Abstract Amendment to in-circle and design streamline on circulatory circle during the design of hydrodynamic torque converter is commonly necessary. Taking the three circular arcs as an example, this paper presents the disadvantages of differential amendment method and further improves the amendment design of circular circle. The results indicates that torque converter, designed through this new method, achieves smooth changes of cross-sectional areas, reasonable distributions of flow field and can fulfill the requirements through one amendment.
