利用导流装置降低大后壁车辆气动阻力的实验研究(Ⅰ)

利用1/16缩比的公共汽车模型及两种类型的导流装置，在一带有可移动地面和边界层吸收装置的Eiffel型风洞中进行了在车辆后端面的上下边和侧边分别安装导流装置时车辆后部尾流区的压强恢复及气动阻力降低的实验。应用边界层分离理论比较详细地分析了安装导流装置的车辆后部尾流区的流动机理，综合分析评价了车辆表面与导流装置间的缝隙在空气引流及车辆气动阻力的降低中的作用，为新型车辆的设计和改造提供有利依据。     

Computational modeling of magnetic fields in solar active regions

The magnetic field plays an important role in various solar activities. This paper reviews techniques for computational modeling of magnetic fields in solar active regions. The input data are photospheric magnetic fields supplied by magnetograph observations. The field above the photosphere is computed by assuming an equation for the magnetic field. Three classes of magnetic fields, namely current-free fields, constant- force-free fields, and general force-free fields are considered. Their physical/mathematical significances and computational procedures are systematically presented.