwash over the main counter-rotating vortex pair and provides the best cooling effectiveness for the low injection angle (less than 30°) cases. The vortex-suppression and -balancing are the optimal possible solutions of the adjacent arrangement. The latter is the classic well-known type of anti-vortex cooling, while the former provides a sudden strong controlling potential for high blowing ratios (higher than 1.0) and high injection angle film cooling. For the non-flat surfaces the triple holes effectively perform up to blowing-ratio of 2.0. However, the reverse-vortex-trapping mechanism occurring in the downstream arrangement is recommended for convex surfaces, while the adjacent arrangement is the choice for concave regions. In general, there is a possibility of reducing the coolant consumption about 30% through increasing the pitch-to-diameter ratio, while the values of cooling-effectiveness still remain in an acceptable range. © 2021 Elsevier Inc
- Keywords:
- Cooling ; Evolutionary algorithms ; Heat flux ; Numerical methods ; Optimization ; Reynolds number ; Cooling effectiveness ; Counter-rotating Vortex Pair ; Differential evolution optimization algorithms ; Evolutionary optimizations ; Numerical optimizations ; Pitch-to-diameter ratios ; Trapping mechanisms ; Vortex interactions ; Vortex flow
- Source: International Journal of Heat and Fluid Flow ; Volume 89 , 2021 ; 0142727X (ISSN)
- URL: https://www.sciencedirect.com/science/article/abs/pii/S0142727X2100045X