Asymmetric stratified wakes

Previous studies have suggested that all stratified wakes arrive at some universal state where the information about the wake generator is lost. However, there is scant evidence on whether wakes seeded with some specific asymmetric initial conditions can retain information about their origin through late stages of their evolution. In particular, there is interest in the wake of an inclined spheroid, as the asymmetry from the combination of drag wake and separation vortices presents a special opportunity for unique pattern generation. Here, a 6:1 prolate spheroid is towed in a refractive-index-matched salt-stratified fluid with varying incidence angle, θ = {0,10,20}°, Reynolds number, Re_D = {0.5, 1, 2} × 10⁴ and Froude number, Fr = {16, 32, 64, ∞}. Both stereo-PIV (2D3C) of two orthogonal planes and tomo-PIV (3D3C) are used to quantify the development of 3D flow structures in the near-wake.