在表征流体动力问题的基本方程的基础上，推导了系列产品在涉及流体动力问题时所应遵循的四个设计准测，以保证系列产品在动力、运动、空间结构上的相似性。并以一种粉磨设备为例，利用推导的设计准则给出有关部件的结构设计依据。 On the basis of characterizing the basic equations of fluid dynamics, four design criteria of the series of products to be followed when dealing with hydrodynamic problems are derived to ensure the similarities in the dynamics, motions and spatial structures of the series of products. Taking a grinding equipment as an example, the structural design basis of the relevant components is given by using the derived design criteria.