Fundamental TheoremsAn overview of the integral theorems that connect local differential quantities with global integral quantities in fluid dynamics.

Basic MathematicsEinstein Summation Convention (爱因斯坦求和约定)For vector and tensor equations, the longest but clearest notation is the Cartesian one. If the equation contains several similar terms which can be summed up , this notation can be abbreviated by applying the Einsteins summation convention. 对于向量和张量方程，最清晰且最长的表示方法就是笛卡尔表示。但是，如果这些方程中的某些项重复出现，则可以用 Einstein summation convention 来简化方程。