Geometric parameters mainly include the clearance between rotor and stator, the spirochetal length, the threads number of the stator, etc.Furthermore, different screw serrate pumps are also studied.

• 本文考察的几何参数主要有定子转子间隙、螺旋体长度和定子螺纹头数等，此外还对不同螺纹齿形的泵进行了研究。