{"title":"一种模拟自适应喷管产生离散阵风的动态浸入边界方法","authors":"K. Boulbrachene, M. Breuer","doi":"10.1016/j.compfluid.2025.106775","DOIUrl":null,"url":null,"abstract":"<div><div>The recently developed wind gust generator, the <em>adaptive nozzle</em> (Wood and Breuer, 2025) , features a nozzle with a fully rotatable upper contour, enabling a smooth gust generation with low unwanted flow disturbances. While preserving the underlying gust-generation principle of its predecessor, the new design significantly reduces pressure losses caused by flow blockage and preserves the original horizontal trajectory of the flow along the streamwise direction. While experiments have validated the improved design, a comprehensive numerical analysis is crucial to resolve the three-dimensional flow fields across the entire computational domain. This shall also facilitate capturing the resulting transient aerodynamic loads on a wind tunnel specimen — quantities difficult to measure experimentally. To accurately capture the complex flow dynamics, high-fidelity large-eddy simulations are conducted, modeling the nozzle’s upper contour as a dynamic immersed boundary (IB). A curvilinear Eulerian grid is employed to ensure both efficient and precise spatial resolution of the problem. The moving least-squares (MLS) version of the direct forcing IB approach (Vanella and Balaras, 2009) is used to construct an IB kernel for each Lagrangian marker. Additionally, the MLS approach is also applied to construct one-sided kernel functions for Lagrangian points near the boundaries of the computational domain. Challenges related to the efficient IB simulation on curvilinear grids are addressed, and a solution is proposed within the MLS framework. The predicted results are analyzed in detail and validated against the experimental data by Wood and Breuer (2025) , providing insights into the effectiveness of the new design in generating controlled wind gusts.</div></div>","PeriodicalId":287,"journal":{"name":"Computers & Fluids","volume":"301 ","pages":"Article 106775"},"PeriodicalIF":3.0000,"publicationDate":"2025-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"A dynamic immersed boundary method for simulating an adaptive nozzle generating discrete wind gusts\",\"authors\":\"K. Boulbrachene, M. Breuer\",\"doi\":\"10.1016/j.compfluid.2025.106775\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>The recently developed wind gust generator, the <em>adaptive nozzle</em> (Wood and Breuer, 2025) , features a nozzle with a fully rotatable upper contour, enabling a smooth gust generation with low unwanted flow disturbances. While preserving the underlying gust-generation principle of its predecessor, the new design significantly reduces pressure losses caused by flow blockage and preserves the original horizontal trajectory of the flow along the streamwise direction. While experiments have validated the improved design, a comprehensive numerical analysis is crucial to resolve the three-dimensional flow fields across the entire computational domain. This shall also facilitate capturing the resulting transient aerodynamic loads on a wind tunnel specimen — quantities difficult to measure experimentally. To accurately capture the complex flow dynamics, high-fidelity large-eddy simulations are conducted, modeling the nozzle’s upper contour as a dynamic immersed boundary (IB). A curvilinear Eulerian grid is employed to ensure both efficient and precise spatial resolution of the problem. The moving least-squares (MLS) version of the direct forcing IB approach (Vanella and Balaras, 2009) is used to construct an IB kernel for each Lagrangian marker. Additionally, the MLS approach is also applied to construct one-sided kernel functions for Lagrangian points near the boundaries of the computational domain. Challenges related to the efficient IB simulation on curvilinear grids are addressed, and a solution is proposed within the MLS framework. The predicted results are analyzed in detail and validated against the experimental data by Wood and Breuer (2025) , providing insights into the effectiveness of the new design in generating controlled wind gusts.</div></div>\",\"PeriodicalId\":287,\"journal\":{\"name\":\"Computers & Fluids\",\"volume\":\"301 \",\"pages\":\"Article 106775\"},\"PeriodicalIF\":3.0000,\"publicationDate\":\"2025-08-06\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Computers & Fluids\",\"FirstCategoryId\":\"5\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S004579302500235X\",\"RegionNum\":3,\"RegionCategory\":\"工程技术\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"COMPUTER SCIENCE, INTERDISCIPLINARY APPLICATIONS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Computers & Fluids","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S004579302500235X","RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"COMPUTER SCIENCE, INTERDISCIPLINARY APPLICATIONS","Score":null,"Total":0}
引用次数: 0
摘要
最近开发的阵风发生器,自适应喷嘴(Wood and Breuer, 2025),其特点是喷嘴具有完全可旋转的上部轮廓,能够以低不必要的流动干扰平滑地产生阵风。在保留其前身的潜在阵风产生原理的同时,新设计显着减少了由流动阻塞引起的压力损失,并保留了沿流方向的原始水平流动轨迹。虽然实验已经验证了改进的设计,但全面的数值分析对于解决整个计算域的三维流场至关重要。这也将有助于捕获风洞样品上产生的瞬态气动载荷-难以通过实验测量的数量。为了准确地捕捉复杂的流动动力学,进行了高保真的大涡模拟,将喷嘴的上轮廓建模为动态浸入边界(IB)。采用曲线欧拉网格,保证了问题的高效和精确的空间解算。直接强制IB方法的移动最小二乘(MLS)版本(Vanella和Balaras, 2009)用于为每个拉格朗日标记构建IB核。此外,MLS方法还用于构造计算域边界附近拉格朗日点的单侧核函数。讨论了曲线网格上高效IB仿真的挑战,并在MLS框架内提出了解决方案。Wood和Breuer(2025)对预测结果进行了详细分析,并与实验数据进行了验证,从而深入了解了新设计在产生受控阵风方面的有效性。
A dynamic immersed boundary method for simulating an adaptive nozzle generating discrete wind gusts
The recently developed wind gust generator, the adaptive nozzle (Wood and Breuer, 2025) , features a nozzle with a fully rotatable upper contour, enabling a smooth gust generation with low unwanted flow disturbances. While preserving the underlying gust-generation principle of its predecessor, the new design significantly reduces pressure losses caused by flow blockage and preserves the original horizontal trajectory of the flow along the streamwise direction. While experiments have validated the improved design, a comprehensive numerical analysis is crucial to resolve the three-dimensional flow fields across the entire computational domain. This shall also facilitate capturing the resulting transient aerodynamic loads on a wind tunnel specimen — quantities difficult to measure experimentally. To accurately capture the complex flow dynamics, high-fidelity large-eddy simulations are conducted, modeling the nozzle’s upper contour as a dynamic immersed boundary (IB). A curvilinear Eulerian grid is employed to ensure both efficient and precise spatial resolution of the problem. The moving least-squares (MLS) version of the direct forcing IB approach (Vanella and Balaras, 2009) is used to construct an IB kernel for each Lagrangian marker. Additionally, the MLS approach is also applied to construct one-sided kernel functions for Lagrangian points near the boundaries of the computational domain. Challenges related to the efficient IB simulation on curvilinear grids are addressed, and a solution is proposed within the MLS framework. The predicted results are analyzed in detail and validated against the experimental data by Wood and Breuer (2025) , providing insights into the effectiveness of the new design in generating controlled wind gusts.
期刊介绍:
Computers & Fluids is multidisciplinary. The term ''fluid'' is interpreted in the broadest sense. Hydro- and aerodynamics, high-speed and physical gas dynamics, turbulence and flow stability, multiphase flow, rheology, tribology and fluid-structure interaction are all of interest, provided that computer technique plays a significant role in the associated studies or design methodology.