The purpose of this work is to prove existence of a weak solution of the two
dimensional incompressible Euler equations on a noncylindrical domain
consisting of a smooth, bounded, connected and simply connected domain
undergoing a prescribed motion. We prove existence of a weak solution for
initial vorticity in Lp, for p>1. This work complements a similar result
by C. He and L. Hsiao, who proved existence assuming that the flow velocity is
tangent to the moving boundary, see [JDE v. 163 (2000) 265--291].Comment: 16 page