流体拓扑优化是一项突破性技术,在航空航天、汽车、电子芯片等领域均有广泛的应用前景,然而其所设计出的复杂结构难以通过传统制造技术加工成型等因素制约了它的推广应用。增材制造(3D打印)技术的发展为进一步拓展流体拓扑优化的应用和...流体拓扑优化是一项突破性技术,在航空航天、汽车、电子芯片等领域均有广泛的应用前景,然而其所设计出的复杂结构难以通过传统制造技术加工成型等因素制约了它的推广应用。增材制造(3D打印)技术的发展为进一步拓展流体拓扑优化的应用和研究提供了有效途径,对实现相关工业装备的结构轻量化、动力学优化、安全性优化以及性能提升,落实国家“节能降耗、碳达峰碳中和”战略具有重要意义。借助文献计量工具VOSviewer对Web of Science数据库中流体拓扑优化相关文献进行了梳理和总结,全面系统阐述了流体拓扑优化的理论体系、求解方法、优化方法以及工程应用,并对相关问题进行了探讨。首先,与固体拓扑优化相比,流体拓扑优化涉及领域更广、流态特征更多样、数学模型更复杂,因而求解更困难、计算时间更长、计算资源需求更大,这是制约流体拓扑优化工程应用的主要因素。其次,较系统阐述了流体拓扑优化的3个环节和关键技术:拓扑设计变量表述方法、CFD模型及求解方法、拓扑优化模型及求解方法,并分析了现有技术的特点和应用场景,同时,对流体拓扑优化的电子芯片热沉、飞机汽车、换热器等几个应用场景进行了简述。最后,对流体拓扑优化的发展趋势进行了预测和总结,建议进一步加大湍流、共轭传热、流-固-热耦合、流-固-热-质耦合等方面的多学科拓扑优化研究;拓展基于多目标函数的拓扑优化研究;进一步加强与人工智能的深度结合,开发更加稳健成熟的智能CFD求解器、智能优化求解器以及智能流体拓扑优化软件。展开更多
The intermediate link compression characteristics of e-commerce express logistics ne tworks influence the tradition al mode of circulation of goods and economic organization,and alter the city spatial pattern.Based on...The intermediate link compression characteristics of e-commerce express logistics ne tworks influence the tradition al mode of circulation of goods and economic organization,and alter the city spatial pattern.Based on the theory of space of flows,this study adopts China Smart Logistics Network relational data to build China's e-commerce express logistics network and explore its spatial structure characteristics through social network analysis(SNA),the PageRank technique,and geospatial methods.The results are as follows:the network density is 0.9270,which is close to 1;hence,indicating that e-commerce express logistics lines between Chinese cities are nearly complete and they form a typical network structure,thereby eliminating fragmented spaces.Moreover,the average minimum number of edges is 1.1375,which indicates that the network has a small world effect and thus has a high flow efficiency of logistics elements.A significant hierarchical diffusion effect was observed in dominant flows with the highest edge weights.A diamond-structured network was formed with Shanghai,Guangzhou,Chongqing,and Beijing as the four core nodes.Other node cities with a large logistics scale and importance in the network are mainly located in the 19 city agglomerations of China,revealing the fact that the development of city agglomerations is essential for promoting the separation of experience space and changing the urban spatial pattern.This study enriches the theory of urban networks,reveals the flow laws of modern logistics elements,and encourages coordinated development of urban logistics.展开更多
文摘流体拓扑优化是一项突破性技术,在航空航天、汽车、电子芯片等领域均有广泛的应用前景,然而其所设计出的复杂结构难以通过传统制造技术加工成型等因素制约了它的推广应用。增材制造(3D打印)技术的发展为进一步拓展流体拓扑优化的应用和研究提供了有效途径,对实现相关工业装备的结构轻量化、动力学优化、安全性优化以及性能提升,落实国家“节能降耗、碳达峰碳中和”战略具有重要意义。借助文献计量工具VOSviewer对Web of Science数据库中流体拓扑优化相关文献进行了梳理和总结,全面系统阐述了流体拓扑优化的理论体系、求解方法、优化方法以及工程应用,并对相关问题进行了探讨。首先,与固体拓扑优化相比,流体拓扑优化涉及领域更广、流态特征更多样、数学模型更复杂,因而求解更困难、计算时间更长、计算资源需求更大,这是制约流体拓扑优化工程应用的主要因素。其次,较系统阐述了流体拓扑优化的3个环节和关键技术:拓扑设计变量表述方法、CFD模型及求解方法、拓扑优化模型及求解方法,并分析了现有技术的特点和应用场景,同时,对流体拓扑优化的电子芯片热沉、飞机汽车、换热器等几个应用场景进行了简述。最后,对流体拓扑优化的发展趋势进行了预测和总结,建议进一步加大湍流、共轭传热、流-固-热耦合、流-固-热-质耦合等方面的多学科拓扑优化研究;拓展基于多目标函数的拓扑优化研究;进一步加强与人工智能的深度结合,开发更加稳健成熟的智能CFD求解器、智能优化求解器以及智能流体拓扑优化软件。
基金Under the auspices of National Natural Science Foundation of China(No.42071165,41801144)GDAS’Project of Science and Technology Development(No.2023GDASZH-2023010101,2021GDASYL-20210103004)。
文摘The intermediate link compression characteristics of e-commerce express logistics ne tworks influence the tradition al mode of circulation of goods and economic organization,and alter the city spatial pattern.Based on the theory of space of flows,this study adopts China Smart Logistics Network relational data to build China's e-commerce express logistics network and explore its spatial structure characteristics through social network analysis(SNA),the PageRank technique,and geospatial methods.The results are as follows:the network density is 0.9270,which is close to 1;hence,indicating that e-commerce express logistics lines between Chinese cities are nearly complete and they form a typical network structure,thereby eliminating fragmented spaces.Moreover,the average minimum number of edges is 1.1375,which indicates that the network has a small world effect and thus has a high flow efficiency of logistics elements.A significant hierarchical diffusion effect was observed in dominant flows with the highest edge weights.A diamond-structured network was formed with Shanghai,Guangzhou,Chongqing,and Beijing as the four core nodes.Other node cities with a large logistics scale and importance in the network are mainly located in the 19 city agglomerations of China,revealing the fact that the development of city agglomerations is essential for promoting the separation of experience space and changing the urban spatial pattern.This study enriches the theory of urban networks,reveals the flow laws of modern logistics elements,and encourages coordinated development of urban logistics.
