scholarly journals Velocity Field Characteristics at the Inlet to a Pipe Culvert

2014 ◽  
Vol 61 (3-4) ◽  
pp. 127-140 ◽  
Author(s):  
Tomasz Kolerski ◽  
Paweł Wielgat
Keyword(s):  
Velocity Field ◽  
Velocity Distribution ◽  
Flow Velocity ◽  
Flow Structure ◽  
Laboratory Tests ◽  
Three Dimensional ◽  
Acoustic Doppler Velocimeter ◽  
Reynolds Stresses ◽  
Instantaneous Flow ◽  
Significant Damage

Abstract A poorly designed culvert inlet structure causes scouring, which can lead to the collapse of the culvert and significant damage to the neighboring land. A set of laboratory tests was evaluated to examine velocity distribution at the culvert inlet. A three-dimensional acoustic Doppler velocimeter was used to measure instantaneous flow velocity upstream of the culvert. The analysis of mean velocities, turbulence strength, and Reynolds stresses was performed to understand the flow structure near the culvert entrance.

Study on Flow Velocity Field of Local Scour around the Pier Protected by the Sediment Storage Dam

2012 ◽  
Vol 594-597 ◽  
pp. 1975-1978
Author(s):  
Hai Jing Zhao ◽  
Dan Xun Li ◽  
Xing Kui Wang
Keyword(s):  
Velocity Field ◽  
Flow Velocity ◽  
Physical Model ◽  
Model Test ◽  
Three Dimensional ◽  
Local Scour ◽  
Physical Model Test ◽  
Three Dimensional Flow ◽  
Sediment Storage ◽  
Flow Velocity Field

Aimed at the representative project which is protected by the downstream sediment storage dam, three dimensional flow velocity field in local scour area around the separate bridge pier via physical model test was studied. The influences of shaping the eroded pit caused by the velocities in different directions were analyzed. The distribution results of flow velocity field in local scour pit near the pier protected by the sediment storage dam, deduced from the paper, will provide references for the defensive design of bridge projects.

Three-dimensional study of spatial submerged hydraulic jump

2007 ◽  
Vol 34 (9) ◽  
pp. 1140-1148 ◽  
Author(s):  
H K Zare ◽  
R E Baddour
Keyword(s):  
Velocity Field ◽  
Hydraulic Jump ◽  
Three Dimensional ◽  
Head Loss ◽  
Acoustic Doppler Velocimeter ◽  
Hydraulic Jumps ◽  
Orthogonal Components ◽  
Sequent Depth ◽  
Channel Bottom ◽  
Submerged Hydraulic Jump

A three-dimensional (3D) study of spatial submerged hydraulic jumps (SSHJs) was carried out using a physical model for Froude numbers Fr1 = 2.00 and 3.75 and width ratios α = 0.20 and 0.33. Three orthogonal components of the velocity field were obtained with an acoustic Doppler velocimeter (ADV). The 3D velocity field has indicated that the jump consisted of a central jet-like flow, close to the channel bottom, surrounded by vertical and horizontal circulations (rollers). The circulation was predominantly in vertical planes in the channel central region of the flow and in horizontal planes close to the walls. Vertical and horizontal profiles of stream-wise velocity characterized the 3D roller with two length scales, Lrv and Lrh. The strength of the roller was stronger close to the walls than at the centreline of the jump. Sequent depth and energy head loss for submerged symmetric hydraulic jumps are discussed in terms of the submergence ratio S = y3/y2.Key words: hydraulic jump, spatial, submerged, roller length, sequent depth, energy dissipation.

Simulation of Simplified Three-Dimensional Space Flow Velocity Field in Reservoir on the Condition of Unsteady Flow and its Application

2012 ◽  
Vol 203 ◽  
pp. 514-518
Author(s):  
Shi Ping Fan ◽  
Jian Ming Yang ◽  
Min Quan Feng ◽  
Bang Min Zheng
Keyword(s):  
Numerical Calculation ◽  
Velocity Field ◽  
Flow Field ◽  
Unsteady Flow ◽  
Flow Velocity ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Flow Velocity Field ◽  
Flood Period ◽  
Three Dimensional Space

In view of the complexity of the conventional simulation calculation method of three-dimensional flow field for the reservoir, and to analysis of the change of the reservoir’s flow field in flood period, in this paper, based on the unsteady flow numerical calculation, the simulation method for three-dimensional space flow velocity field of the reservoir in flood period was studied and applied to the Wenyuhe Reservoir. First refining the actual extraction of grid, and then having an unsteady flow numerical calculation for the reservoir, finally through layering and stripping the grid, three-dimensional space flow velocity field the reservoir on the condition of unsteady flow has been studied. The results showed that the reservoir velocity along the flow direction is becoming smaller, and surface velocity is fast; with the flow increase gradually, the unsteady flow has a great effect on the flow field of the reservoir’s concave bank. The grid can at will encryption, so the calculation precision can be effectively controlled and the process of simulation is easy to be programmed. The research results can simplify the complexity of the reservoir for three-dimensional numerical simulation, and up to providing theoretical support for reservoir flood control.

scholarly journals Three-Dimensional Prescribed Velocity Blade Row Design

1990 ◽  
Author(s):  
V. Molnar ◽  
F. Ridzon ◽  
V. Adame
Keyword(s):  
Surface Modification ◽  
Velocity Distribution ◽  
Flow Velocity ◽  
Three Dimensional ◽  
Blade Profile ◽  
Profile Modification ◽  
Flow Surface ◽  
Blade Row ◽  
Actual Flow ◽  
Turbomachine Blade

A method for 3D turbomachine blade row design is presented as a subsequent tasks loop. The design follows the concept of the S1 and S2 streamsurfaces. A set of S1 surfaces is used for blade profile modification and a S2 mid-surface is used for hub and casing flow surface modification. A difference between target and actual flow velocity distribution is used to control iteration procedures for succesive geometry changes of an initial (original) blade row geometry. The design subroutines are added to standard direct codes. Results for several design cases are presented and discussed.

Three-dimensional numerical simulation of velocity field distribution in an oxy-coal combustor-melter-separator furnace

2021 ◽  
Vol 118 (5) ◽  
pp. 510
Author(s):  
Yao-zong Shen ◽  
Kai Zhao ◽  
Zheng Kong ◽  
Yu-zhu Zhang ◽  
Yan Shi ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Velocity Field ◽  
Velocity Distribution ◽  
Molten Pool ◽  
Dead Zone ◽  
Sudden Change ◽  
Three Dimensional ◽  
Maximum Velocity ◽  
Simulation Method ◽  
Distribution Area

In view of the influence of tuyere layout change on velocity field in oxy-coal combustor-melter-separator furnace, three-dimensional numerical simulation method was used to compare the distribution of velocity field in the furnace under different tuyere layout. The purpose is to explore the influence of the velocity distribution on the molten pool flow in the process of multi-tuyere injection. It is shown that the maximum velocity of the upper and lower tuyeres is 60 m/s and 50 m/s. And the change of tuyere has a significant effect on the velocity distribution in the molten pool, and the sudden change of velocity near the tuyere will trigger a certain scale of gyratory zone. In addition, the change of tuyere arrangement will result in the concentration of velocity distribution in the molten pool and the increase of flow dead zone, while the change of tuyere spacing will not only promote the increase of flow dead zone, but also reduce the velocity distribution area.

scholarly journals Velocity Distribution Associated With EUV Disturbances Caused by Eruptive MFR

2021 ◽  
Vol 8 ◽  
Author(s):  
Zhixing Mei ◽  
Qiangwei Cai ◽  
Jing Ye ◽  
Yan Li ◽  
Bojing Zhu
Keyword(s):  
Velocity Field ◽  
Velocity Distribution ◽  
Extreme Ultraviolet ◽  
Source Region ◽  
Three Dimensional ◽  
Vortex Center ◽  
Complex Velocity ◽  
Dynamical Interaction ◽  
Moving Plasma ◽  
Mass Ejection

Extreme ultraviolet (EUV) disturbances are ubiquitous during eruptive phenomena like solar flare and Coronal Mass Ejection (CME). In this work, we have performed a three-dimensional (3D) magnetohydrodynamic numerical simulation of CME with an analytic magnetic fluxrope (MFR) to study the complex velocity distribution associated with EUV disturbances. When the MFR erupts upward, a fast shock (FS) appears as a 3D dome, followed by outward moving plasma. In the center of the eruptive source region, an expanding CME bubble and a current sheet continuously grow, both of which are filled by inward moving plasma. At the flanks of the CME bubble, a complex velocity distribution forms because of the dynamical interaction between inward and outward plasma, leading to the formation of slow shock (SS) and velocity separatrix (VS). We note two types of vortices near the VS, not mentioned in the preceding EUV disturbance simulations. In first type of vortex, the plasma converges toward the vortex center, and in the second type, the plasma spreads out from the center. The forward modeling method has been used to create the synthetic SDO/AIA images, in which the eruptive MFR and the FS appear as bright structures. Furthermore, we also deduce the plasma velocity field by utilizing the Fourier local correlation tracking method on the synthetic images. However, we do not observe the VS, the SS, and the two types of vortices in this deduced velocity field.

scholarly journals Analysis of the Flow Pattern and Flow Rectification Measures of the Side-Intake Forebay in a Multi-Unit Pumping Station

Water ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2025
Author(s):  
Ahmed Nasr ◽  
Fan Yang ◽  
Yiqi Zhang ◽  
Tieli Wang ◽  
Mahmoud Hassan
Keyword(s):  
Numerical Simulation ◽  
Velocity Distribution ◽  
Flow Velocity ◽  
Flow Pattern ◽  
Three Dimensional ◽  
Operating Efficiency ◽  
Water Tank ◽  
Three Dimensional Model ◽  
Pumping Station ◽  
Area Reduction

To improve the problem of turbulence in the forebay of the lateral inlet pumping station, a typical lateral inlet pumping station project in Xuzhou, Jiangsu Province, China was taken as the research object. The forebay of the pumping station is a building connecting the river channel and the pumping station into the water tank. Based on the Reynolds-averaged Navier-Stokes (RANS) law and the turbulence model, the computational fluid dynamics method (CFD) technology compares and analyzes the numerical simulation with or without rectification measures for the forebay of the lateral intake pumping station when multiple units are operating. The three-dimensional model was created by SolidWorks modeling software and the numerical simulation simulated by CFX-ANSYS. To alter the flow pattern in the forebay of the pumping station, various rectification measures were chosen. Internal rectification flow patterns in the forebay under multiple plans, uniformity of flow velocity distribution in the measuring section, and vortex area reduction rates are investigated and compared. Based on the analysis and comparison of numerical simulation results, when the parabolic wall and some rectification piers are set significantly it improves the flow pattern of the forebay of the lateral inlet pumping station. It also makes the flow pattern of the inlet pool better and increases the uniformity of the flow velocity distribution by 8%. Further, it reduced the vortex area by 70%, effectively improving the operating efficiency of the pump. The research results of this paper provide a technical reference for the improvement of the flow pattern in the forebay of the lateral inlet pumping station.

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