scholarly journals Shear-Thinning Fluid Flow in Variable-Aperture Channels

Water ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 1152 ◽  
Author(s):  
Alessandro Lenci ◽  
Sandro Longo ◽  
Vittorio Di Federico
Keyword(s):  
Fluid Flow ◽  
Pressure Gradient ◽  
Flow Rate ◽  
Shear Thinning ◽  
Skewed Distribution ◽  
Upper And Lower Bounds ◽  
Single Fracture ◽  
Nonlinear Phenomenon ◽  
Hydraulic Aperture ◽  
Fluid Rheology

Non-Newtonian fluid flow in a single fracture is a 3-D nonlinear phenomenon that is often averaged across the fracture aperture and described as 2-D. To capture the key interactions between fluid rheology and spatial heterogeneity, we adopt a simplified geometric model to describe the aperture variability, consisting of adjacent one-dimensional channels with constant aperture, each drawn from an assigned aperture distribution. The flow rate is then derived under the lubrication approximation for the two limiting cases of an external pressure gradient that is parallel/perpendicular to the channels; these two arrangements provide upper and lower bounds to the fracture conductance. The fluid rheology is described by the Prandtl–Eyring shear-thinning model. Novel closed-form results for the flow rate and hydraulic aperture are derived and discussed; different combinations of the parameters that describe the fluid rheology and the variability of the aperture field are considered. The flow rate values are very sensitive to the applied pressure gradient and to the shape of the distribution; in particular, more skewed distribution entails larger values of a dimensionless flow rate. Results for practical applications are compared with those valid for a power-law fluid and show the effects on the fracture flow rate of a shear stress plateau.

scholarly journals Shear-Thinning Fluid Flow in Variable-Aperture Channels

Proceedings ◽  
2019 ◽  
Vol 48 (1) ◽  
pp. 28
Author(s):  
Alessandro Lenci ◽  
Vittorio Di Federico
Keyword(s):  
Fluid Flow ◽  
Pressure Gradient ◽  
Flow Rate ◽  
Geometric Model ◽  
Shear Thinning ◽  
Single Fracture ◽  
Fracture Aperture ◽  
Nonlinear Phenomenon ◽  
Hydraulic Aperture ◽  
Fluid Rheology

Non-Newtonian fluid flow in a single fracture is a 3D nonlinear phenomenon that is often averaged across the fracture aperture and described as 2D. To capture key interactions between fluid rheology and spatial heterogeneity, we adopted a simplified geometric model to describe aperture variability, consisting of adjacent one-dimensional channels with constant aperture, each drawn from assigned aperture distribution. The flow rate was then derived under the lubrication approximation for the two limiting cases of an external pressure gradient that was parallel/perpendicular to the channels; these two arrangements provided an upper/lower bound to fracture conductance. Fluid rheology was described via the Prandtl–Eyring shear-thinning model. Novel closed-form results for flow rate and hydraulic aperture were derived and are discussed; different combinations of parameters describing the fluid rheology and variability of the aperture field were considered. In general, flow rate depends, in a nonlinear fashion, on the dimensionless pressure gradient and distribution parameters.

scholarly journals Analysis of Fracture Roughness Control on Permeability Using SfM and Fluid Flow Simulations: Implications for Carbonate Reservoir Characterization

Geofluids ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-19 ◽  
Author(s):  
Miller Zambrano ◽  
Alan D. Pitts ◽  
Ali Salama ◽  
Tiziano Volatili ◽  
Maurizio Giorgioni ◽  
...  
Keyword(s):  
Fluid Flow ◽  
Reservoir Characterization ◽  
Flow Simulation ◽  
Carbonate Reservoir ◽  
Single Fracture ◽  
Parallel Plates ◽  
Surface Mapping ◽  
Navier Stokes Equation ◽  
Hydraulic Aperture ◽  
Fracture Modeling

Fluid flow through a single fracture is traditionally described by the cubic law, which is derived from the Navier-Stokes equation for the flow of an incompressible fluid between two smooth-parallel plates. Thus, the permeability of a single fracture depends only on the so-called hydraulic aperture which differs from the mechanical aperture (separation between the two fracture wall surfaces). This difference is mainly related to the roughness of the fracture walls, which has been evaluated in previous works by including a friction factor in the permeability equation or directly deriving the hydraulic aperture. However, these methodologies may lack adequate precision to provide valid results. This work presents a complete protocol for fracture surface mapping, roughness evaluation, fracture modeling, fluid flow simulation, and permeability estimation of individual fracture (open or sheared joint/pressure solution seam). The methodology includes laboratory-based high-resolution structure from motion (SfM) photogrammetry of fracture surfaces, power spectral density (PSD) surface evaluation, synthetic fracture modeling, and fluid flow simulation using the Lattice-Boltzmann method. This work evaluates the respective controls on permeability exerted by the fracture displacement (perpendicular and parallel to the fracture walls), surface roughness, and surface pair mismatch. The results may contribute to defining a more accurate equation of hydraulic aperture and permeability of single fractures, which represents a pillar for the modeling and upscaling of the hydraulic properties of a geofluid reservoir.

Fluid Flow and Solute Transport though a Fracture Intersecting a Canister - Analytical Solutions for the Parallel Plate Model

2003 ◽  
Vol 807 ◽  
Author(s):  
L. Liu ◽  
I. Neretnieks
Keyword(s):  
Fluid Flow ◽  
Solute Transport ◽  
Flow Rate ◽  
Analytical Solutions ◽  
Parallel Plate ◽  
Spent Nuclear Fuel ◽  
Volumetric Flow Rate ◽  
Single Fracture ◽  
Plate Model ◽  
Specific Scenario

ABSTRACTIn this paper, we are concerned with a specific scenario where a large fracture intersects, at its center, a canister that contains spent nuclear fuel. Assuming that a nuclide is free to release from the canister into groundwater flowing through the fracture, a detailed formulation of the volumetric flow rate and the equivalent flow rate are made for the parallel plate model. The formulas proposed have been validated by numerical examinations; they are not only simple in forms but also universal in applications where the flow may be taken normal, inclined or parallel to the axis of the canister. Of great importance, they provide a convenient way to predict the average properties of fluid flow and solute transport through a single fracture with spatially variable apertures.

Pulsatile flow in rigid tubes

1965 ◽  
Vol 20 (5) ◽  
pp. 1078-1082 ◽  
Author(s):  
Robert G. Linford ◽  
Norman W. Ryan
Keyword(s):  
Fluid Flow ◽  
Pressure Gradient ◽  
Flow Rate ◽  
Pulsatile Flow ◽  
Fluid Velocity ◽  
Fluid Flow Rate ◽  
Tube Radius ◽  
Low Frequencies ◽  
Time Relationship ◽  
Fluid Properties

The purpose of this study was to examine critically the theoretical equations derived for pulsatile laminar flow in rigid straight tubes. These equations, presented in their most useful form by J. R. Womersley in 1955, give the fluid flow rate as a function of the pressure gradient-time relationship, pulse frequency, fluid properties, and tube radius, and they give the fluid velocity as a function of the above quantities and the radial position in the tube. A pulsatile flow apparatus was constructed which would allow measurement of all the variables mentioned above, and a computer program based on Womersley's equations was used to calculate the fluid flow rate and velocity profile from the pressure gradient-time relationship, fluid properties, and tube radius. Thus a comparison between measured and calculated values of flow and velocity could be made. Calculations and data agree within the estimated experimental error, thus providing evidence of the applicability of the theoretical equations to actual flow with large pulse amplitudes. The analog computer “pressure gradient technique” of D. Fry and associates was compared with the exact solution for straight rigid tubes and found to deviate less than 20% in amplitude and phase except at very low frequencies. hydrodynamics, pulsatile flow; blood flow, arterial; hemodynamics, pulse characteristics Submitted on April 6, 1964

scholarly journals Prospects of High Viscosity Oil Flow Rate in Horizontal Wells

2021 ◽  
Author(s):  
Sudad H Al-Obaidi ◽  
Galkin AP ◽  
Patkin AA
Keyword(s):  
Fluid Flow ◽  
Pressure Gradient ◽  
Flow Rate ◽  
Pore Space ◽  
Analytical Formula ◽  
High Viscosity ◽  
Pressure Gradients ◽  
Oil Flow ◽  
Molecular Components ◽  
High Viscosity Oil

The non-Newtonian nature of fluid flow represents one of the most important features of the development of high-viscosity oil (HVO) deposits .The deviation from the linear law of the fluid flow is associated, first of all, with the formation of a strong spatial structure due to the presence of high-molecular components and dissolved gases in the composition. The stress required to destroy the formed structure is called the shear stress of the ultimate destruction of the structure. In this regard, in order to ensure the flow of HVO through the pore space, it is necessary to create certain values of pressure gradients above the dynamic shear pressure gradient (DSPG). With increasing pressure gradients above the DSPG, the oil structure begins to collapse, and after overcoming the critical value of the pressure gradient of the ultimate destruction of the structure (PGUDS), flow begins to be described by the Newtonianlaw. The article considers the influence of various factors on the oil flow rate of a horizontal well (HW) that exploits the HVO Deposit. At the same time, numerical experiments were carried out on a hydrodynamic model for the non-Newtonian oil flow regime (in the presence of DSPG) and the results obtained were compared with calculations of the oil flow rate using an analytical formula.

Influence of Non-Newtonian Behavior of Blood on Flow in an Elastic Artery Model

1996 ◽  
Vol 118 (1) ◽  
pp. 111-119 ◽  
Author(s):  
A. Dutta ◽  
J. M. Tarbell
Keyword(s):  
Shear Stress ◽  
Pressure Gradient ◽  
Power Law ◽  
Flow Rate ◽  
Wall Motion ◽  
Flow Simulation ◽  
Shear Thinning ◽  
Power Law Model ◽  
Viscous Shear ◽  
Sinusoidal Flow

Two different non-Newtonian models for blood, one a simple power law model exhibiting shear thinning viscosity, and another a generalized Maxwell model displaying both shear thining viscosity and oscillatory flow viscoelasticity, were used along with a Newtonian model to simulate sinusoidal flow of blood in rigid and elastic straight arteries. When the spring elements were removed from the viscoelastic model resulting in a purely viscous shear thinning fluid, the predictions of flow rate and WSS were virtually unaltered. Hence, elasticity of blood does not appear to influence its flow behavior under physiological conditions in large arteries, and a purely viscous shear thinning model should be quite realistic for simulating blood flow under these conditions. When a power law model with a high shear rate Newtonian cutoff was used for sinusoidal flow simulation in elastic arteries, the mean and amplitude of the flow rate were found to be lower for a power law fluid compared to a Newtonian fluid experiencing the same pressure gradient. The wall shear stress was found to be relatively insensitive to fluid rheology but strongly dependent on vessel wall motion for flows driven by the same pressure gradient. The effect of wall motion on wall shear stress could be greatly reduced by matching flow rate rather than pressure gradient. For physiological flow simulation in the aorta, an increase in mean WSS but a reduction in peak WSS were observed for the power law model compared to a Newtonian fluid model for a matched flow rate waveform.

Application of Cross-correlation Analysis Method for Measurement of the Fluid Flow Rate Based on X-ray Radiation

2019 ◽  
Vol 11 (1) ◽  
pp. 01025-1-01025-5 ◽  
Author(s):  
N. A. Borodulya ◽  
◽  
R. O. Rezaev ◽  
S. G. Chistyakov ◽  
E. I. Smirnova ◽  
...  
Keyword(s):  
Fluid Flow ◽  
Correlation Analysis ◽  
Flow Rate ◽  
Cross Correlation ◽  
Fluid Flow Rate ◽  
Analysis Method ◽  
X Ray ◽  
Cross Correlation Analysis ◽  
Correlation Analysis Method

Study of fluid flow through a channel deformed by piezoelement

2018 ◽  
Vol 13 (3) ◽  
pp. 1-10 ◽  
Author(s):  
I.Sh. Nasibullayev ◽  
E.Sh Nasibullaeva ◽  
O.V. Darintsev
Keyword(s):  
Fluid Flow ◽  
Pressure Drop ◽  
Boundary Conditions ◽  
Flow Rate ◽  
Contact Surface ◽  
Piezoelectric Element ◽  
Neumann Boundary ◽  
Differential Pressure ◽  
Physical Parameters ◽  
Flow Through

The flow of a liquid through a tube deformed by a piezoelectric cell under a harmonic law is studied in this paper. Linear deformations are compared for the Dirichlet and Neumann boundary conditions on the contact surface of the tube and piezoelectric element. The flow of fluid through a deformed channel for two flow regimes is investigated: in a tube with one closed end due to deformation of the tube; for a tube with two open ends due to deformation of the tube and the differential pressure applied to the channel. The flow rate of the liquid is calculated as a function of the frequency of the deformations, the pressure drop and the physical parameters of the liquid.

Flow Features Analysis of Throttle Notches of Proportional Direct Valve

2011 ◽  
Vol 189-193 ◽  
pp. 2285-2288
Author(s):  
Wen Hua Jia ◽  
Chen Bo Yin ◽  
Guo Jin Jiang
Keyword(s):  
Fluid Flow ◽  
Dynamic Behavior ◽  
Flow Rate ◽  
Discharge Coefficient ◽  
3D Models ◽  
Operating Conditions ◽  
Flow Models ◽  
Flow Features ◽  
Rate Discharge ◽  
Spool Valve

Flow features, specially, flow rate, discharge coefficient and efflux angle under different operating conditions are numerically simulated, and the effects of shapes and the number of notches on them are analyzed. To simulate flow features, 3D models are developed as commercially available fluid flow models. Most construction machineries in different conditions require different actions. Thus, in order to be capable of different actions and exhibit good dynamic behavior, flow features should be achieved in designing an optimized proportional directional spool valve.

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