scholarly journals Numerical investigation of flow field around T-shaped spur dyke in a reverse-meandering channel

2021 ◽  
Author(s):  
Ravi Prakash Tripathi ◽  
K. K. Pandey
Keyword(s):  
Fluid Dynamics ◽  
Research Work ◽  
Flow Characteristics ◽  
Bed Shear Stress ◽  
Exit Channel ◽  
Meandering Channel ◽  
Structured Meshes ◽  
Fluent Software ◽  
Rng Turbulence Model ◽  
Moving Fluid

Abstract In this paper the flow characteristics near around T-shape spur dyke situated in reverse meandering channel having rigid bed is simulated using Renormalization Group (RNG) turbulence model with an ANSYS 2018 Fluent software. To solve the model in 3D ways we used Navier-Stroke's equation based on principle of conservation of mass and momentum within a moving fluid. For studying the flow characteristics, Computational Fluid Dynamics ware applied with all geometric parameter and the turbulence was simulated using (RNG) equations of model. In this simulation the structured meshes are used with different diameter and diameter of meshes is high at exit channel for obtaining accuracy in result. In this study we mainly focus on effect of Froude number on flow pattern and several other characteristics like velocity distribution, flow separation, bed shear stress distribution. The final result of this research work is compare with the condition when no structure is present in the channel.

scholarly journals Sediment and Cavitation Erosion in Francis Turbines—Review of Latest Experimental and Numerical Techniques

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1516
Author(s):  
Adnan Aslam Noon ◽  
Man-Hoe Kim
Keyword(s):  
Fluid Dynamics ◽  
Material Properties ◽  
Cavitation Erosion ◽  
Research Work ◽  
Flow Characteristics ◽  
Hydroelectric Power ◽  
Numerical Techniques ◽  
Power Turbine ◽  
Computational Fluid Dynamics Cfd ◽  
Components Analysis

Sediment and cavitation erosion of the hydroelectric power turbine components are the fundamental problems in the rivers of Himalayas and Andes. In the present work, the latest research conducted in both the fields by various investigators and researchers are discussed and critically analyzed at different turbine components. Analysis shows that both types of erosion depends on flow characteristics, surface, and erodent material properties. Design optimization tools, coalesced effect (CE) of sediment and cavitation erosion and well conducted experiments will yield results that are beneficial for erosion identification and reduction. Although some researchers have done experimental work on the coalesced effect (CE) of sediment and cavitation erosion, very limited Computational Fluid Dynamics (CFD) work is available in literature. The present research work will be beneficial for practitioners and researchers in the future to address the erosion problem successfully.

Efficiency prediction for storage chambers using computational fluid dynamics

1996 ◽  
Vol 33 (9) ◽  
pp. 163-170 ◽  
Author(s):  
Virginia R. Stovin ◽  
Adrian J. Saul
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Shear Stress ◽  
Particle Tracking ◽  
Critical Value ◽  
Complex Geometries ◽  
Bed Shear Stress ◽  
Breadth Ratio ◽  
Computational Fluid Dynamics Cfd ◽  
Simulated Flow

Research was undertaken in order to identify possible methodologies for the prediction of sedimentation in storage chambers based on computational fluid dynamics (CFD). The Fluent CFD software was used to establish a numerical model of the flow field, on which further analysis was undertaken. Sedimentation was estimated from the simulated flow fields by two different methods. The first approach used the simulation to predict the bed shear stress distribution, with deposition being assumed for areas where the bed shear stress fell below a critical value (τcd). The value of τcd had previously been determined in the laboratory. Efficiency was then calculated as a function of the proportion of the chamber bed for which deposition had been predicted. The second method used the particle tracking facility in Fluent and efficiency was calculated from the proportion of particles that remained within the chamber. The results from the two techniques for efficiency are compared to data collected in a laboratory chamber. Three further simulations were then undertaken in order to investigate the influence of length to breadth ratio on chamber performance. The methodology presented here could be applied to complex geometries and full scale installations.

Numerical Study on Flow Characteristics in High Multi-Stage Pressure Reducing Valve

2017 ◽  
Author(s):  
Fu-qiang Chen ◽  
Zhi-xin Gao ◽  
Jin-yuan Qian ◽  
Zhi-jiang Jin
Keyword(s):  
Energy Consumption ◽  
Numerical Study ◽  
Research Work ◽  
Flow Characteristics ◽  
Temperature Fields ◽  
Turbulent Dissipation ◽  
Technological Support ◽  
Multi Stage ◽  
Valve Opening ◽  
Pressure Reducing Valve

In this paper, a new high multi-stage pressure reducing valve (HMSPRV) is proposed. The main advantages include reducing noise and vibration, reducing energy consumption and dealing with complex conditions. As a new high pressure reducing valve, its flow characteristics need to be investigated. For that the valve opening has a great effect on steam flow, pressure reduction and energy consumption, thus different valve openings are taken as the research points to investigate the flow characteristics. The analysis is conducted from four aspects: pressure, velocity, temperature fields and energy consumption. The results show that valve opening has a great effect on flow characteristics. No matter for pressure, velocity or temperature field, the changing gradient mainly reflects at those throttling components for all valve openings. For energy consumption, in the study of turbulent dissipation rate, it can be found that the larger of valve opening, the larger of energy consumption. It can be concluded that the new high multi-stage pressure reducing valve works well under complex conditions. This study can provide technological support for achieving pressure regulation, and benefit the further research work on energy saving and multi-stage design of pressure reducing devices.

scholarly journals Solution of the conjugate problem of gas dynamics and heat transfer in structures with a large ratio of geometric scale values

2017 ◽  
pp. 69-74
Author(s):  
D. A. Romanyuk ◽  
S. V. Panfilov ◽  
D. S. Gromov
Keyword(s):  
Gas Dynamics ◽  
Software Package ◽  
Thermal State ◽  
Mathematical Formulation ◽  
Research Work ◽  
Conjugate Problem ◽  
Thermal Processes ◽  
Ansys Fluent ◽  
Fluent Software ◽  
Volume Method

Within the scope of the research work, we have developed the methods and software package for solving the conjugate heat and hydraulic problems based on the classical approach to performing hydraulic calculations and modeling thermal processes by means of the finite volume method in the ANSYS Fluent software package. The developed means allowed us to efficiently calculate the thermal state of complex technical objects. The study gives mathematical formulation of the methods and suggests the results of their approbation and verification

scholarly journals Heat Transfer and Slip Effects on the Mhd Peristaltic Flow of Viscous Fluid in A Tapered Microvessels: Application of Blood Flow Research

2019 ◽  
Vol 9 (1) ◽  
pp. 5384-5390
Keyword(s):  
Heat Transfer ◽  
Blood Flow ◽  
Research Work ◽  
Flow Characteristics ◽  
Peristaltic Flow ◽  
Pressure Level ◽  
Slip Parameter ◽  
Electrically Conducting ◽  
Electrically Conducting Fluid ◽  
Slip Effects

This research work is proposed at reporting heat transfer on the peristaltic flow of an electrically conducting fluid in a tapered microvessels under the lubrication theory. The proposed geometry analyzes the blood flow in the heart vessels and maintain the pressure level in the human body. The solutions for the distribution of axial velocity, temperature distribution, pressure gradient and stream function have been obtained analytically. The influences of many evolving parameters on the flow characteristics are revealed and deliberated with the assist of figures. The mathematical outcomes show that the trapped bolus enhances in size with increasing slip parameter but decreases with the increase of Grashof number.

Modelling Liquid Flow Through Carbon Nanotubes

2013 ◽  
pp. 297-309
Author(s):  
Faig Bakhman Ogli Naghiyev
Keyword(s):  
Mass Transfer ◽  
Continuum Hypothesis ◽  
Flow Characteristics ◽  
Bingham Fluid ◽  
Length Scale ◽  
Review Of The Literature ◽  
Nanoscale Systems ◽  
Flow Through ◽  
Intermolecular Distances ◽  
Moving Fluid

In this paper, the structure of a liquid and character of its flow in carbon nanotube is investigated. A review of the literature and the results of experiments show that the simulation of fluid flow for nanoscale systems should be based on the continuum hypothesis taking into account the quantized character of the liquid in the length scale of intermolecular distances. Consideration of the flow characteristics allowed construction of the analogy of behavior of the liquid in a nanotube with a flow of a viscoplastic Bingham fluid. A model of mass transfer of liquid in a nanotube, based on the possibility of forming an empty interlayer between the moving fluid particles and the particles of the wall of the nanotube, is presented.

scholarly journals Coronary artery decision algorithm trained by two-step machine learning algorithm

RSC Advances ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 4014-4022
Author(s):  
Young Woo Kim ◽  
Hee-Jin Yu ◽  
Jung-Sun Kim ◽  
Jinyong Ha ◽  
Jongeun Choi ◽  
...  
Keyword(s):  
Machine Learning ◽  
Fluid Dynamics ◽  
Decision Making ◽  
Coronary Artery ◽  
Learning Algorithm ◽  
Flow Characteristics ◽  
Machine Learning Algorithm ◽  
Decision Algorithm ◽  
Computational Fluid Dynamics Cfd ◽  
Biometric Features

A two-step machine learning (ML) algorithm for coronary artery decision making is introduced, to increase the data quality by providing flow characteristics and biometric features by aid of computational fluid dynamics (CFD).

scholarly journals Three-Dimensional Flow Characteristics in Slit-Type Permeable Spur Dike Fields: Efficacy in Riverbank Protection

Water ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 964 ◽  
Author(s):  
Shampa ◽  
Yuji Hasegawa ◽  
Hajime Nakagawa ◽  
Hiroshi Takebayashi ◽  
Kenji Kawaike
Keyword(s):  
Shear Stress ◽  
Longitudinal Velocity ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Efficient Solutions ◽  
Staggered Grid ◽  
Bed Shear Stress ◽  
Experimental Conditions ◽  
Alluvial Rivers ◽  
Spur Dike

This paper focuses on finding efficient solutions for the design of a highly permeable pile spur (or slit type) dike field used in morphologically dynamic alluvial rivers. To test the suitability of different arrangements of this type of permeable pile spur dike field, laboratory experiments were conducted, and a three-dimensional multiphase numerical model was developed and applied, based on the experimental conditions. Three different angles to the approach flow and two types of individual pile position arrangements were tested. The results show that by using a series of slit-type spurs, the approach velocity of the flow can be considerably reduced within the spur dike zone. Using different sets of angles and installation positions, this type of permeable spur dike can be used more efficiently than traditional dikes. Notably, this type of spur dike can reduce the longitudinal velocity, turbulence intensity, and bed shear stress in the near-bank area. Additionally, the deflection of the permeable spur produces more transverse flow to the opposite bank. Arranging the piles in staggered grid positions among different spurs in a spur dike field improves functionality in terms of creating a quasi-uniform turbulence zone while simultaneously reducing the bed shear stress. Finally, the efficacy of the slit-type permeable spur dike field as a solution to the riverbank erosion problem is numerically tested in a reach of a braided river, the Brahmaputra–Jamuna River, and a comparison is made with a conventional spur dike field. The results indicate that the proposed structure ensures the smooth passing of flow compared with that for the conventional impermeable spur structure by producing a lower level of scouring (low bed shear stress) and flow intensification.

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