two different points of view in analyzing problems in mechanics The Eulerian view(欧拉观点 and the lagrangian view(拉格朗日观点) flow classification Stream line(流线) Pathline(迹线)& Flowfield 〔流场)流线方程,计算流谱 Surface force(表面力) and body force(质量力,体积力)* Two different points of view in analyzing problems in mechanics The Eulerian view (欧拉观点)and the Lagrangian view （拉格朗日观点） * Flow classification * Streamline(流线),Pathline(迹线) & Flowfield (流场) 流线方程,计算流谱 * Surface force(表面力) and body force（质量力，体积力）