Published online by Cambridge University Press: 22 December 2017
Building on work of Prandtl and Alexander, we study logarithmic vortex spiral solutions of the two-dimensional incompressible Euler equations. We consider multi-branched spirals that are not symmetric, including mixtures of sheets and continuum vorticity. We find that non-trivial solutions allow only sheets, that there is a large variety of such solutions, but that only the Alexander spirals with three or more symmetric branches appear to yield convergent Biot–Savart integral.
The authors' research was partially supported by the National Science Foundation under Grant NSF DMS-1054115 and by Taiwan MOST grant 105-2115-M-001-007-MY3.