Vorticity Generation Mechanisms and Correct Boundary Conditions for Transverse Jet Simulation

A three-dimensional vortex element method is developed to simulate the flow field of an incompressible transverse jet at high Reynolds number --- in particular, to explore the response of large-scale vortical structures in the jet to actuation. Vorticity produced in the channel wall boundary layer interacts with the jet flow at the nozzle exit, producing both axial and azimuthal perturbations to the primary azimuthal jet vorticity. We derive vorticity boundary conditions that incorporate this interaction, providing a general framework for modeling vorticity associated with actuation. A comparison of centerplane trajectories for unforced transverse jets illustrates the effect of vorticity boundary conditions on the jet near field