Spatial characterization of vortical structures and internal waves in a stratified turbulent wake using proper orthogonal decomposition

摘要

Proper orthogonal decomposition (POD) has been applied to two-dimensional transects of vorticity obtained from numerical simulations of the stratified turbulent wake of a towed sphere at a Reynolds number Re=(UD)/ν=5×10~3 and Froude number Fr=2U/(ND)=4 (U and D are characteristic velocity and length scales and N is the stratification frequency). At 231 times during the interval 12