scholarly journals Finite Element Simulation of Newtonian and Non-Newtonian Fluid through the Parallel Plates Affixed with Single Screen

2020 ◽  
Vol 13 (1) ◽  
pp. 69-83
Author(s):  
Abid Ali Memon ◽  
Muhammad Asif Memon ◽  
Kaleemullah Bhatti ◽  
Gul Muhammad Shaikh
Keyword(s):  
Reynolds Number ◽  
Finite Element ◽  
Newtonian Fluid ◽  
Flow Rate ◽  
Rectangular Channel ◽  
Maximum Flow ◽  
Least Square ◽  
Maximum Flow Rate ◽  
Parallel Plates ◽  
The Impact

In the contemporary research article we have performed a numerical investigation of the non-Newtonian fluid flow through a rectangular channel with a fixed solid screen devoted at the angles 100 to 450 degrees. We have employed the power-law model for shear thickening and shear thinning fluids with the high Reynolds number between 1000 and 10,000. The obstacle has been solved by putting in the Galerkin’s least square strategy of the finite element method and the procedure has been carried out utilizing the commercial software COMSOL Multiphysics. Various flow properties such as 'maximum flow rate' and 'pressure' have been discussed in the terms of the Reynolds number and also using the linear and quadratic regressions in order to establish the relationship between them for the future analysis. Moreover the impact of turning screen in the shape of increment in the maximum flow rate and pressure is checked in terms of Reynolds number and  Satisfactory results are gained in comparison with the results available in the literature.

scholarly journals Finite Element Simulation of Newtonian and Non-Newtonian Fluid through the Parallel Plates Affixed with Single Screen

2020 ◽  
Vol 13 (1) ◽  
pp. 69-83
Author(s):  
Abid Ali Memon ◽  
Muhammad Asif Memon ◽  
Kaleemullah Bhatti ◽  
Gul Muhammad Shaikh
Keyword(s):  
Reynolds Number ◽  
Finite Element ◽  
Newtonian Fluid ◽  
Flow Rate ◽  
Rectangular Channel ◽  
Maximum Flow ◽  
Least Square ◽  
Maximum Flow Rate ◽  
Parallel Plates ◽  
The Impact

In the contemporary research article we have performed a numerical investigation of the non-Newtonian fluid flow through a rectangular channel with a fixed solid screen devoted at the angles 100 to 450 degrees. We have employed the power-law model for shear thickening and shear thinning fluids with the high Reynolds number between 1000 and 10,000. The obstacle has been solved by putting in the Galerkin’s least square strategy of the finite element method and the procedure has been carried out utilizing the commercial software COMSOL Multiphysics. Various flow properties such as 'maximum flow rate' and 'pressure' have been discussed in the terms of the Reynolds number and also using the linear and quadratic regressions in order to establish the relationship between them for the future analysis. Moreover the impact of turning screen in the shape of increment in the maximum flow rate and pressure is checked in terms of Reynolds number and  Satisfactory results are gained in comparison with the results available in the literature.

scholarly journals Vibroextrusion flow of concrete mixtures in a right four-corner pyramidal channel

2021 ◽  
pp. 9-15
Author(s):  
Igor Andreiev ◽  
Andrey Pinchuk ◽  
Oleksandra Kramar
Keyword(s):  
Cross Section ◽  
Newtonian Fluid ◽  
Flow Rate ◽  
Rectangular Cross Section ◽  
Rectangular Channel ◽  
Maximum Flow ◽  
Fiber Reinforced Concrete ◽  
Concrete Mixture ◽  
Parallel Plates ◽  
Concrete Mixtures

The purpose of the research was to obtain calculation formulas for describing the flow of concrete mixtures and determining their viscosity directly in the process of vibroextrusion in regular quadrangular pyramidal channels. In solving the flow problems, it was taken into account that concrete mixtures are non-Newtonian systems in the conditions of a vibration field, and hydrodynamic theories were used to calculate the processes and rheological characteristics. Since the calculation formulas for describing the flow of fluids in a regular quadrangular pyramidal channel are absent and the channel has a square cross section, an analytical dependence was used to characterize the process, which describes the flow of a Newtonian fluid in a rectangular channel of constant cross section. The authors proposed for use simplified formulas for determining the maximum flow rate and flow rate of a Newtonian fluid in a channel of rectangular cross-section. The degree of decrease in the flow velocity and the flow rates of a Newtonian fluid in a channel of rectangular cross-section in comparison with the flow between flat parallel plates are analyzed. To describe the flow of concrete mixtures in regular quadrangular pyramidal channels, the proposed coefficients for reducing the speed and flow rate, as well as the existing formulas for the flow between flat symmetric stationary walls, which converge, were used. The possibility of using the obtained formula for the flow rate in a regular quadrangular pyramidal channel for calculating the viscosity of a concrete mixture during vibration extrusion is shown. To simplify the experimental procedure, a new formula for calculating the viscosity based on the expiration time for a certain amount of concrete mixture has been proposed. The formulas obtained are convenient for further mathematical processing and have no restrictions in their application. The proposed method for determining the viscosity expands the possibilities of studying the rheological properties of concrete mixtures in the vibroextrusion of fiber-reinforced concrete mixtures.

scholarly journals Finite Element Least Square Technique for Newtonian Fluid Flow through a Semicircular Cylinder of Recirculating Region via COMSOL Multiphysics

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Ilyas Khan ◽  
Abid A. Memon ◽  
M. Asif Memon ◽  
Kaleemullah Bhatti ◽  
Gul M. Shaikh ◽  
...  
Keyword(s):  
Reynolds Number ◽  
Fluid Flow ◽  
Newtonian Fluid ◽  
Rectangular Channel ◽  
Numerical Procedure ◽  
Least Square ◽  
Comsol Multiphysics ◽  
Velocity Magnitude ◽  
Increase Reynolds Number ◽  
Flow Through

This article aims to study Newtonian fluid flow modeling and simulation through a rectangular channel embedded in a semicircular cylinder with the range of Reynolds number from 100 to 1500. The fluid is considered as laminar and Newtonian, and the problem is time independent. A numerical procedure of finite element’s least Square technique is implemented through COMSOL multiphysics 5.4. The problem is validated through asymptotic solution governed through the screen boundary condition. The vortex length of the recirculating region formed at the back of the cylinder and orientation of velocity field and pressure will be discussed by three horizontal and four vertical lines along the recirculating region in terms of Reynolds number. It was found that the two vortices of unequal size have appeared and the lengths of these vortices are increased with the increase Reynolds number. Also, the empirical equations through the linear regression procedure were determined for those vortices. The orientation of the velocity magnitude as well as pressure along the lines passing through the center of upper and lower vortices are the same.

The Impact of Emergency Release in LNG Transfer

2014 ◽  
Author(s):  
Evert van Bokhorst ◽  
Tony Webber ◽  
Jesper van der Putte ◽  
Jan Smeulers ◽  
David Remans
Keyword(s):  
Flow Rate ◽  
Propagation Speed ◽  
Maximum Flow ◽  
Maximum Flow Rate ◽  
Shock Loads ◽  
Acoustic Damping ◽  
Pressure Transients ◽  
Flow Test ◽  
Pressure Surge ◽  
The Impact

This paper describes the results of experimental work and simulations of pressure surges resulting from fast closing valves and activation of an emergency release coupling (ERC) in ship-to-ship LNG transfer. The first part presents the results of an ambient water flow test with a fast closing 4-inch full bore valve in combination with a 4-inch flexible multi-composite hose. High amplitude pressure surges up to 4 times the working pressure occur upstream of the valve. Pressure surge amplitudes strongly depend on valve closing time and flow rate. The propagation speed in the upstream hose is lowered considerably due to the hose flexibility. Furthermore the temporarily deformation of the hose results in loss of energy and acoustic damping of the pressure surge amplitudes. The measurement results are compared to the results of modeling. Acoustic damping and propagation speed of sound show a non-linear behavior of the hose, due to a varying internal pressure, which is not captured in the present modeling techniques. The second part of the paper describes the results of a full scale flow test on an 8-inch ERC (KLAW make) for LNG ship-to-ship transfer (Figure 1). The ERC in the test is located downstream of an 8-inch 15-meter long multi-composite flexible hose. The test is intended to investigate operational and mechanical integrity, spill rate and the impact of pressure transients and shock loads on the ERC including upstream hose and downstream piping. Upon hydraulic activation the ERC separates in two parts, each provided with a fast closing butterfly valve. The complete operation takes about 0.2 s and the actual valve closure duration is about 0.02 s resulting in a negligible spill of less than 0.002 m3. Pressure transients from 34 to 100 bar, over 10 times the operating pressure, occur at the maximum flow rate of 1000 m3/hr, resulting in shock loads and high acceleration levels. The mechanical integrity remains intact even after four successive releases at the maximum flow rate of 1000 m3/hr. The results contribute to the certification of the ERC by Lloyds B.V. Further development in modeling is necessary to obtain a validated model for the calculation of pressure surges due to emergency shutdown in a LNG transfer.

Steady Flow Hemodynamic and Energy Loss Measurements in Normal and Simulated Calcified Tricuspid and Bicuspid Aortic Valves

2014 ◽  
Vol 136 (4) ◽  
Author(s):  
Clara Seaman ◽  
A. George Akingba ◽  
Philippe Sucosky
Keyword(s):  
Pressure Drop ◽  
Aortic Valve ◽  
Energy Loss ◽  
Steady Flow ◽  
Flow Rate ◽  
Maximum Flow ◽  
Maximum Flow Rate ◽  
Type I ◽  
Orifice Area ◽  
The Impact

The bicuspid aortic valve (BAV), which forms with two leaflets instead of three as in the normal tricuspid aortic valve (TAV), is associated with a spectrum of secondary valvulopathies and aortopathies potentially triggered by hemodynamic abnormalities. While studies have demonstrated an intrinsic degree of stenosis and the existence of a skewed orifice jet in the BAV, the impact of those abnormalities on BAV hemodynamic performance and energy loss has not been examined. This steady-flow study presents the comparative in vitro assessment of the flow field and energy loss in a TAV and type-I BAV under normal and simulated calcified states. Particle-image velocimetry (PIV) measurements were performed to quantify velocity, vorticity, viscous, and Reynolds shear stress fields in normal and simulated calcified porcine TAV and BAV models at six flow rates spanning the systolic phase. The BAV model was created by suturing the two coronary leaflets of a porcine TAV. Calcification was simulated via deposition of glue beads in the base of the leaflets. Valvular performance was characterized in terms of geometric orifice area (GOA), pressure drop, effective orifice area (EOA), energy loss (EL), and energy loss index (ELI). The BAV generated an elliptical orifice and a jet skewed toward the noncoronary leaflet. In contrast, the TAV featured a circular orifice and a jet aligned along the valve long axis. While the BAV exhibited an intrinsic degree of stenosis (18% increase in maximum jet velocity and 7% decrease in EOA relative to the TAV at the maximum flow rate), it generated only a 3% increase in EL and its average ELI (2.10 cm2/m2) remained above the clinical threshold characterizing severe aortic stenosis. The presence of simulated calcific lesions normalized the alignment of the BAV jet and resulted in the loss of jet axisymmetry in the TAV. It also amplified the degree of stenosis in the TAV and BAV, as indicated by the 342% and 404% increase in EL, 70% and 51% reduction in ELI and 48% and 51% decrease in EOA, respectively, relative to the nontreated valve models at the maximum flow rate. This study indicates the ability of the BAV to function as a TAV despite its intrinsic degree of stenosis and suggests the weak dependence of pressure drop on orifice area in calcified valves.

scholarly journals Finite Element Analysis of Fluid Flow through the Screen Embedded between Parallel Plates with High Reynolds Numbers

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Abid A. Memon ◽  
Hammad Alotaibi ◽  
M. Asif Memon ◽  
Kaleemullah Bhatti ◽  
Gul M. Shaikh ◽  
...  
Keyword(s):  
Reynolds Number ◽  
Fluid Flow ◽  
Stokes Equations ◽  
Rectangular Channel ◽  
General Pattern ◽  
Resistance Coefficient ◽  
Least Square ◽  
Final Conclusion ◽  
Linear Regression Method ◽  
Parallel Plates

This paper provides numerical estimation of Newtonian fluid flow past through rectangular channel fixed with screen movable from 10° to 45° by increasing the Reynolds number from 1000 to 10,000. The two-dimensional incompressible Navier Stokes equations are worked out making use of the popular software COMSOL MultiPhysics version 5.4 which implements the Galerkin’s least square scheme to discretize the governing set of equations into algebraic form. In addition, the screen boundary condition with resistance coefficient (2.2) along with resistance coefficient 0.78 is implemented along with slip boundary conditions applied on the wall. We engaged to find and observe the relationship between the optimum velocity, drag force applied by the screen, and pressure occurred in the channel with increasing Reynolds number. Because of the linear relationship between the optimum velocities and the Reynolds number, applying the linear regression method, we will estimate the linear equation so that future prediction and judgment can be done. The validity of results is doing with the asymptomatic solution for stream-wise velocity at the outlet of the channel with screens available in the literature. A nondimensional quantity, i.e., ratio from local to global Reynolds number Re x / Re , is introduced which found stable and varies from -0.5 to 0.5 for the whole problem. Thus, we are in the position to express the general pattern of the velocity of the particles as well as the pressure on the line passing through the middle of the channel and depart some final conclusion at the end.

Lichen sclerosis–induced long segment anterior urethral stricture: The early outcome of one-stage repair using dorsolateral onlay buccal mucosa graft

2021 ◽  
pp. 039156032110033
Author(s):  
Atef Fathi ◽  
Omar Mohamed ◽  
Osama Mahmoud ◽  
Gamal A Alsagheer ◽  
Ahmed M Reyad ◽  
...  
Keyword(s):  
Success Rate ◽  
Urethral Stricture ◽  
Flow Rate ◽  
Urine Volume ◽  
Maximum Flow ◽  
Maximum Flow Rate ◽  
P Value ◽  
Onlay Graft ◽  
Voiding Symptoms ◽  
Stricture Recurrence

Background: Substitution urethroplasty using buccal mucosal grafts can be performed by several approaches including ventral onlay graft, dorsal onlay graft, or ventral urethrotomy with dorsal inlay graft. Our study aims to evaluate the surgical outcome of dorsolateral buccal mucosal graft for long segment anterior urethral stricture >6 cm in patients with Lichen sclerosus (LS). Methods: A retrospective study included patients who underwent repair for long segment anterior urethral stricture >6 cm due to LS between January 2013 and April 2019. All patients were followed-up at 3, 6, 9, and 12 months postoperatively and then yearly by clinical symptoms, uroflowmetry, and calculation of post-void residual urine volume. Retrograde urethrogram was requested for patients with voiding symptoms or decreased maximum flow rate. Stricture recurrence that required subsequent urethrotomy or urethroplasty was considered failure. The success rate and surgical complications were collected and analyzed. Results: Thirty patients were identified. The median age (range) was 39 (25–61) years and a median (range) stricture length was 8 (6–14) cm. Most of postoperative complications were of minor degree. The success rate at median follow-up of 15 (12–24) months was 86.5%. The median maximum flow rate increased significantly from 6 (2–11) ml/s preoperatively to 18 (range: 6–23) ml/s at the 6th month ( p value < 0.001). Conclusion: Dorsolateral buccal mucosal grafts urethroplasty for long anterior urethral stricture caused by LS has a high success rate and low risk of complications including stricture recurrence.

scholarly journals Maximum Flow Rate of a Single Component, Two-Phase Mixture

1965 ◽  
Vol 87 (1) ◽  
pp. 134-141 ◽  
Author(s):  
F. J. Moody
Keyword(s):  
Flow Rate ◽  
Static Pressure ◽  
Maximum Flow ◽  
Single Component ◽  
Maximum Flow Rate ◽  
Vapor Flow ◽  
Two Phase ◽  
Slip Ratio ◽  
Phase Mixture ◽  
Local Slip

A theoretical model is developed for predicting the maximum flow rate of a single component, two-phase mixture. It is based upon annular flow, uniform linear velocities of each phase, and equilibrium between liquid and vapor. Flow rate is maximized with respect to local slip ratio and static pressure for known stagnation conditions. Graphs are presented giving maximum steam/water flow rates for: local static pressures between 25 and 3,000 psia, with local qualities from 0.01 to 1.00; local stagnation pressures and enthalpies which cover the range of saturation states.

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