A two-dimensional（2-D） incompressible plane jet is investigated using the lattice Boltzmann method（LBM） for low Reynolds numbers of 42 and 65 based on the jet-exit-width and the maximum jet-exit-velocity. The resu...A two-dimensional（2-D） incompressible plane jet is investigated using the lattice Boltzmann method（LBM） for low Reynolds numbers of 42 and 65 based on the jet-exit-width and the maximum jet-exit-velocity. The results show that the mean centerline velocity decays as x-1/3 and the jet spreads as x2/3 in the self-similar region, which are consistent with the theoretical predictions and the experimental data. The time histories and PSD analyses of the instantaneous centerline velocities indicate the periodic behavior and the interaction between periodic components of velocities should not be neglected in the far field region, although it is invisible in the near field region.展开更多
为了更深入分析大到暴雪天气过程的热力与动力特征、中尺度系统结构及大到暴雪发生的物理机制,利用1951-2013年的地面观测、MICAPS数值预报产品、NCEP、历史天气图等资料,完成内蒙古东南部大到暴雪天气过程的天气学分型及“分型配料法...为了更深入分析大到暴雪天气过程的热力与动力特征、中尺度系统结构及大到暴雪发生的物理机制,利用1951-2013年的地面观测、MICAPS数值预报产品、NCEP、历史天气图等资料,完成内蒙古东南部大到暴雪天气过程的天气学分型及“分型配料法”、降水相态、相似预报;建立25个站点的历史个例库,可进行显示、查询、增加、修改及删除;系统基于新一代卫星接收系统(CMACAST),经过MDS处理后,建立数值预报产品插值库,显示站点的预报时次曲线图。系统采用C/S架构和模块化设计,使用VS2008.NET进行研发并使用SQL Server 2008建立数据库。所有数据实验结果表明,该系统统一出入口、界面友好、系统功能完整、可移植性强,4年来运行稳定。该系统可为预报员更好地对大到暴雪的分析、分型及大到暴雪落区、降水相态、相似预报及短临预报提供快捷方便的数据和技术支撑。展开更多
基金Supported by the National Nature Science Foundation of China(10472046)the Scientific Innova-tion Research of College Graduate in Jiangsu Province(CX08B-035Z)the Innovation and Excellence Foundation of Doctoral Dissertation of Nanjing University of Aeronautics and Astronautics(BCXJ08-01)~~
文摘A two-dimensional（2-D） incompressible plane jet is investigated using the lattice Boltzmann method（LBM） for low Reynolds numbers of 42 and 65 based on the jet-exit-width and the maximum jet-exit-velocity. The results show that the mean centerline velocity decays as x-1/3 and the jet spreads as x2/3 in the self-similar region, which are consistent with the theoretical predictions and the experimental data. The time histories and PSD analyses of the instantaneous centerline velocities indicate the periodic behavior and the interaction between periodic components of velocities should not be neglected in the far field region, although it is invisible in the near field region.
文摘为了更深入分析大到暴雪天气过程的热力与动力特征、中尺度系统结构及大到暴雪发生的物理机制,利用1951-2013年的地面观测、MICAPS数值预报产品、NCEP、历史天气图等资料,完成内蒙古东南部大到暴雪天气过程的天气学分型及“分型配料法”、降水相态、相似预报;建立25个站点的历史个例库,可进行显示、查询、增加、修改及删除;系统基于新一代卫星接收系统(CMACAST),经过MDS处理后,建立数值预报产品插值库,显示站点的预报时次曲线图。系统采用C/S架构和模块化设计,使用VS2008.NET进行研发并使用SQL Server 2008建立数据库。所有数据实验结果表明,该系统统一出入口、界面友好、系统功能完整、可移植性强,4年来运行稳定。该系统可为预报员更好地对大到暴雪的分析、分型及大到暴雪落区、降水相态、相似预报及短临预报提供快捷方便的数据和技术支撑。
