Exact analytical solution for one nonlinear variational problem of the cavitation theory

In this paper we investigate the limiting values of the lift and drag coefficients of profiles in the Helmholtz--Kirchhoff (infinite cavity) flow. The coefficients are based on the wetted arc length of profile surfaces. Namely, for a given value of the lift coefficient we find minimum and maximum values of the drag coefficient. Thereby, we determine maximum and minimum values of the lift-to-drag ratios.