标题： 基于计算流体动力学的超高压水射流喷嘴结构优化方法 显示英文标题

标题： Computational fluid dynamics-based structure optimization of ultra-high-pressure water-jet nozzle using approximation method

摘要： 由于超高压（UHP）水射流喷嘴的几何结构是提高其水动力性能的关键因素，因此获得适合的UHP水射流喷嘴几何结构至关重要。在本研究中，通过集成近似模型开发了一个基于CFD的UHP喷嘴结构优化循环，以优化喷嘴结构以增加径向峰值壁面剪切应力。为了提高麻雀搜索算法（SSA）的优化精度，提出了一种增强版本，称为Logistic-Tent混沌麻雀搜索算法（LTC-SSA）。LTC-SSA算法利用了由Logistic和Tent映射组合设计的Logistic-Tent混沌（LTC）映射。这种方法旨在通过增加麻雀种群的多样性来克服SSA算法的“过早收敛”缺点。此外，为了提高峰值壁面剪切应力的预测精度，提出了一种基于LTC-SSA支持向量机（SVM）的数据预测方法。在此，LTC-SSA算法用于训练SVM模型的惩罚系数C和参数gamma g。为了构建LTC-SSA-SVM模型，使用最优拉丁超立方设计（Opt LHD）来设计采样喷嘴结构，并通过CFD方法计算这些喷嘴结构的峰值壁面剪切应力（目标函数）。为了本文的目的，该优化框架已被用于优化原始喷嘴结构。结果表明，本研究开发的优化框架可以用来优化喷嘴结构，显著提高其水动力性能。 显示英文摘要

摘要： Since the geometry structure of ultra-high-pressure (UHP) water-jet nozzle is a critical factor to enhance its hydrodynamic performance, it is critical to obtain a suitable geometry for a UHP water jet nozzle. In this study, a CFD-based optimization loop for UHP nozzle structure has been developed by integrating an approximate model to optimize nozzle structure for increasing the radial peak wall shear stress. In order to improve the optimization accuracy of the sparrow search algorithm (SSA), an enhanced version called the Logistic-Tent chaotic sparrow search algorithm (LTC-SSA) is proposed. The LTC-SSA algorithm utilizes the Logistic-Tent Chaotic (LTC) map, which is designed by combining the Logistic and Tent maps. This new approach aims to overcome the shortcoming of "premature convergence" for the SSA algorithm by increasing the diversity of the sparrow population. In addition, to improve the prediction accuracy of peak wall shear stress, a data prediction method based on LTC-SSA-support vector machine (SVM) is proposed. Herein, LTC-SSA algorithm is used to train the penalty coefficient C and parameter gamma g of SVM model. In order to build LTC-SSA-SVM model, optimal Latin hypercube design (Opt LHD) is used to design the sampling nozzle structures, and the peak wall shear stress (objective function) of these nozzle structures are calculated by CFD method. For the purpose of this article, this optimization framework has been employed to optimize original nozzle structure. The results show that the optimization framework developed in this study can be used to optimize nozzle structure with significantly improved its hydrodynamic performance.