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.

Sea Water Intrusion Monitoring on the Sendangbiru of the Southern Malang Coastal Area based on Geoelectrical Resistivity Data

2021 ◽  
Vol 14 (9) ◽  
pp. 43-48
Author(s):  
Sunaryo .
Keyword(s):  
Data Acquisition ◽  
Cross Section ◽  
Seawater Intrusion ◽  
Cross Sections ◽  
Sea Water ◽  
Salt Water ◽  
Sea Water Intrusion ◽  
Electrical Sounding ◽  
Geoelectrical Resistivity ◽  
Intrusion Layer

The study was conducted with the objective to distinguish the presence of seawater intrusion layer or salt-water aquifer distribution along the data acquisition line at the locations. Data acquisition was conducted by using the Wenner-Schumberger configuration of geoelectrical resistivity. From this research, 4 lines and 4 points of vertical electrical sounding (VES) data for every line were obtained with the distance between electrode a as 10m. Based on the data processing, obtained depth up to 120m with the smallest resistivity value is 0.02Ωm and the largest is 6764.52Ωm. To make the distribution of resistivity values along the path line of the study, cross sections were made until a depth of 120m. Based on the cross-section, the low resistivity value (less than 1.5 Ωm) that interpreted as a seawater intrusion layer or salt water aquifer distribution is located at varying depths. There are intrusions for the SB1 cross section, there is an intrusion at a depth of 6m-7m as far as 10m, at a depth of 6m-8m as far as 10m for the SB2 cross section and at a depth of 22m - 26m as far as 25m for the SB3 cross section.

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

scholarly journals Investigation of Coolant Local Hydrodynamics in the Mixed Core of the VVER Reactor

2020 ◽  
Vol 63 (2) ◽  
pp. 151-162
Author(s):  
S. M. Dmitriev ◽  
A. V. Gerasimov ◽  
A. A. Dobrov ◽  
D. V. Doronkov ◽  
A. N. Pronin ◽  
...  
Keyword(s):  
Cross Sections ◽  
Experimental Studies ◽  
Reactor Core ◽  
Cross Flow ◽  
Coolant Flow ◽  
Vver Reactor ◽  
Computational Hydrodynamics ◽  
Cross Section Area ◽  
Fuel Assemblies ◽  
Flow Pressure

The article presents the results of experimental studies of the local hydrodynamics of the coolant flow in the mixed core of the VVER reactor, consisting of the TVSA-T and TVSA-T mod.2 fuel assemblies. Modeling of the flow of the coolant flow in the fuel rod bundle was carried out on an aerodynamic test stand. The research was carried out on a model of a fragment of a mixed core of a VVER reactor consisting of one TVSA-T segment and two segments of the TVSA-T.mod2. The flow pressure fields were measured with a five-channel pneumometric probe. The flow pressure field was converted to the direction and value of the coolant velocity vector according to the dependencies obtained during calibration. To obtain a detailed data of the flow, a characteristic cross-section area of the model was selected, including the space cross flow between fuel assemblies and four rows of fuel rods of each of the TVSA fuel assemblies. In the framework of this study the analysis of the spatial distribution of the projections of the velocity of the coolant flow was fulfilled that has made it possible to pinpoint regularities that are intrinsic to the coolant flowing around spacing, mixing and combined spacing grates of the TVSA. Also, the values of the transverse flow of the coolant caused by the flow along hydraulically nonidentical grates were determined and their localization in the longitudinal and cross sections of the experimental model was revealed. Besides, the effect of accumulation of hydrodynamic flow disturbances in the longitudinal and cross sections of the model caused by the staggered arrangement of hydraulically non-identical grates was determined. The results of the study of the coolant cross flow between fuel assemblies interaction, i.e. between the adjacent TVSA-T and TVSA-T mod.2 fuel assemblies were adopted for practical use in the JSC of “Afrikantov OKB Mechanical Engineering” for assessing the heat engineering reliability of VVER reactor cores; also, they were included in the database for verification of computational hydrodynamics programs (CFD codes) and for detailed cell-based calculation of the reactor core.

Introducing Film Cooling Uniformity Coefficient (CUC)

2008 ◽  
Author(s):  
Khodayar Javadi ◽  
Aliyar Javadi
Keyword(s):  
Cross Sections ◽  
Film Cooling ◽  
Cross Flow ◽  
Well Performance ◽  
Cooling Effectiveness ◽  
Film Cooling Effectiveness ◽  
Uniformity Coefficient ◽  
The Past ◽  
Single Jet ◽  
Hot Surface

A well performance film cooling implies for a high cooling effectives accompanied with a wide cooling coverage. During the past six decades, film cooling effectiveness has been well defined with a specific relation to quantify it. However, despite of numerous film cooling research, there is not an explicit method to quantify the uniformity of a coolant film spread over the hot surfaces. This work introduces a cooling uniformity coefficient (CUC) to evaluate how well a coolant film spreads over a surface being cooled. Four different cases are computationally studied. In the three cases, a single jet is injected into a hot cross flow with different jet exit shapes (i.e. square, spanwise rectangular, and streamwise rectangular). The fourth case is a novel combined triple jet (CTJ) introduced in our previous work. The cross sections of all the systems are equal to maintain the same coolant mass flow rate injection into the hot cross flow. The CUC’s of the different cases are compared with each other at two blowing ratios of 0.5 and 1.5. It is proposed that in addition to the film cooling effectiveness, the CUC is a necessary parameter to evaluate how well a coolant film is spread over a hot surface.

Paper 7. Unsteady Flow around a Slender Fish-Like Body

1972 ◽  
Vol 14 (7) ◽  
pp. 43-52 ◽  
Author(s):  
Th. Y. Wu ◽  
J. N. Newman
Keyword(s):  
Unsteady Flow ◽  
Theoretical Calculations ◽  
Cross Flow ◽  
Vortex Sheet ◽  
The Body ◽  
Dynamic Force ◽  
Cross Sectional ◽  
Vortex Sheets ◽  
Flat Fish ◽  
The Cross

This paper attempts to extend some recent theoretical calculations on the unsteady flow generated by body movements of a slender ‘flat’ fish by further including the effect of finite body thickness in the consideration for various configurations of side and caudal fins as major appendages. Based on the slender-body approximation, the cross-flow is determined for different longitudinal body sections which are characterized by a variety of cross-sectional shapes and flow conditions (such as having smooth or fin-edged body contours, with or without vortex sheets alongside the body section). The effect of body thickness is found to arise primarily from its interaction with the vortex sheet already existing in the cross-flow. New results for the transverse hydro-dynamic force acting on the body are obtained, and their physical significances are discussed.

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

Interference in a three-dimensional array of jets

2015 ◽  
Vol 26 (5) ◽  
pp. 795-819
Author(s):  
P. E. WESTWOOD ◽  
F. T. SMITH
Keyword(s):  
Cross Sections ◽  
Flow Direction ◽  
Three Dimensional ◽  
Cross Flow ◽  
Longitudinal Vortex ◽  
Cross Sectional ◽  
Dimensional Array ◽  
Unsteady Jets ◽  
The Cross ◽  
Jet Cross Sections

The theoretical investigation here of a three-dimensional array of jets of fluid (air guns) and their interference is motivated by applications to the food sorting industry especially. Three-dimensional motion without symmetry is addressed for arbitrary jet cross-sections and incident velocity profiles. Asymptotic analysis based on the comparatively long axial length scale of the configuration leads to a reduced longitudinal vortex system providing a slender flow model for the complete array response. Analytical and numerical studies, along with comparisons and asymptotic limits or checks, are presented for various cross-sectional shapes of nozzle and velocity inputs. The influences of swirl and of unsteady jets are examined. Substantial cross-flows are found to occur due to the interference. The flow solution is non-periodic in the cross-plane even if the nozzle array itself is periodic. The analysis shows that in general the bulk of the three-dimensional motion can be described simply in a cross-plane problem but the induced flow in the cross-plane is sensitively controlled by edge effects and incident conditions, a feature which applies to any of the array configurations examined. Interference readily alters the cross-flow direction and misdirects the jets. Design considerations centre on target positioning and jet swirling.

An Analysis of Deep Submerged Multiple-Port Buoyant Discharges

1977 ◽  
Vol 99 (4) ◽  
pp. 648-654 ◽  
Author(s):  
L. D. Kannberg ◽  
L. R. Davis
Keyword(s):  
Experimental Data ◽  
Experimental Study ◽  
Gradual Transition ◽  
Two Dimensional ◽  
Buoyant Jets ◽  
Multiple Jets ◽  
Buoyant Discharges

The results of an experimental study of deep submerged multiple-port thermal discharges are compared to the predictions of a theory treating the dilution of merging multiple-port buoyant jets discharge from a row of equally spaced ports. The paper summarizes the considerable alteration of the Hirst [11] model necessary to adequately treat merging multiple jets. The essential features of the analysis are: (1) the gradual transition of the profiles from simple axisymmetric profiles to merging profiles and finally to fully merged, pseudo-slot, two-dimensional profiles, and (2) an entrainment based on the available entrainment surface. Results indicate that the overprediction of plume characteristics associated with certain other models as compared to experimental data may be overcome using such an analysis and that suitable prediction may be obtained.

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.

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