scholarly journals Experimental and Numerical Investigation of Preferential Flow in Fractured Network with Clogging Process

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Xiaobing Chen ◽  
Jian Zhao ◽  
Li Chen
Keyword(s):  
Velocity Field ◽  
Cross Sections ◽  
Preferential Flow ◽  
Pressure Head ◽  
Fracture Network ◽  
Navier Stokes ◽  
Single Fracture ◽  
Navier Stokes Equation ◽  
Physical Experiments ◽  
Fractured Network

In this study, physical experiments and numerical simulations are combined to provide a detailed understanding of flow dynamics in fracture network. Hydraulic parameters such as pressure head, velocity field, Reynolds number on certain monitoring cross points, and total flux rate are examined under various clogging conditions. Applying the COMSOL Multiphysics code to solve the Navier-Stokes equation instead of Reynolds equation and using the measured data to validate the model, the fluid flow in the horizontal 2D cross-sections of the fracture network was simulated. Results show that local clogging leads to a significant reshaping of the flow velocity field and a reduction of the transport capacity of the entire system. The flow rate distribution is highly influenced by the fractures connected to the dominant flow channels, although local disturbances in velocity field are unlikely to spread over the whole network. Also, modeling results indicate that water flow in a fracture network, compared with that in a single fracture, is likely to transit into turbulence earlier under the same hydraulic gradient due to the influence of fracture intersections.

scholarly journals Numerics made easy: solving the Navier–Stokes equation for arbitrary channel cross-sections using Microsoft Excel

2016 ◽  
Vol 18 (3) ◽  
Author(s):  
Christiane Richter ◽  
Frederik Kotz ◽  
Stefan Giselbrecht ◽  
Dorothea Helmer ◽  
Bastian E. Rapp
Keyword(s):  
Stokes Equation ◽  
Cross Sections ◽  
Navier Stokes ◽  
Microsoft Excel ◽  
Navier Stokes Equation

Wall Pressure and Shear Stress Variations in a 90-Deg Bifurcation During Pulsatile Laminar Flow

1991 ◽  
Vol 113 (1) ◽  
pp. 111-115 ◽  
Author(s):  
J. M. Khodadadi
Keyword(s):  
Shear Stress ◽  
Laminar Flow ◽  
Wall Shear Stress ◽  
Cross Sections ◽  
Adverse Pressure Gradient ◽  
Wall Pressure ◽  
Navier Stokes ◽  
Shear Stresses ◽  
Navier Stokes Equation ◽  
Wall Shear

Wall pressure distribution and shear stress fields for pulsatile laminar flow in a 90-degree bifurcation with rectangular cross sections are evaluated using the results of the numerical solution of the Navier-Stokes equation. The extent of the adverse pressure gradient on the bottom wall of the main duct and the upstream wall of the branch closely correlate to the behavior of the two dynamic recirculation zones which are formed on these two walls. Multiple zones of high and low shear stresses at various sites in the bifurcation are observed. The extent of the fluctuations of the maximum and minimum shear stress is identified. Next-to-the-wall laser Doppler anemometer velocity measurements are used to estimate the shear stress distribution on the walls. In general, qualitative agreement between the experimental and computed wall shear stress values is observed. The variation of the wall shear stress in the vicinity of the branch is discussed in light of the highly perturbed flow field.

The Modeling and Flow Simulation of 40BZ6-15 Centrifugal Pump

2011 ◽  
Vol 317-319 ◽  
pp. 789-793
Author(s):  
Xiao Feng Shang ◽  
Liang Tong ◽  
Zhi Jian Wang
Keyword(s):  
Velocity Field ◽  
Centrifugal Pump ◽  
Pressure Field ◽  
Three Dimensional ◽  
Flow Simulation ◽  
Internal Flow ◽  
Navier Stokes ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Navier Stokes Equation

The three-Dimensional model of 40BZ6-15 centrifugal pump is built by the Solidworks software. This paper employs three-D Navier-Stokes equation and standard equation, and uses MRF and STMPLE algorithm to simulate the internal flowing of the 40BZ6 centrifugal pump. The velocity field and pressure field are gained. Through a further analysis, the rule of the internal flow of the centrifugal pump is unveiled, and then the simulative results are compared with the experimental ones, which can provide the base for the further improvement of the centrifugal pump.

Investigation into Fluid Velocity Field of Wedge-Shaped Gap in Grinding

2010 ◽  
Vol 37-38 ◽  
pp. 593-598 ◽  
Author(s):  
Chang He Li ◽  
Zhen Lu Han ◽  
Jing Yao Li
Keyword(s):  
Velocity Field ◽  
Fluid Velocity ◽  
Fluid Pressure ◽  
Surface Velocity ◽  
Navier Stokes ◽  
Coolant Fluid ◽  
Navier Stokes Equation ◽  
Part Surface ◽  
Peripheral Surface ◽  
Fluid Velocity Field

In the grinding process, grinding fluid is delivered for the purposes of chip flushing, cooling, lubrication and chemical protection of work surface. Hence, the conventional method of flood delivering coolant fluid by a nozzle in order to achieve high process performance purposivelly. However, hydrodynamic fluid pressure can be generated ahead of the grinding zone due to the wedge effect between wheel peripheral surface and part surface. In this paper, a theoretical fluid velocity field modeling is presented for flow of coolant fluid of wedge-shaped gap in flood delivery surface grinding, which is based on navier-stokes equation and continuous formulae. The numerical simulation results showed that the velocity in the x direction was dominant and the side-leakage in the y direction existed. The velocity in the z direction was smaller than the others because of the assumption of laminar flow. The smaller the gap is, the larger the velocity in the x direction. The magnitude of the velocity is also proportional to the surface velocity of the wheel.

scholarly journals Mathematic simulation of cutting unloading from the bunker

2019 ◽  
Vol 10 (7) ◽  
pp. 758 ◽  
Author(s):  
Serhii Yermakov ◽  
Taras Hutsol ◽  
Oleh Ovcharuk ◽  
Iryna Kolosiuk
Keyword(s):  
Differential Equation ◽  
Mathematical Model ◽  
Velocity Field ◽  
Boundary Conditions ◽  
Gaseous Medium ◽  
Navier Stokes ◽  
Bulk Materials ◽  
Navier Stokes Equation ◽  
Planting Material ◽  
The Mathematical Model

The peculiarities of cutting movement at unloading them from the hopper are described. The analysis of the scientific researches on bulk materials movement and bridging is given. To develop the mathematical model of cutting unloading the layer should be described as a pseudoliquid, that consists of discrete components (cuttings) and gaseous medium (air). The Navier-Stokes equation can be applied to the process of cutting unloading and velocity field. The equation of pseudoliquid motion is a nonlinear integral and differential equation. The initial and boundary conditions for speed of cutting movement are identified. As a result of research has been theoretically obtained a formula, that evaluates the rate of planting material unloading, the adequacy of which has already been partially tested in experimental experiments carried out by the authors on the way to creating an automatic planting machine.

Simulation Study of Thermal Buoyance Influence on Flow Characteristic in Single Outlet Tundish

2005 ◽  
Vol 475-479 ◽  
pp. 3215-3218
Author(s):  
Jun Fei Fan ◽  
Ya Xian Chen ◽  
San Bing Ren ◽  
Zong Ze Huang ◽  
Miao-yong Zhu
Keyword(s):  
Velocity Field ◽  
Numerical Solution ◽  
Stokes Equation ◽  
Excellent Agreement ◽  
Simulation Study ◽  
Flow Characteristic ◽  
Navier Stokes ◽  
Navier Stokes Equation ◽  
Flow Method ◽  
Computational Data

The distribution of velocity field in single outlet tundish has been simulated through numerical solution of turbulent Navier-Stokes equation in conjunction with e − k turbulence model. The theoretical predicted results have compared with experimental ones, and excellent agreement between them has been achieved. Through comparing the computational data using coupled heat and flow method with that of using uncoupled method, it indicated that it’s necessary to utility the coupled heat and flow method in big size tundish since the thermal buoyance should not be ignored in the calculation.

scholarly journals Numerical Study of Bloodstream Diffusion of the New Generation of Drug-Eluting Stents in Coronary Arteries

Fluids ◽  
2021 ◽  
Vol 6 (2) ◽  
pp. 71
Author(s):  
Leandro Marques ◽  
Gustavo R. Anjos
Keyword(s):  
Coronary Artery ◽  
Cross Sections ◽  
Numerical Study ◽  
Navier Stokes ◽  
Drug Eluting Stents ◽  
Drug Eluting Stent ◽  
Variable Cross ◽  
Navier Stokes Equation ◽  
Drug Eluting ◽  
New Generation

The present work aims at developing a numerical study on the drug diffusion in the bloodstream in a coronary artery with drug-eluting stent implanted. The blood was modeled as a single-phase, incompressible and Newtonian fluid and the Navier–Stokes equation was approximated according to the Finite Element Method (FEM). The dynamics of drug-eluting concentration in bloodstream was investigated using four drug-eluting stents with different mass diffusivities in microchannels with variable cross sections, including a real coronary artery geometry with atherosclerosis. The results reveal complex drug concentration patterns and accumulation in the vicinity of the fat buildup.

scholarly journals An Incompressible Polymer Fluid Interacting with a Koiter Shell

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Dominic Breit ◽  
Prince Romeo Mensah
Keyword(s):  
Moving Boundary ◽  
Classical Model ◽  
Elastic Shell ◽  
Planck Equation ◽  
Navier Stokes ◽  
Flexible Shell ◽  
Navier Stokes Equation ◽  
Shell System ◽  
Forward Equation ◽  
Polymer Fluid

AbstractWe study a mutually coupled mesoscopic-macroscopic-shell system of equations modeling a dilute incompressible polymer fluid which is evolving and interacting with a flexible shell of Koiter type. The polymer constitutes a solvent-solute mixture where the solvent is modelled on the macroscopic scale by the incompressible Navier–Stokes equation and the solute is modelled on the mesoscopic scale by a Fokker–Planck equation (Kolmogorov forward equation) for the probability density function of the bead-spring polymer chain configuration. This mixture interacts with a nonlinear elastic shell which serves as a moving boundary of the physical spatial domain of the polymer fluid. We use the classical model by Koiter to describe the shell movement which yields a fully nonlinear fourth order hyperbolic equation. Our main result is the existence of a weak solution to the underlying system which exists until the Koiter energy degenerates or the flexible shell approaches a self-intersection.

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