Stratified propelled wakes

Stratified Propelled Wakes

A comparative study of self-propelled and towed wakes in a stratified fluid

Direct numerical simulations (DNS) of axisymmetric wakes with canonical towed and self-propelled velocity profiles are performed at Re=50 000 on a grid with approximately 2 billion grid points. The present study focuses on a comparison between towed and self-propelled wakes and on the elucidation of buoyancy effects. The development of the wake is characterized by the evolution of maxima, area ...

Three-dimensional Wakes in Linearly Stratified Liquids

THREE-DIMENSIONAL WAKES IN LINEARLY STRATIFIED LIQUIDS by Philip J. Stockhausen, Charles B. Clark Submitted to the Department of Civil Engineering on May 26, 1966, in partial fulfillment of the requirements for the degree of Master of Science. The wake and the zone of turbulently mixed fluid behind a threedimensional body in a liquid with a linear density gradient were studied. The objective of...

Self-preservation in stratified momentum wakes

A general model is described for drag wakes in a linearly stratified fluid, based on the selfpreservation of the flow. It is assumed that the buoyancy-controlled self-similar wake expands in the horizontal direction due to turbulent diffusion and in the vertical direction due to viscous diffusion. The mean characteristics of the wake (height, width and velocity defect) are analytically derived ...

Reynolds number effects in stratified turbulent wakes

We report large-eddy simulations of the turbulent wake of a towed-sphere of diameter D at speed U in a linearly stratified Boussinesq fluid with buoyancy frequency N . These simulations are performed using a spectral-multidomain-penalty-method-based incompressible Navier-Stokes solver for Re ≡ UD/ν ∈ {5 × 10, 10, 4 × 10} and Fr ≡ 2U/(ND) ∈ {4, 16, 64}. Increasingly richer turbulent fine structu...