随着高速列车运行速度的不断提升,空气动力学特性对列车性能的影响日益显著。风洞试验与数值仿真是研究高速列车气动性能的重要手段,但现有研究对网格设计在验证过程中的关键作用缺乏系统性探讨。本文以国内某型高速列车为研究对象,基于...随着高速列车运行速度的不断提升,空气动力学特性对列车性能的影响日益显著。风洞试验与数值仿真是研究高速列车气动性能的重要手段,但现有研究对网格设计在验证过程中的关键作用缺乏系统性探讨。本文以国内某型高速列车为研究对象,基于STAR CCM+流体仿真软件,结合风洞试验数据,分析了不同网格设计对气动阻力计算结果的影响。通过对比棱柱层网格与切割体网格的设计方案,发现车身棱柱层至少需6层以准确捕捉边界层流动,转向架区域棱柱层设计需与车身网格协调过渡,而车头、车尾加密块对阻力计算结果影响较小。研究结果表明,合理的网格设计可将仿真结果与试验数据的相对误差控制在5%左右,验证了网格优化对提高数值模拟精度的重要性。本研究为高速列车空气动力学仿真中的网格设计提供了参考依据。With the continuous increase in the operating speed of high-speed trains, the impact of aerodynamic characteristics on train performance is becoming increasingly significant. Wind tunnel testing and numerical simulation are important means of studying the aerodynamic performance of high-speed trains, but existing research lacks systematic exploration of the key role of grid design in the verification process. This article takes a certain type of high-speed train in China as the research object, and based on STAR CCM+ fluid simulation software, combined with wind tunnel test data, analyzes the influence of different grid designs on the calculation results of aerodynamic resistance. By comparing the design schemes of prism layer mesh and cutting body mesh, it was found that the body prism layer needs at least 6 layers to accurately capture the boundary layer flow, and the prism layer design in the bogie area needs to coordinate and transition with the body mesh. However, adding dense blocks at the front and rear of the vehicle has a relatively small impact on the resistance calculation results. The research results indicate that a reasonable grid design can control the relative error between simulation results and experimental data about 5%, verifying the importance of grid optimization in improving numerical simulation accuracy. This study provides a reference for grid design in aerodynamic simulation of high-speed trains.展开更多
Meshes in the sheet of Laminated Object Manufacturing (LOM) are now designedwith the same size, and the length of mesh lines may be as several times as the outline length.The method of variablesize meshes is advanced ...Meshes in the sheet of Laminated Object Manufacturing (LOM) are now designedwith the same size, and the length of mesh lines may be as several times as the outline length.The method of variablesize meshes is advanced in this paper. Meshes in a sheet are designed ac-cording to the difficulty of removing the waste in or out of the outlines. The CAD model may bedivided into several segments in Z direction with different mesh sizes. The length of mesh lineswould be largely decreased and the manufacturing efficiency would be improved.展开更多
文摘随着高速列车运行速度的不断提升,空气动力学特性对列车性能的影响日益显著。风洞试验与数值仿真是研究高速列车气动性能的重要手段,但现有研究对网格设计在验证过程中的关键作用缺乏系统性探讨。本文以国内某型高速列车为研究对象,基于STAR CCM+流体仿真软件,结合风洞试验数据,分析了不同网格设计对气动阻力计算结果的影响。通过对比棱柱层网格与切割体网格的设计方案,发现车身棱柱层至少需6层以准确捕捉边界层流动,转向架区域棱柱层设计需与车身网格协调过渡,而车头、车尾加密块对阻力计算结果影响较小。研究结果表明,合理的网格设计可将仿真结果与试验数据的相对误差控制在5%左右,验证了网格优化对提高数值模拟精度的重要性。本研究为高速列车空气动力学仿真中的网格设计提供了参考依据。With the continuous increase in the operating speed of high-speed trains, the impact of aerodynamic characteristics on train performance is becoming increasingly significant. Wind tunnel testing and numerical simulation are important means of studying the aerodynamic performance of high-speed trains, but existing research lacks systematic exploration of the key role of grid design in the verification process. This article takes a certain type of high-speed train in China as the research object, and based on STAR CCM+ fluid simulation software, combined with wind tunnel test data, analyzes the influence of different grid designs on the calculation results of aerodynamic resistance. By comparing the design schemes of prism layer mesh and cutting body mesh, it was found that the body prism layer needs at least 6 layers to accurately capture the boundary layer flow, and the prism layer design in the bogie area needs to coordinate and transition with the body mesh. However, adding dense blocks at the front and rear of the vehicle has a relatively small impact on the resistance calculation results. The research results indicate that a reasonable grid design can control the relative error between simulation results and experimental data about 5%, verifying the importance of grid optimization in improving numerical simulation accuracy. This study provides a reference for grid design in aerodynamic simulation of high-speed trains.
文摘Meshes in the sheet of Laminated Object Manufacturing (LOM) are now designedwith the same size, and the length of mesh lines may be as several times as the outline length.The method of variablesize meshes is advanced in this paper. Meshes in a sheet are designed ac-cording to the difficulty of removing the waste in or out of the outlines. The CAD model may bedivided into several segments in Z direction with different mesh sizes. The length of mesh lineswould be largely decreased and the manufacturing efficiency would be improved.
