scholarly journals Experimental Study on Flow Velocity Structure and Turbulence Characteristics in Open Channel with Biomimetic Grass

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Changjing Fu ◽  
Jinguo Wang ◽  
Tianlong Zhao ◽  
Yangming Xu ◽  
Yi Lv
Keyword(s):  
Velocity Field ◽  
Velocity Distribution ◽  
Flow Velocity ◽  
Open Channel ◽  
Oil And Gas ◽  
Velocity Structure ◽  
Water Channel ◽  
Vertical Plane ◽  
Velocity Variation ◽  
Probability Density Distribution

The problem of suspension treatment of oil and gas pipelines has been highly concerned by engineering construction units and researchers. Research shows that the bionic grass can effectively reduce the flow rate, promote sediment deposition, and control the development of the pipeline suspension area. The velocity distribution of open channel flow with bionic grass is very complex. The height and spacing of bionic grass will affect the flow velocity distribution. At present, the flow velocity in open channels containing bionic grass is mainly studied by measuring the velocity variation in the front, middle, and back of bionic grass, but few effective measurements are made for the full velocity field. This paper describes the use of modern means of an advanced test, using standard particle image velocimetry (PIV) measurements with bionic grass along the water channel to the vertical plane of the distribution of the velocity field. The probability density distribution, spatial correlation of pulsating velocity, turbulence intensity, Reynolds stress, and turbulent kinetic energy in the open channel after the protection section of bionic grass were further analyzed.

scholarly journals Experimental Study on the Influence Factors of Flow Velocity Structure and Turbulent Characteristics in Open Channel with Biomimetic Grass

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Changjing Fu ◽  
Jinguo Wang ◽  
Tianlong Zhao ◽  
Yi Lv
Keyword(s):  
Velocity Field ◽  
Velocity Distribution ◽  
Flow Velocity ◽  
Open Channel ◽  
Velocity Structure ◽  
Influence Factors ◽  
Vertical Plane ◽  
Velocity Variation ◽  
Probability Density Distribution ◽  
Turbulent Characteristics

The problem of suspension treatment of subsea oil-gas pipelines has been highly concerned by engineering construction units and researchers. The current research indicates that the bionic sea grass can effectively reduce the flow rate, promote sediment deposition, and control the development of the pipeline suspension area. The velocity distribution of open channel flow with bionic grass is very complex. The height and laying space of bionic grass will affect the flow velocity distribution. At present, the flow velocity in open channels with bionic grass is mainly studied by measuring the velocity variation at the front, middle, and back of bionic grass. Few effective measurements are made for the full velocity field. The velocity field distribution of bionic aquatic grass along the vertical plane is measured by using standard particle image velocimetry (PIV). The effects of height and laying space of bionic grass on probability density distribution, spatial correlation of pulsating velocity, turbulence intensity, Reynolds stress and turbulent kinetic energy in the open channel after the protection section of bionic grass are further analyzed.

Effects of Aeration Volume on Velocity Distribution of Fluid in Multi-Flora Biological Wastewater Treatment Reactor

2011 ◽  
Vol 255-260 ◽  
pp. 2740-2744 ◽  
Author(s):  
De Jun Bian ◽  
Qing Kai Ren ◽  
Li Guo Wan ◽  
Sheng Shu Ai ◽  
Xi Tian ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Velocity Distribution ◽  
Flow Velocity ◽  
Reaction Zone ◽  
Vertical Plane ◽  
Central Area ◽  
Biological Wastewater Treatment ◽  
Primary Reaction ◽  
Outer Race ◽  
Aeration Volume

The flow characteristics and effects of aeration volume on velocity distribution of the fluid in primary reaction zone of multi-flora biological wastewater treatment reactor were studied with clean water. Experimental results demonstrated that the fluid in primary reaction zone formed non-symmetrical cycle flow in the vertical plane with lower flow velocity in the central area and higher flow velocity in the peripheral area under the lifting action of the bubbles from perforated aerated pipe. As the aeration volume varied from1.0 m3/h to 2.2 m3/h, the flow velocity of central points had lower increased rate contrary to the peripheral points with higher increased rate in primary reaction area. Thus, the decreasing gradient of flow velocity of the primary reaction zone from the outer race to the center could be changed by controlling the aeration volume. For the design and operation of multi-flora biological wastewater treatment reactor, the results had important guiding significances that were listed out.

scholarly journals Experimental Study on the Effect of Triangular Plate Barrier Height on Flow Velocity Distribution in Open Channels

2021 ◽  
Vol 2 (2) ◽  
pp. 31-36
Author(s):  
Lhiung Phung Hwa
Keyword(s):  
Velocity Distribution ◽  
Flow Velocity ◽  
Open Channel ◽  
Pitot Tube ◽  
Closed Channel ◽  
Velocity Flow ◽  
Velocity Changes ◽  
Automatic Tool ◽  
Data Collection Technique ◽  
Narrow Opening

Open and closed channel flow flows are distinct, the flow in the channels will constantly change. The flow will also be altered if the water level or flow velocity changes. It was found that employing the Pitot Tube Portable yielded findings identical to those calculated by other methods. A water transfer system is made up of natural or artificial structures via which water is moved from one site to another. The carrier building may be open or closed, depending on whether you want to utilize it as a shipping or receiving location. An open channel with a relatively narrow opening at the top is known as an open conduit. The speed data collection technique is carried out vertically, with a review point as illustrated above. The velocity of the flow was measured using a Pitot Tube Portable Automatic tool. The results are entered into the Froude number (fr) after each review point to determine the type of velocity flow at each Review point. The normal flow velocity distribution pattern emerges at the measurement sites of 450 cm, 500 cm, and 550 cm.

Investigation on Velocity Distribution Around the Wrapping Wire in an Inner Subchannel of Fuel Pin Bundle

2012 ◽  
Author(s):  
Masahiro Nishimura ◽  
Hiroyuki Sato ◽  
Hideki Kamide ◽  
Hiroyuki Ohshima ◽  
Kazuyoshi Nagasawa ◽  
...  
Keyword(s):  
Refractive Index ◽  
Velocity Distribution ◽  
Flow Velocity ◽  
Fast Reactor ◽  
Horizontal Plane ◽  
Vertical Plane ◽  
Heat Removal ◽  
Water Model ◽  
Local Flow ◽  
Fuel Pin

A sodium cooled fast reactor is designed to attain a high burn-up core in commercialized fast reactor cycle systems. In high burn-up fuel subassemblies, deformation of fuel pin due to the swelling and thermal bowing may decrease local flow velocity via change of flow area in the subassembly and influence the heat removal capability. Therefore, it is important to obtain the flow velocity distribution in a wire wrapped pin bundle. In this study, water experiments were carried out to investigate the detailed velocity distribution in inner subchannel of the pin bundle geometry. These basic data are not only useful for understanding of pin bundle thermal hydraulics but also code validation. A wire-wrapped 3-pin bundle water model was applied to investigate the detailed velocity distribution in an inner subchannel surrounded by 3 pins with the wrapping wire. The test section consists of an irregular hexagonal acrylic duct tube and fluorinated resin pins which have nearly the same refractive index with that of water and a high light transmission rate. This refractive index matching enables to visualize the inner subchannel through the outer pins. The velocity distribution in the inner subchannel with the wrapping wire was measured by PIV (Particle Image Velocimetry) through two sides of the duct tube. Typical flow velocity conditions in the pin bundle were 1.6m/s (Re = 13,500) and 0.36m/s (Re = 2,700). Feature of stream regime in the subchannel existing wrapping wire was visualized in vertical and horizontal plane. The time averaged velocity field in the horizontal plane was reconstructed from the two vertical plane data in different directions. A detailed simulation code based on FEM was applied to the experimental analysis. The calculated velocity distributions were consistent with the experimental data.

scholarly journals Submerged flexible vegetation impact on open channel flow velocity distribution: An analytical modelling study on drag and friction

2019 ◽  
Vol 12 (2) ◽  
pp. 121-128 ◽  
Author(s):  
Jaan H. Pu ◽  
Awesar Hussain ◽  
Ya-kun Guo ◽  
Nikolaos Vardakastanis ◽  
Prashanth R. Hanmaiahgari ◽  
...  
Keyword(s):  
Velocity Distribution ◽  
Flow Velocity ◽  
Channel Flow ◽  
Open Channel ◽  
Open Channel Flow ◽  
Analytical Modelling ◽  
Flexible Vegetation ◽  
Vegetation Impact ◽  
Modelling Study

scholarly journals Study on Flow Velocity Distribution in Open Channel With Flexible Vegetation

2021 ◽  
Vol 12 ◽  
Author(s):  
Shiyu Wang ◽  
Yi Zhou ◽  
Tongshu Li ◽  
Song Li ◽  
Mingwu Zhang ◽  
...  
Keyword(s):  
Velocity Distribution ◽  
Flow Velocity ◽  
Flow Measurement ◽  
Open Channel ◽  
Maximum Flow ◽  
Distribution Model ◽  
Turbulence Structure ◽  
River Channels ◽  
Microscopic Mechanism ◽  
Flexible Vegetation

Ecological management of river channels is a hot topic for current sustainable development and flow measurement of ecological river is an important part. In this article, a flow velocity distribution model of the channel containing flexible vegetation is constructed from the vegetation riverbed theory and the bursting phenomenon to reveal the microscopic mechanism of the flow velocity distribution in the upper layer of vegetation. In the vegetation riverbed law, the effect of flexible vegetation is evaluated by the mixed length formula. The bursting phenomenon law considers the influence of the channel sidewalls on the flow and a two-dimensional velocity model is established by introducing the concept of average turbulence structure. The mechanism of the downward shift of the maximum flow velocity point on the channel sidewall is explained. The verification of the calculated velocity profiles is carried out based on data obtained in laboratory experiments. The results show that the combination of the two models can well describe the velocity distribution of the whole channel. At the end, the phenomenon of flow velocity zoning in open channel is discussed, which provides a solution for flow measurement in ecological channel.

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.

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