Study of the role of differential diffusion and equation of state on the features of stably stratified turbulent channel flow using direct numerical simulations

Stably stratified turbulent flows are observed in many systems, ranging from engineering applications to environmental flows. The density variation in such flows, particularly that observed in water bodies depends on temperature and salinity (salt content) through an equation of state (EoS). The molecular diffusion of the temperature and salinity in such flows differ substantially, which leads to the presence of a differential diffusion phenomenon. This furthers the complexity of stratified turbulence, where the density stratification is known to alter the dynamics of turbulence. In this study, results from direct numerical simulations of stably stratified turbulent channel flow under moderate levels of differential diffusion and two types of EoS are examined in terms of instantaneous, statistical, spectral, and modal features of the flow field. The study shows that the effects of differential diffusion are dominant compared to the type of EoS on the spatio-temporal dynamics and statistics of the flow field.

Grantor dc:publisher

University of Tennessee at Chattanooga

Author dc:creator

• Thompson, Steven

Contributors dc:contributor

• Ranjan, Reetesh
• Sreenivas, Kidambi; Margraves, Charles
• College of Engineering and Computer Science

• Stratified flow
• Equations of state

Licence

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language

English, eng

Repository record dc:identifier

https://scholar.utc.edu/theses/961

OAI identifier oai:identifier

oai:scholar.utc.edu:theses-2146