Theoretical Study of a Laminar Jet in a Double-Diffusion Environment

1995 ◽  
Vol 117 (3) ◽  
pp. 341-346 ◽  
Author(s):  
M. Priven ◽  
J. F. Atkinson ◽  
G. A. Bemporad ◽  
H. Rubin
Keyword(s):  
Theoretical Study ◽  
Double Diffusion ◽  
Two Dimensional ◽  
Local Reference Frame ◽  
Field Development ◽  
Laminar Jet ◽  
Fluid Layers ◽  
Diffusion Effects ◽  
Local Reference ◽  
Layer Development

The flow field development associated with the injection of negatively, neutrally, and positively buoyant fluid layers into a stratified environment was analyzed in this study. The analysis considered two-dimensional (horizontal slot) fluid injection under laminar conditions in either temperature-stratified, salinity-stratified or double-diffusive stratified environments. The major features characterizing the buoyant layer development were identified. A numerical model, which integrates in a local reference frame the equations governing mass, momentum, heat and salinity fluxes, was developed. The model was used to examine the characteristic flow patterns for the two-dimensional buoyant discharges of interest in this study. It was also possible to show that double-diffusion effects may significantly influence the development of initially neutral fluid layers and cause a certain vertical deviation.

Experimental Study of a Laminar Jet in a Double-Diffusion Environment

1995 ◽  
Vol 117 (3) ◽  
pp. 347-354 ◽  
Author(s):  
M. Priven ◽  
G. A. Bemporad ◽  
J. Atkinson ◽  
H. Rubin
Keyword(s):  
Fluid Layer ◽  
Double Diffusion ◽  
Vertical Displacement ◽  
Laminar Jet ◽  
Density Distributions ◽  
Fluid Layers ◽  
Laboratory Flume ◽  
Basic Features ◽  
Negatively Buoyant ◽  
Good Agreement

An experimental analysis of the flow development caused by the simultaneous injection and withdrawal of a buoyant fluid layer with low Reynolds number in a double-diffusion environment is presented. The injection of positively, neutrally, and negatively buoyant fluid layers was simulated in the experimental setup. Innovative procedures were developed to efficiently create the desired density distributions in the laboratory flume. Results presented in this paper concern the injection of fluid into environments stratified by temperature, salinity or both. Basic features of the flow patterns are described, in particular, intrusion rate, effect on ambient stratification and vertical displacement. The experimental data on the fluid vertical displacement were compared with results from a numerical model and good agreement was found.

Plane turbulent jets in a bounded fluid layer

1992 ◽  
Vol 241 ◽  
pp. 587-614 ◽  
Author(s):  
T. Dracos ◽  
M. Giger ◽  
G. H. Jirka
Keyword(s):  
Experimental Investigation ◽  
Cross Section ◽  
Fluid Layer ◽  
Three Dimensional ◽  
Turbulent Jets ◽  
Two Dimensional ◽  
Vortical Structures ◽  
Secondary Currents ◽  
Fluid Layers ◽  
Bounding Surfaces

An experimental investigation of plane turbulent jets in bounded fluid layers is presented. The development of the jet is regular up to a distance from the orifice of approximately twice the depth of the fluid layer. From there on to a distance of about ten times the depth, the flow is dominated by secondary currents. The velocity distribution over a cross-section of the jet becomes three-dimensional and the jet undergoes a constriction in the midplane and a widening near the bounding surfaces. Beyond a distance of approximately ten times the depth of the bounded fluid layer the secondary currents disappear and the jet starts to meander around its centreplane. Large vortical structures develop with axes perpendicular to the bounding surfaces of the fluid layer. With increasing distance the size of these structures increases by pairing. These features of the jet are associated with the development of quasi two-dimensional turbulence. It is shown that the secondary currents and the meandering do not significantly affect the spreading of the jet. The quasi-two-dimensional turbulence, however, developing in the meandering jet, significantly influences the mixing of entrained fluid.

THEORETICAL FOUNDATIONS FOR THE CREATION OF A «FRAME» GEOTECHNOLO-GY FOR UNDERGROUND DEVELOPMENT OF SUBSURFACE RESOURCES

2021 ◽  
Vol 4 (1) ◽  
pp. 295-304
Author(s):  
Yu.P. Galchenko ◽  
◽  
V.A. Eremenko ◽  
Keyword(s):  
Stress Field ◽  
Theoretical Study ◽  
Underground Mining ◽  
Field Development ◽  
Variable Volume ◽  
Technological Paradigm ◽  
External Contour ◽  
Subsurface Exploration ◽  
Dynamic Structures ◽  
Theoretical Foundations

A physical model of the process of underground ore mining is substantiated and it is shown that ensuring the geomechanical safety of subsurface development is associated with the technological capabilities of nature-like mining technologies for the reproduction of stable dy-namic structures in the lithospheric objects being worked out. A cognitive analysis of typical geotechnologies is carried out and it is shown that the modern geo-technological paradigm is based on the principles of combining in time the processes that generate a geomechanical dis-turbance in the lithosphere and the processes to overcome the consequences of this disturb-ance. The internally insoluble contradiction of this approach is revealed and it is shown that overcoming this contradiction opens up a very real prospect of creating a fundamentally new concept for the development of underground mining technologies based on the implementation of the global idea of nature-like technologies in the form of the concept of creating convergent mining technologies. With the use of the proposed and developed by prof. The Rodionov model of the lithosphere as a solid body with different-scale inhomogeneities performed a theoretical study of the features of the stress field development during the formation of inhomogeneities with variable volume and zero density and found that in this case, the conditions for the repro-duction of stable dynamic structures will be determined by processes on the external contour of inhomogeneities. This made it possible to substantiate the geophysical and geotechnological ideas of a new technological paradigm of subsurface exploration.

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