1. An inverse optimization of turbulent flow and heat transfer for a cooling passage with hierarchically arranged ribs in turbine blades.
- Author
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Zheng, Shao-Fei, Lian, We-Kai, Meng, Jia-Xing, Wang, He-Chen, Gao, Shu-Rong, Yang, Yan-Ru, Li, Hai-Wang, Sunden, Bengt, and Wang, Xiao-Dong
- Subjects
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HEAT transfer in turbulent flow , *TURBINE blades , *HEAT convection , *HEAT transfer , *HEAT losses - Abstract
• A multi-parameter optimization method is developed based on the simplified conjugate-gradient algorithm. • Heights of perturbation ribs in turbine blade internal cooling are optimized at various conditions. • All of the optimal designs possess a hierarchically nonuniform characteristic. • The design direction is provided for perturbation elements involving turbulent flow heat transfer. Owing to the limited cold-air amount and pressure in supply systems, high-efficient heat transfer with low-level friction loss is highly desired for cooling units of a turbine blade. To exploit the potential improvement of hierarchically arranged ribs in cooling passages proposed previously, multi-parameter optimizations for rib arrangements are implemented by integrating the simplified conjugate-gradient algorithm with the turbulent flow and heat transfer model. Rib heights as design variables are optimized with various performance indices as objective functions at a fixed Re. The optimizations confirm that using the wall temperature difference and Nu as the objective function, respectively, a limited heat transfer improvement is achieved with a greatly increased friction loss. Taking the overall performance factor as the objective function, different optimal designs at different constraint conditions possess hierarchical characteristics. A significant friction loss reduction of 52.1%, 54.7%, and 54.8%, is achieved with a moderate heat transfer loss of 10.9%, 7.0%, and 2.3%. Despite different thermal and friction performances, their overall performances are consistent with a remarkable increase of 13.9%, 21.2%, and 27.3%. Finally, the optimization strategy coupling the multi-parameter optimization and hierarchical scheme is confirmed as effective for enhancing the thermohydraulic performance of convective heat transfer systems with perturbation elements. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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