Maximization of inertial waves focusing in linear and nonlinear regimes

This study investigates the focusing of inertial waves (IW) generated by an axisymmetric torus oscillating in a rotating fluid. A full range of vertical kinetic energy propagation angles at the focal point was explored using direct numerical simulations (DNS). A systematic comparison was made between linear DNS and nonlinear DNS. It was found that there is an optimal angle that maximizes energy transfer from the torus to the focal zone. In addition, triadic IW resonances were identified as a source of turbulence and a large central vertical vortex was also identified in agreement with the theory of Davidson et al. (2006).