Finite-time singularity in the vortex dynamics of a string

We analyze the dynamics of a perfectly flexible string with a constant leng th and a vanishing inner friction. The local angular velocity of line eleme nts in this seemingly simple mechanical system is shown to have many mathem atical and physical propel-ties in common with vorticity in the three-dimen sional incompressible Euler equation. It is demonstrated that initially smo oth vorticity fields lose their regularity within finite time in a self-sim ilar process, and that the peak vorticity grows as omega(max)similar to(T-t )(-1). [S1063-651X(99)15002-5].