scholarly journals 3D-PIV Measurement for EHD Flow of Spiked Tubular Electrode Corona Discharge in Wide Electrostatic Precipitator

2020 ◽  
Vol 20 (4) ◽  
pp. 178-186
Author(s):  
Dongjie Yan ◽  
Ziang Zhang ◽  
Zhenyang Li ◽  
Ya Yu ◽  
Hao Gong ◽  
...  
Keyword(s):  
Corona Discharge ◽  
Flow Velocity ◽  
Fine Particles ◽  
Electrostatic Precipitator ◽  
Three Dimensional ◽  
Primary Flow ◽  
Cross Sectional ◽  
Piv Measurement ◽  
The Impact ◽  
Tubular Electrode

AbstractThe electrohydrodynamic (EHD) flow induced by a corona discharge has an important influence on the movement and collection of fine particles in an electrostatic precipitator. In this paper, three-dimensional particle image velocimetry (3D-PIV) is used to investigate the impact of different primary flow velocities and applied voltage on diffusion and transport of the spiked tubular electrode corona discharge EHD flow in a wide type electrostatic precipitator. In order to measure the flow characteristics of different positions of a spiked tubular electrode, the PIV measurements are carried out in several cross-sectional planes along the ESP duct. From 2D flow streamlines, in plane 1 (where the tip of the spike is oriented in the direction of primary flow), the velocity of the counter-clockwise vortex caused by the EHD flow near the plate decreases as the primary flow velocity increases. However, in plane 3 (where the tip direction is opposite to the primary flow), two vortices rotate adversely, and the flow velocity of the clockwise vortex near the plate increases as the primary flow velocity increases. Flow velocity increasing near the plate makes the particles deposited on the plate more easily to be re-entrained. It can be found in the three-dimensional analysis of the flow field that there are mainly “ascending vortex” and downward tip jet in the three observation planes. There is a discrepancy (in terms of distribution region and the magnitude of velocity) between the three-dimensional characteristics of these vortices and tip jets in the different cross-sectional planes.

scholarly journals Experimental Investigations of Interactions between Sand Wave Movements, Flow Structure, and Individual Aquatic Plants in Natural Rivers: A Case Study of Potamogeton Pectinatus L.

Water ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 1166 ◽  
Author(s):  
Łukasz Przyborowski ◽  
Anna Łoboda ◽  
Robert Bialik
Keyword(s):  
Flow Velocity ◽  
Three Dimensional ◽  
Potamogeton Pectinatus ◽  
Sand Wave ◽  
Experimental Investigations ◽  
Cross Sectional ◽  
Bending Tests ◽  
Long Duration ◽  
Elevation Changes

Long-duration measurements were performed in two sandy bed rivers, and three-dimensional (3D) flow velocity and bottom elevation changes were measured in a vegetated area and in a clear region of a river. Detailed flow velocity profiles downstream and upstream of a single specimen of Potamogeton pectinatus L. were obtained and the bed morphology was assessed. Potamogeton plants gathered from each river were subjected to tensile and bending tests. The results show that the existence of the plants was influenced by both bottom and flow conditions, as the plants were located where water velocity was lower by 12% to 16% in comparison to clear region. The characteristics of the flow and sand forms depended on the cross-sectional arrangement of the river, e.g., dunes were approximately four times higher in the middle of the river than in vegetated regions near the bank. Furthermore, the studied hydrophytes were too sparse to affect water flow and had no discernible impact on the sand forms’ movements. The turbulent kinetic energy downstream of a single plant was reduced by approximately 25%. Additionally, the plants’ biomechanical characteristics and morphology were found to have adjusted to match the river conditions.

scholarly journals Effect of shear stress on the wall of technological pipelines at a gas condensate field on the intensity of carbon dioxide corrosion

2020 ◽  
Vol 244 ◽  
pp. 439-447
Author(s):  
Aleksandr Ponomarev ◽  
Aleksandr Yusupov
Keyword(s):  
Carbon Dioxide ◽  
Shear Stress ◽  
Flow Velocity ◽  
Three Dimensional ◽  
Gas Condensate ◽  
Carbon Dioxide Corrosion ◽  
Area Of Interest ◽  
Corrosion Intensity ◽  
Rational Operation ◽  
The Impact

The object of the study is a section of the gas and gas condensate collection system, consisting of an angle throttle installed on a xmas tree and a well piping located after the angle throttle. The aim of the study is to assess the impact of the flow velocity and wall shear stress (WSS) on the carbon dioxide corrosion rate in the area of interest and to come up with substantiated recommendations for the rational operation of the angle throttle in order to reduce the corrosion intensity. In the course of solving this problem, a technique was developed and subsequently applied to assess the influence of various factors on the rate of carbon dioxide corrosion. The technique is based on a sequence of different modeling methods: modeling the phase states of the extracted product, three-dimensional (solid) modeling of the investigated section, hydrodynamic flow modeling of the extracted product using the finite volume method, etc. The developed technique has broad possibilities for visualization of the obtained results, which allow identifying the sections most susceptible to the effects of carbon dioxide corrosion. The article shows that the average flow velocity and its local values are not the factors by which it is possible to predict the occurrence of carbon dioxide corrosion in the pipeline section after the angle throttle. The paper proves that WSS has prevailing effect on the corrosion intensity in the section after the angle choke. The zones of corrosion localization predicted according to the technique are compared with the real picture of corrosion propagation on the inner surface of the pipe, as a result of which recommendations for the rational operation of the angle throttle are formed.

scholarly journals Detailed Images for Sustainability Development in Cross-Sectional Human Anatomy

2019 ◽  
Vol 21 (2) ◽  
pp. 27-37
Author(s):  
Dzintra Kažoka ◽  
Māra Pilmane
Keyword(s):  
Teaching And Learning ◽  
Three Dimensional ◽  
Magnetic Resonance Images ◽  
Human Anatomy ◽  
Cross Sectional ◽  
Interactive Tools ◽  
Group I ◽  
Study Process ◽  
Basic Studies ◽  
The Impact

Abstract In medical education and preclinical, clinical and transdisciplinary studies, tutors should be able to perform and offer qualitative study courses with more articulated perspective on higher educational sustainable development in higher education. Digital images have found their direct way to education in different medical areas. The aims of the study are to assess and verify the impact of cross-sectional images on the study process of Human Anatomy. In 2018, two randomly selected groups of 200 students from 2nd study year, Faculty of Medicine (Rīga Stradiņš University) were asked by tutors to identify several anatomical structures, using a three-dimensional virtual dissection table “Anatomage”. Group I analyzed cross-sectional images after cutting and segmentation of human body with interactive tools. Group II studied X-ray pictures, computerized tomography scans and magnetic resonance images of different regions and systems. The present paper focuses on the rate of cross-sectional image effectiveness in both groups. Analyzed detailed images represent their role in teaching and learning of Human Anatomy. Interpretation of these medical images will require very deep anatomical knowledge from basic studies until clinical courses.

Water Entry of a Wedge by Hydroelastic Orthotropic Plate Theory

1999 ◽  
Vol 43 (03) ◽  
pp. 180-193 ◽  
Author(s):  
Odd M. Faltinsen
Keyword(s):  
Impact Velocity ◽  
Cross Sections ◽  
Orthotropic Plate ◽  
Plate Theory ◽  
Three Dimensional ◽  
Water Entry ◽  
Natural Period ◽  
Cross Sectional ◽  
Flow Effects ◽  
The Impact

Water entry of a hull with wedge-shaped cross sections is analyzed. The stiffened platings between two transverse girders on each side of the keel are separately modeled. Orthotropic plate theory is used. The effect of structural vibrations on the fluid flow is incorporated by solving the two-dimensional Laplace equation in the cross-sectional fluid domain by a generalized Wagner's theory. The coupling with the plate theory provides three-dimensional flow effects. The theory is validated by comparison with full-scale experiments and drop tests. The importance of global ship accelerations is pointed out. Hydrodynamic and structural error sources are discussed. Systematic studies on the importance of hydroelasticity as a function of deadrise angle and impact velocity are presented. This can be related to the ratio between the wetting time of the structure and the greatest wet natural period of the stiffened plating. This ratio is proportional to the deadrise angle and inversely proportional to the impact velocity. A small ratio-means that hydroelasticity is important and a large ratio means that hydroelasticity is not important.

scholarly journals Characterization and Control for the Laminar Flow of Liquid Polyurethane System in a Wide Angle Diffuser with Transversely Arrayed Obstacles

2020 ◽  
Vol 10 (4) ◽  
pp. 1228
Author(s):  
Son ◽  
Lee ◽  
Chang
Keyword(s):  
Laminar Flow ◽  
Flow Velocity ◽  
Three Dimensional ◽  
Flow Uniformity ◽  
Cross Sectional ◽  
Lumped Parameter ◽  
Vorticity Vector ◽  
Rms Error ◽  
Sectional Shape ◽  
And Control

In the manufacturing process of hard-board poly-urethane foams, the uniformity is a very important issue for the raw compound of the liquid poly-urethane system flow for the quality control of such products. One of the universal methods to generate more uniform flow is that some obstacles are located inside the diffuser at the end of injector. For the regime of non-Newtonian laminar flow, better flow uniformity can be achieved with the enhancement of mixing in the wake after the resistive obstacles. In this research, the parametric study is made for the gap interval between adjacent obstacle components as well as the cross-sectional shape with a computational fluid dynamics (CFD) technique. The flow fields around circular and elliptic cylinders are visualized for flow velocity and vorticity with the comparison of root-mean-square (RMS) error for the deviation of velocity at the outlet as a lumped parameter to estimate flow uniformity and mixing. When the blockage ratio is fixed 0.3 for the pipe of Reynolds number 58.5 based on its diameter, eliminating the effect of wall boundary ratio with the classical Blasius velocity profile, the RMS error is reduced 77% to 92% from the baseline case in the case of 60%-diameter gaps for the figure of circles and 2:1 longitudinal ellipse, respectively. The flow is visualized around obstacle components with vorticity as well as flow velocity where the three-dimensional components of vorticity vector are also elucidated in physics for the evolution of complex multi-dimensional flow wake.

scholarly journals Impact Response and Damage Characteristics of Carbon Fiber Reinforced Aluminum Laminates Under Low Velocity Impact Loading

2020 ◽  
Vol 9 (4) ◽  
pp. 1831-1837
Keyword(s):  
Impact Energy ◽  
Impact Load ◽  
Three Dimensional ◽  
Low Velocity Impact ◽  
Fe Model ◽  
Low Velocity ◽  
Fiber Layer ◽  
Cross Sectional ◽  
Velocity Impact ◽  
The Impact

CARALL hybrid material has been extensively used in the aircraft structure due to their competitive impact strength. Low velocity impact test is utilized to evaluate the impact and damage properties for such material. It is also employed to observe complex damage mechanisms. A numerical modelling is an alternative way for impact assessment. This paper investigates the impact and damage properties under low velocity impact using numerical modeling and experimental work. A three-dimensional (3D) finite element (FE) model was devolved and validated with two studies from the literature. This model was meshed with solid elements. It was subjected to 2.4 m/s impact velocity and to 10 J impact energy. Absorbed energy, penetration, impact load and damage morphology were obtained. The impact energy was efficiently absorbed by the material. Both aluminum alloy layers underwent plastic deformation whereas the fiber layer failed. A macroscopic cross-sectional morphology was presented using the FE model. An agreement between the numerical and the experiment results were achieved and discussed.

The Research of Models for TKY Tubular Joint Welds in Ultrasonic Phased Array Inspection

2013 ◽  
Vol 779-780 ◽  
pp. 26-33
Author(s):  
Ming Hui Lu ◽  
Hong Liang Shao ◽  
Jun Jie Chang ◽  
Xun Feng Liu
Keyword(s):  
Mathematical Model ◽  
Three Dimensional ◽  
Ultrasonic Pulse ◽  
Cross Sectional ◽  
Shaped Tube ◽  
Ultrasonic Phased Array ◽  
Tubular Joint ◽  
Marine Engineering ◽  
Pulse Echo ◽  
The Impact

In order to solve the problem of locating defects from TKY node structure weld using for marine engineering , the article present a new approach of establishing TKY’s mathematical model to replace the traditional method of Graphic analytic method, which uses the computer to carry on the drawing. Firstly three-dimensional mathematical model of the Y-shaped tube node is made, based on what it work out the equation of the cross-sectional on different position of weld by introducing the concept of intersecting angle φ, eventually it establish the two dimensional mathematical model of cross-sectional . In the end of the article, some experimental examples show the effectiveness of the models, which testify that using computer graphics to evaluate ultrasonic pulse-echo is more effective , smaller error, higher working efficiency and reduces the impact of human factors greatly.

scholarly journals The Vibration of Tubular Beam Conveying Fluid with Variable Cross Section

2020 ◽  
Vol 65 (1) ◽  
pp. 56-62
Author(s):  
Mohamed Gaith
Keyword(s):  
Flow Velocity ◽  
Cross Section ◽  
Natural Frequencies ◽  
Variable Cross Section ◽  
System Stability ◽  
Variable Cross ◽  
Cross Sectional ◽  
Critical Flow Velocity ◽  
Constant Flow Rate ◽  
The Impact

The dynamics and stability of flow induced vibration of flow conveying in pipes particularly in case of high velocity flow may lead to severe damage. Predicting the circular natural frequencies and critical fluid velocities is an important tool in design and prevent system failures. In this study transverse dynamic response of simply supported pipe with variable tubular cross sectional area carrying fluid with a constant flow rate is investigated. Euler Bernoulli's beam theory is used to model the pipe. Hamilton's principle will be used to produce the governing equation of motion for the system. The resulting partial differential equation is solved using Galerkin's technique. The impact of the flow velocity and non-uniform variable cross section on the natural frequencies of the system, critical flow velocity and system stability is presented.

An Assessment of the Potential of Tidal Power From Minas Passage, Bay of Fundy, Using Three-Dimensional Models

2011 ◽  
Author(s):  
Richard Karsten
Keyword(s):  
Numerical Simulations ◽  
3D Structure ◽  
Three Dimensional ◽  
Tidal Currents ◽  
Total Power ◽  
Bay Of Fundy ◽  
Three Dimensional Model ◽  
Cross Sectional ◽  
Flow Through ◽  
The Impact

Large tidal currents exist in Minas Passage, which connects Minas Basin to the Bay of Fundy off the northwestern coast of Nova Scotia. The strong currents through this deep, narrow channel make it a promising location for the generation of electrical power using instream turbines. These strong currents are clearly illustrated in the results of a high-resolution, three-dimensional model of the flow through Minas Passage presented here. The simulations also clearly indicate the asymmetry of the flood and ebb tides and the 3D structure of the flow. A previous study has indicated that as much as 7000 MW could be extracted from the tidal currents through Minas Passage. However, this estimate was based on a complete fence of turbines across the passage, in essence a tidal barrage. In this paper, the power potential of partial turbine fences is examined. In order to estimate the power potential of turbine arrays, the theory of partial turbine fences is adapted to the particular dynamics of Minas Passage. The theory estimates the potential power of the fence and the change in flow that would result. The results are presented in terms of the portion of the cross-sectional area that the turbines occupy and the drag coefficient of the turbines. When the turbine fence occupies a large portion of the passage, the potential power of the fence rises significantly, to a value much larger than estimates based on the kinetic energy flux. The increase in power comes from the increased tidal head that a large turbine fence creates and the resulting increase in the turbine drag. We also present the efficiency of the turbine fence — given as the ratio of the power associated with the turbine drag over the total power extracted from the flow — and the impact of the turbines on the tidal flow. The results of the theory are compared to numerical simulations of the flow through the passage with turbines represented as regions of increased drag. The numerical simulations give power values that are three to six time as high as the theory suggests is possible. This discrepancy is examined by plotting the changes in tidal currents caused by the turbine fence.

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