Written in English
Thesis (Ph.D.), Dept. of Physics, University of Toronto
|Contributions||Peltier, W. R. (supervisor)|
|The Physical Object|
|Number of Pages||310|
In particular, DNS and RDT of decaying, homogeneous, stably-stratified turbulence are used to determine the mixing efficiency as a function of the initial turbulence Richardson number Rit0=(NL0/u0. Time-dependent, non-monotonic mixing in stratified turbulent shear flows: implications for oceanographic estimates of buoyancy flux - Volume - A. Mashayek, C. P. Caulfield, W. R. Peltier Book chapters will be unavailable on Saturday 24th August between 8ampm by: In fluid dynamics, the process of a laminar flow becoming turbulent is known as laminar–turbulent main parameter characterizing transition is the Reynolds number.. Transition is often described as a process proceeding through a series of stages. "Transitional flow" can refer to transition in either direction, that is laminar–turbulent transitional or turbulent–laminar. Rb must be above some value, typically taken to be 25 - 30, for stratified turbulence to be in interesting. If the flow is strongly stratified as it is in many geophysical flows, at least billion grid points are needed for a 3D simulation at high enough Rb. Kelvin-Helmholtz Instability Several mechanisms cause turbulence in stratified flows.
Our objective in this study is to study inhomogeneous stratified shear flows using large eddy simulation; stratified pressure-gradient-driven channel flow was selected. The flows can be separated into three regimes: buoyancy affected, buoyancy controlled, and buoyancy dominated flows. The regime boundaries are defined by Richardson and Reynolds numbers based on the friction by: Purchase Transition and Turbulence - 1st Edition. Print Book & E-Book. ISBN , The origin and the structure of turbulence in stably stratified media are investigated through theoretical reasoning and laboratory experiments. The limitations of existing stability theories of parallel horizontal shear flows and the resulting critical gradient Richardson number are by: 5. Subcritical Transition to Turbulence in Planar Shear Flows S. A. Orszag and A. T. Patera 1 Introduction Oiere is a large discrepancy between the results of parallel flow linear stability theory and experimental observations of transition in plane channel by:
There have also been some studies of the turbulent mixing coefficient in stably stratified flows by atmospheric scientists, starting with Lilly et al. (), who suggested a value of corresponding to the upper limit on the flux Richardson number of Cited by: 4. 4. Phase coexistence in thermodynamics and occurrence of turbulent spots in transition flows. Hopefully the previous developments have shown that one has to use ideas beyond chaos theory in its usual meaning to understand the transition to turbulence in parallel flows (and so in systems with many degrees of freedom).Cited by: The influence of stable stratification in boundary-forced turbulent flows is studied in the prototypical case of channel flow using large eddy simulations. As stratification increases, active wall-bounded turbulence with reduced vertical transport coexists with internal wave activity in the core of the : Vincenzo Armenio, Sutanu Sarkar. Book Description. Addressing classical material as well as new perspectives, Instabilities of Flows and Transition to Turbulence presents a concise, up-to-date treatment of theory and applications of viscous flow instability. It covers materials from classical instability to contemporary research areas including bluff body flow instability, mixed convection flows, and application areas of.