Translated from Gidrotekhnicheskoe Stroitel 'stvo, No. 2, February 2015, pp. 32 -44. It is demonstrated that for kinematically similar potential flows of an ideal liquid, the ratio of the velocities is inversely proportional to the ratio of the areas of the corresponding equipotential surfaces S 1 /S 2 = K v , and directly proportional to the ratio of the flows. In that case when the flow rates of two flows are equal, the function of the velocity potential and the velocity of one flow can be expressed in terms of these characteristics multiplied by the dimensionless coefficient K v -the velocity correction of the other flow. Using the velocity correction K v , the flow caused by a cylinder flow of finite length, which is placed on an impervious cylinder in an infinite space filled with an ideal liquid is investigated in a cylindrical coordinate system. Analytical relationships are derived for the equipotential surfaces, and the flow and velocity surfaces; examples of the analysis are cited.If kinematic similitude is fulfilled for potential flows of an ideal incompressible liquid, the ratio of the velocities of these flows at corresponding points of the equipotential surfaces is inversely proportional to the ratio of the areas of these surfaces, and directly proportional to the ratio of the flow rates of liquid passing over them. In the cylindrical coordinate system (r, z, È), this is written as V V V V V V V V q S q S r r z z 1 2 1 2 1 2 1 2 1 2 2 1 = = = = avg avg (1) or V q S q S V 2 2 1 1 2 1 = ; V q S q S V r r 2 2 1 1 2 1 = ; V q S q S V z z 2 2 1 1 2 1 = ,where V r and V z are the radial and vertical velocity components, V avg are the average velocities on the equipotential surfaces, q 1 and q 2 are the flow rates of the first and second flows, respectively, and S 1 and S 2 are the areas of the corresponding equipotential surfaces of the first and second flows. If the flow rates q of the flows under consideration are similar, (2) and the function of the velocity potential Ö 2 of the second flow is expressed in terms of the function of the velocity potential Ö 1 of the first flow aswhere K v = S 1 /S 2 is a coefficient that can be called the "velocity correction." The coefficient K v is constant for points falling on the corresponding equipotential surfaces, and varies on transition from some corresponding surfaces to others.As an example of use of the velocity correction for analysis of kinematic characteristics of one of the potential flows with respect to the velocity field of the other flow, let us examine a spatial point source and plane source.For the spatial source, the function of the velocity potential Ö sp and the velocity components are expressed by the following relationships [1]:where R rR zR = + 2 2 ; and q is the flow rate of the source in m 3 /sec. The streamlines are beams that emerge from the source, while the equipotential surfaces are spheres of radius R (Fig. 1a).