STILLING BASIN WITH A FLOW SWIRLING

2021 ◽  
pp. 79-86
Author(s):  
A. P. GURJEV ◽  
◽  
M. M. CHUMICHEVA ◽  
O. V. МАREEVA ◽  
A. S. VERHOGLYADOVA ◽  
...  
Keyword(s):  
Uniform Distribution ◽  
Inlet Section ◽  
Output Section ◽  
Stilling Basin ◽  
Main Disadvantage ◽  
Diversion Channel ◽  
Stilling Basins ◽  
Applied Design ◽  
The Given ◽  
Made In

In the given materials there is given an analysis of the operation of existing constructions of devices for dissipation of excess energy of idle water discharges at hydraulic engineering facilities. The most applied design for dissipation of fl ow energy in the practice of hydraulic building in the world is stilling basins with straight axis made in prismatic or trapezoidal shapes which is appealing in their simplicity. The main disadvantage of these stilling wells in case of their using together with tubular spillways, especially having several strings, is practical impossibility to provide uniform distribution of specific discharges at the outlet from the spillway. This is connected with the fact that with several strings it is difficult to provide uniform distribution of specific discharges in the inlet section of the stilling well, it causes appearance of unstable regimes during operation of the stilling basin, especially in case of spillway operation with incomplete front which makes them inapplicable exactly for multi-point tubular spillways. At the same time, by deforming the stilling basin well flow in the form of a spiral, it is possible to reduce the length of the spilling basin by creating the possibility of the planned symmetric spreading of the flow in the output section in the diversion channel of the stilling basin, allowing using it if necessary to repeatedly expand the flow behind the spillway.

Formally Normal Operators Having no Normal Extensions

1965 ◽  
Vol 17 ◽  
pp. 1030-1040 ◽  
Author(s):  
Earl A. Coddington
Keyword(s):  
Hilbert Space ◽  
Linear Operator ◽  
Null Space ◽  
Normal Operator ◽  
Closed Linear Operator ◽  
Normal Operators ◽  
The Given ◽  
Densely Defined ◽  
Made In

The domain and null space of an operator A in a Hilbert space will be denoted by and , respectively. A formally normal operatorN in is a densely defined closed (linear) operator such that , and for all A normal operator in is a formally normal operator N satisfying 35 . A study of the possibility of extending a formally normal operator N to a normal operator in the given , or in a larger Hilbert space, was made in (1).

scholarly journals Optimal synthesis of a four-bar linkage by method of controlled deviation

2004 ◽  
Vol 31 (3-4) ◽  
pp. 265-280 ◽  
Author(s):  
Radovan Bulatovic ◽  
Stevan Djordjevic
Keyword(s):  
Objective Function ◽  
Optimal Synthesis ◽  
Straight Line ◽  
Individual Comparison ◽  
Four Bar Linkage ◽  
The Given ◽  
Initial Selection ◽  
Selection Of ◽  
Process Calculation ◽  
Made In

This paper considers optimal synthesis of a four-bar linkage by method of controlled deviations. The advantage of this approximate method is that it allows control of motion of the coupler in the four-bar linkage so that the path of the coupler is in the prescribed environment around the given path on the segment observed. The Hooke-Jeeves?s optimization algorithm has been used in the optimization process. Calculation expressions are not used as the method of direct searching, i.e. individual comparison of the calculated value of the objective function is made in each iteration and the moving is done in the direction of decreasing the value of the objective function. This algorithm does not depend on the initial selection of the projected variables. All this is illustrated on an example of synthesis of a four-bar linkage whose coupler point traces a straight line, i.e. passes through sixteen prescribed points lying on one straight line. .

COMPARISON BETWEEN PIXE AND XRF FOR OLD JAPANESE COPPER COIN ANALYSIS

1999 ◽  
Vol 09 (03n04) ◽  
pp. 181-188 ◽  
Author(s):  
YOICHI HARUYAMA ◽  
MANABU SAITO ◽  
TAKAHIRO MUNEDA ◽  
MASAKI MITANI ◽  
RIE YAMAMOTO ◽  
...  
Keyword(s):  
Uniform Distribution ◽  
Elemental Concentration ◽  
Two Dimensional ◽  
Minor Components ◽  
Edo Period ◽  
Old Japanese ◽  
Copper Coin ◽  
Place Identification ◽  
Main Components ◽  
Made In

We have measured elemental concentration of old Japanese copper coins made in the Edo period (1600-1860) by PIXE and XRF to study the availability of elemental concentration analysis for production place identification of copper-based archaeological alloys. We also aimed to compare the effectiveness of these two methods for this purpose. We used 2.5 MeV proton beam for PIXE measurement. For XRF measurement we operated a XRF equipment with rhodium target at 50 kV Since elemental uniformity is indispensable for concentration analysis, we also measured the elemental distributions by SEM at 25 kV. Two dimensional images obtained by SEM showed nearly uniform distribution for iron, tin and antimony but not for lead. Besides of main components, copper and lead, many minor components were measured by PIXE and XRF. The relative concentrations of arsenic, silver, antimony and tin showed clear difference by the place the coins were made.

Circles on the Complex Plane

2021 ◽  
pp. 3-12
Author(s):  
A. Girsh
Keyword(s):  
Euclidean Space ◽  
Complex Plane ◽  
Euclidean Plane ◽  
Complex Space ◽  
Radical Center ◽  
Special Cases ◽  
Different Types ◽  
Different Dimensions ◽  
The Given ◽  
Made In

The Euclidean plane and Euclidean space themselves do not contain imaginary elements by definition, but are inextricably linked with them through special cases, and this leads to the need to propagate geometry into the area of imaginary values. Such propagation, that is adding a plane or space, a field of imaginary coordinates to the field of real coordinates leads to various variants of spaces of different dimensions, depending on the given axiomatics. Earlier, in a number of papers, were shown examples for solving some urgent problems of geometry using imaginary geometric images [2, 9, 11, 13, 15]. In this paper are considered constructions of orthogonal and diametrical positions of circles on a complex plane. A generalization has been made of the proposition about a circle on the complex plane orthogonally intersecting three given spheres on the proposition about a sphere in the complex space orthogonally intersecting four given spheres. Studies have shown that the diametrical position of circles on the Euclidean E-plane is an attribute of the orthogonal position of the circles’ imaginary components on the pseudo-Euclidean M-plane. Real, imaginary and degenerated to a point circles have been involved in structures and considered, have been demonstrated these circles’ forms, properties and attributes of their orthogonal position. Has been presented the construction of radical axes and a radical center for circles of the same and different types. A propagation of 2D mutual orthogonal position of circles on 3D spheres has been made. In figures, dashed lines indicate imaginary elements.

Impact of the Slurry Pond of the Tyrnyauz Tungsten-Molybdenum Complex on the Mountain Territories Environment

2018 ◽  
Vol 931 ◽  
pp. 1070-1075 ◽  
Author(s):  
Buzgigit M. Huchunayev ◽  
Oksana O. Dakhova ◽  
Svetlana A. Bekkiyeva ◽  
Svetlana B. Hatefova
Keyword(s):  
Negative Impact ◽  
Scientific Work ◽  
Land Resources ◽  
Molybdenum Complex ◽  
Atmospheric Air ◽  
Impact Reduction ◽  
The Given ◽  
Made In

The results of the Tyrnyauz tungsten-molybdenum Plant (TTMP) slurry pond settler environment impacts assessment are given in this scientific work, and the recommendations about the negative impact reduction on the environment are made. In the given work the characteristics of the environment state are investigated: atmospheric air, water objects and land resources.

scholarly journals Experimental Characterization of the Hydraulic Jump Profile and Velocity Distribution in a Stilling Basin Physical Model

Water ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1758
Author(s):  
Juan Macián-Pérez ◽  
Francisco Vallés-Morán ◽  
Santiago Sánchez-Gómez ◽  
Marco De-Rossi-Estrada ◽  
Rafael García-Bartual
Keyword(s):  
Free Surface ◽  
Energy Dissipation ◽  
Velocity Distribution ◽  
Physical Model ◽  
Hydraulic Jump ◽  
Surface Profile ◽  
Air Entrainment ◽  
Stilling Basin ◽  
Free Surface Profile ◽  
Stilling Basins

The study of the hydraulic jump developed in stilling basins is complex to a high degree due to the intense velocity and pressure fluctuations and the significant air entrainment. It is this complexity, bound to the practical interest in stilling basins for energy dissipation purposes, which brings the importance of physical modeling into the spotlight. However, despite the importance of stilling basins in engineering, bibliographic studies have traditionally focused on the classical hydraulic jump. Therefore, the objective of this research was to study the characteristics of the hydraulic jump in a typified USBR II stilling basin, through a physical model. The free surface profile and the velocity distribution of the hydraulic jump developed within this structure were analyzed in the model. To this end, an experimental campaign was carried out, assessing the performance of both, innovative techniques such as the time-of-flight camera and traditional instrumentation like the Pitot tube. The results showed a satisfactory representation of the free surface profile and the velocity distribution, despite some discussed limitations. Furthermore, the instrumentation employed revealed the important influence of the energy dissipation devices on the flow properties. In particular, relevant differences were found for the hydraulic jump shape and the maximum velocity positions within the measured vertical profiles, when compared to classical hydraulic jumps.

Torque Rheological Properties of Bamboo Flour/PP Composites

2011 ◽  
Vol 391-392 ◽  
pp. 138-142
Author(s):  
Wen Bin Yang ◽  
Ming Xin Zhang ◽  
En Hui Chen
Keyword(s):  
Rheological Behavior ◽  
Flow Behavior ◽  
Orthogonal Test ◽  
Weight Percentage ◽  
Two Factors ◽  
Pp Composites ◽  
Bamboo Flour ◽  
Reinforced Thermoplastics ◽  
The Given ◽  
Made In

The rheological behavior of plant flour reinforced thermoplastics composites is very important to practical industry, however few research especially research about bamboo flour reinforced polypropylene(PP) composites is available regarding rheological field. In this paper, the torque rheometer made in Shanghai was used to examine the flow behavior of bamboo flour filled PP composites. The orthogonal test was adopted to analyze how three factors(weight percentage of bamboo, weight percentage of MAPP and rotate speed) influence the behavior of composites. The result indicated that bamboo flour filled PP composites was pseudo-plastics or shear-thinning flow under the experimental condition investigated. The effect of weight percentage of bamboo on rheological peoperties was signigficant,but the effect of both of the rest of two factors on rheological was not significant under the given experimental condition.

scholarly journals Analysis of the Flow in a Typified USBR II Stilling Basin through a Numerical and Physical Modeling Approach

Water ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 227 ◽  
Author(s):  
Juan Francisco Macián-Pérez ◽  
Rafael García-Bartual ◽  
Boris Huber ◽  
Arnau Bayon ◽  
Francisco José Vallés-Morán
Keyword(s):  
Physical Model ◽  
Hydraulic Jump ◽  
Numerical Approach ◽  
Free Surface Flows ◽  
United States Bureau ◽  
Bureau Of Reclamation ◽  
Stilling Basin ◽  
Modeling Approach ◽  
Stilling Basins ◽  
Energy Dissipation Devices

Adaptation of stilling basins to higher discharges than those considered for their design implies deep knowledge of the flow developed in these structures. To this end, the hydraulic jump occurring in a typified United States Bureau of Reclamation Type II (USBR II) stilling basin was analyzed using a numerical and experimental modeling approach. A reduced-scale physical model to conduct an experimental campaign was built and a numerical computational fluid dynamics (CFD) model was prepared to carry out the corresponding simulations. Both models were able to successfully reproduce the case study in terms of hydraulic jump shape, velocity profiles, and pressure distributions. The analysis revealed not only similarities to the flow in classical hydraulic jumps but also the influence of the energy dissipation devices existing in the stilling basin, all in good agreement with bibliographical information, despite some slight differences. Furthermore, the void fraction distribution was analyzed, showing satisfactory performance of the physical model, although the numerical approach presented some limitations to adequately represent the flow aeration mechanisms, which are discussed herein. Overall, the presented modeling approach can be considered as a useful tool to address the analysis of free surface flows occurring in stilling basins.

Experimental Study of the Type VI Stilling Basin Performance

2015 ◽  
Vol 137 (3) ◽  
Author(s):  
Seyed Sobhan Aleyasin ◽  
Nima Fathi ◽  
Peter Vorobieff
Keyword(s):  
Experimental Study ◽  
Kinetic Energy ◽  
River Flow ◽  
Doppler Velocimetry ◽  
Huge Amount ◽  
Stilling Basin ◽  
Stilling Basins ◽  
Turbulence Data ◽  
Flow Turbulence ◽  
Acoustic Doppler Velocimetry

Understanding the estuarine turbulent flow from dams, channels, and pipes, as well as the river flow are very important due to the potential to cause damage to the bed of the river or channel and cause scouring of structures such as the saddles of bridges, because of the huge amount of the kinetic energy carried by the flow. One of the most efficient yet simple ways to dissipate this energy is to install a stilling basin at the discharge point to calm the flow. Turbulence data were recorded using acoustic Doppler velocimetry (ADV) for type VI2 of stilling basins for pipe outlets. During the study, various splitters and a cellular baffle were placed in the stilling basin, and the baffle locations were changed to assess the effect on the energy dissipation. Velocity at several locations in the basin was measured for different Froude numbers to investigate the effect of flow rate. Based on the findings of the experiments, several suggestions regarding the efficiency and geometry of stilling basins were made.

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