Vorticity generation by asymmetric energy deposition in a gaseous medium

This paper develops in detail the theory of vorticity generation by asymmetries which are presented when a cylindrical pulse of energy is deposited in a gaseous medium. We identify three classes of asymmetry which may occur separately or in combination, depending on the experiment being analyzed. We also introduce a convenient representation of the flow field in terms of one or more vortex filament pairs having identical strengths. The equations which give the vortex filament strength for the various asymmetry classes differ only in the value of a form factor, which contains information regarding geometric effects and hydrodynamic interactions. The form factor, however, depends only weakly on the profile of the density distribution of the medium prior to energy deposition. Finally we verify and calibrate the analytic results by providing data from accurate two-dimensional simulations of several cases. The analytical and numerical calculations agree closely for all examples considered.