Shape optimisation of the sharp-heeled Kaplan draft tube: Performance evaluation using Computational Fluid Dynamics
Shape optimisation of the sharp-heeled Kaplan draft tube: Performance evaluation using Computational Fluid Dynamics
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DOI：
10.1016/j.renene.2020.05.164
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发表时间：
2020-06
期刊：
影响因子：
8.7
通讯作者：
S. Daniels;A. Rahat;G. Tabor;J. Fieldsend;R. Everson
中科院分区：
文献类型：
--
作者：
S. Daniels;A. Rahat;G. Tabor;J. Fieldsend;R. Everson
概述了评估弯头型尾水管性能的方法。这是通过使用计算流体动力学 (CFD) 来评估尾水管设计中的压力恢复和机械能损失，同时使用开源和商业软件来参数化和重新生成几何形状和 CFD 网格来实现的。对弯头型尾水管进行了初步验证研究，重点关注网格再生方法、稳态假设和湍流建模方法，以评估设计效率。网格收敛指数（GCI）技术用于评估压力恢复到网格分辨率的不确定性。研究发现，通过面积加权平均来估计压力恢复可以显着降低网格带来的不确定性。同时，人们发现这种不确定性随着几何形状上的局部横截面积而波动。随后，对流入锥体和外跟设计对流场和压力恢复的影响进行了研究。 Catmull-Rom 样条用于参数化这些组件，以便从文献中重新创建许多提议的设计。 GCI 分析也适用于这些设计，证明了网格再生方法的稳健性。
A methodology to assess the performance of an elbow-type draft tube is outlined. This was achieved using Computational Fluid Dynamics (CFD) to evaluate the pressure recovery and mechanical energy losses along a draft tube design, while using open-source and commercial software to parameterise and regenerate the geometry and CFD grid. An initial validation study of the elbow-type draft tube is carried out, focusing on the grid-regeneration methodology, steady-state assumption, and turbulence modelling approach for evaluating the design’s efficiency. The Grid Convergence Index (GCI) technique was used to assess the uncertainty of the pressure recovery to the grid resolution. It was found that estimating the pressure recovery through area-weighted averaging significantly reduced the uncertainty due to the grid. Simultaneously, it was found that this uncertainty fluctuated with the local cross-sectional area along the geometry. Subsequently, a study of the inflow cone and outer-heel designs on the flowfield and pressure recovery was carried out. Catmull-Rom splines were used to parameterise these components, so as to recreate a number of proposed designs from the literature. GCI analysis is also applied to these designs, demonstrating the robustness of the grid-regeneration methodology.