Turbulence of vertical round buoyant jets in a cross flow

2004 ◽  
pp. 1167-1174 ◽  
Author(s):  
M Meftah ◽  
A Petrillo ◽  
P Davies ◽  
D Malcangio ◽  
M Mossa
Keyword(s):  
Cross Flow ◽  
Buoyant Jets

Multiple‐port buoyant jets in density stratified cross flow

1990 ◽  
Vol 13 (5) ◽  
pp. 543-553
Author(s):  
Robert R. Hwang ◽  
Yin‐Fan Pon ◽  
Wen‐Chang Yang
Keyword(s):  
Cross Flow ◽  
Buoyant Jets

Effect of Ambient Stratification on Buoyant Jets in Cross-Flow

1995 ◽  
Vol 121 (8) ◽  
pp. 865-872 ◽  
Author(s):  
Robert R. Hwang ◽  
T. P. Chiang ◽  
W. C. Yang
Keyword(s):  
Cross Flow ◽  
Buoyant Jets

Assessment of Cooling Tower Discharge Recirculation and Dispersion Using CFD Techniques

2015 ◽  
Author(s):  
S. Pal ◽  
L. J. Peltier ◽  
A. Rizhakov ◽  
M. P. Kinzel ◽  
M. H. Elbert ◽  
...  
Keyword(s):  
Experimental Data ◽  
Cooling Tower ◽  
Cross Flow ◽  
Bluff Bodies ◽  
Cooling Towers ◽  
Design Strategies ◽  
Worst Case ◽  
Buoyant Jets ◽  
Design Values ◽  
High Reynolds

The performance of cooling towers, whether operating by themselves, or in close vicinity of other cooling towers can be adversely affected by the re-ingestion of the cooling tower discharge into the tower intakes. The recirculation of the discharge from a wet cooling tower raises the wet bulb temperature of the air entering a wet cooling tower. Current design strategies, often account for this discharge re-ingestion issue, through a conservative adjustment to the far field ambient wet bulb temperature to calculate the actual intake wet bulb temperature. Critical applications, such as those related to nuclear safety applications where there is concern about cooling tower performance, may require more accurate and comprehensive assessment of the recirculation and dispersion of cooling tower discharge. Gaussian plume models alone are of limited use when dealing with discharges in the vicinity of large structures. This paper discusses the use of a computational fluid dynamics approach to evaluate worst case discharge recirculation effects in cooling towers. The bounding design values of tower intake wet bulb temperature increase due to recirculation (ingestion of tower’s own discharge), and interference (ingestion of another interfering tower’s discharge), are calculated considering the various conditions of cooling tower operation, ambient temperature, humidity and wind conditions. The RANS CFD model used in the study is evaluated against published experimental data for flow over bluff bodies at high Reynolds numbers, and experimental data on buoyant jets in cross flow.

scholarly journals 2D PIV Measurement of Twin Buoyant Jets in Wavy Cross-Flow Environment

Water ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 399 ◽  
Author(s):  
Zhenshan Xu ◽  
Ebenezer Otoo ◽  
Yongping Chen ◽  
Hongwei Ding
Keyword(s):  
Current Velocity ◽  
Near Field ◽  
Velocity Ratio ◽  
Cross Flow ◽  
Buoyant Jets ◽  
Flow Environment ◽  
Piv Measurement ◽  
Jet Trajectory ◽  
Twin Jets ◽  
Effluent Discharge

The multiport diffuser effluent discharge facilities constructed beneath the coastal waters were simplified in the laboratory as twin buoyant jets in a wavy cross-flow environment. The near-field flow structure of twin jets was studied by series of experiments conducted in a physical wave–current flume. The particle image velocimetry (PIV) system was used to measure the velocity field of the jets in various cross-flow-only and wavy cross-flow environments. By means of flow visualization, the distinctive “effluent cloud” (EC) phenomenon was clearly observed and the jet penetration height was found to be notably increased compared with that of cross-flow-only environment at the downstream position. It was found that the wave-to-current velocity ratio Rwc is a very important parameter for effluent discharge. A new characteristic velocity uch and the corresponding characteristic length scale lmb for twin buoyant jets in the wavy cross-flow environment were defined. Using curve-fitting, a new equation to estimate the effects of the jet-to-current velocity ratio (Rjc), wave-to-current velocity ratio (Rwc) and Strouhal number (St) on the jet trajectory were derived to enhance understanding the physical processes underpinning the rise and the dilution of buoyant jets, which is critical to the design of discharge facilities.

An Experimental Investigation of Merging Buoyant Jets in a Crossflow

1982 ◽  
Vol 104 (2) ◽  
pp. 236-240 ◽  
Author(s):  
M. Gregoric ◽  
L. R. Davis ◽  
D. J. Bushnell
Keyword(s):  
Cross Sections ◽  
Salt Water ◽  
Cross Flow ◽  
Vortex Sheet ◽  
Buoyant Jets ◽  
Inverted Position ◽  
Head Tank ◽  
Discharge Velocity ◽  
Multiple Jets ◽  
Crossflow Velocity

Merging buoyant jets discharged in a crossflow were investigated experimentally using a unique visualization technique. Salt water jets were discharged from a constant head tank while being towed in an inverted position at desired rates through stagnant receiving water. Visualization of the jet cross section was produced by using fluorescent dye and a vertical slit light source. The results were photographed as a sequence of instantaneous cross sections taken by a motor-driven camera. Maximum heights, widths, and the vertical cross sections of the deflected jets were determined for different ratios of crossflow velocity to discharge velocity, number of discharge jets and discharge nozzle line orientation. Horseshoe shaped cross sections were observed in the cases of a single jet and multiple jets where the crossflow velocity was parallel to the line of discharge ports, but the horseshoe pattern was not clear when the cross flow was perpendicular to the line of multiple jets. The wake behind the multiple jets in the crossflow exhibited a distinct trailing vortex sheet.

scholarly journals Buoyant Jets in Cross-Flows: Review, Developments, and Applications

2021 ◽  
Vol 9 (1) ◽  
pp. 61
Author(s):  
Mostafa Taherian ◽  
Abdolmajid Mohammadian
Keyword(s):  
Film Cooling ◽  
Cross Flow ◽  
Vortex Pair ◽  
Design Guidelines ◽  
Future Research ◽  
Marine Biota ◽  
Buoyant Jet ◽  
Buoyant Jets ◽  
Practical Applications ◽  
Accurate Design

Significant environmental effects from the use of marine outfall discharges have led to increased efforts by both regulatory bodies and research groups to minimize the negative impacts of discharges on the receiving water bodies. Understanding the characteristics of discharges under conditions representative of marine environments can enhance the management of discharges and mitigate the adverse impacts to marine biota. Thus, special attention should be given to ambient cross-flow effects on the mixing behaviors of jet discharges. A buoyant jet in cross-flow has different practical applications such as film cooling and dilution, and provide a higher mixing capability in comparison with free jets or discharges into stationary environments. The main reason for this is believed to be the existence of various complicated vortical structures including a counter-rotating vortex pair as the jet expands downstream. Although tremendous research efforts have been devoted to buoyant jets issuing into cross-flows over the past five decades, the mixing process of an effluent at the discharge point is not yet well understood because of the highly complex fluid interactions and dispersion patterns involved. Therefore, there is a need for a deeper understanding of buoyant jets in cross-flows in order to obtain better predictive methods and more accurate design guidelines. The main aims of this study were (i) to establish the background behind the subject of buoyant jets in cross-flows including the flow structures resulting from the interaction of jets and cross-flows and the impacts of current on mixing and transport behavior; (ii) to present a summary of relevant experimental and numerical research efforts; and finally, (iii) to identify and discuss research gaps and future research directions.

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