scholarly journals Experimental and Numerical Study on the Permeation Grouting Diffusion Mechanism considering Filtration Effects

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Guangxuan Zhu ◽  
Qingsong Zhang ◽  
Rentai Liu ◽  
Jiwen Bai ◽  
Wei Li ◽  
...  
Keyword(s):  
Rheological Behavior ◽  
Numerical Solutions ◽  
Numerical Study ◽  
Diffusion Mechanism ◽  
Experimental Results ◽  
Flow In Porous Media ◽  
Rheological Parameters ◽  
Permeation Grouting ◽  
Constant Flow Rate ◽  
Comparative Results

Permeation grouting estimation is important for the design of grouting engineering. Filtration effects and rheological behavior play a key role in permeation grouting diffusion of cement-based grouts. To better understand the effect of filtration and grout rheological behavior on the grouting diffusion mechanism, one-dimensional permeation grout injections in sand columns under constant flow rate were performed by a self-developed experimental procedure. Experimental results showed that there were dramatic variations in rheological parameters and porosity along the diffusion distance. However, the rheological parameters changed slightly with time for each position. Based on the experimental results, a numerical model considering the filtration effect and grout rheological behavior was established to describe the mechanism of grout flow in porous media. In addition, numerical solutions from the proposed model are compared with the experimental results. The comparative results showed that the proposed numerical method can match the laboratory tests well. Finally, the effects of the grout flow velocity and the water/cement ratio of the grout on the diffusion mechanism are also discussed.

scholarly journals Determination of Rheological Parameters from Measurements on a Viscometer with Coaxial Cylinders – Choice of the Reference Radius

10.14311/892 ◽  
2006 ◽  
Vol 46 (6) ◽  
Author(s):  
F. Rieger
Keyword(s):  
Experimental Data ◽  
Power Law ◽  
Rheological Behavior ◽  
Experimental Results ◽  
Rheological Parameters ◽  
Concentrated Suspensions ◽  
Rotational Viscometer ◽  
Coaxial Cylinders

Knowledge about rheological behavior is necessary in engineering calculations for equipment used for processing concentrated suspensions and polymers. Power-law and Bingham models are often used for evaluating the experimental data. This paper proposes the reference radius to which experimental results obtained by measurements on a rotational viscometer with coaxial cylinders should be related. 

scholarly journals CFD Characterization of a Wet Foam Flow Rheological Behavior

2018 ◽  
Author(s):  
Heni Dallagi ◽  
Ramla Gheith ◽  
Ahmad Al Saabi ◽  
Christine Faille ◽  
Wolfgang Augustin ◽  
...  
Keyword(s):  
Void Fraction ◽  
Rheological Behavior ◽  
Numerical Study ◽  
Rheological Parameters ◽  
Pressure Losses ◽  
Foam Flow ◽  
Robust Model ◽  
Image Velocimetry ◽  
Aqueous Foams ◽  
Reverse Method

In some industrial processes, aqueous foams flow presents an important phase of the process, whereas, they cause pressure drop when designing and dimensioning systems. Identifying the different rheological parameters of foam flow is an interest key to understanding the interfacial phenomena. Actually, the difficulty to model the rheological parameters of foam flow is a major challenge. In this study, we present a robust model to describe the foam fluid inside horizontal channels by the reverse approach of a numerical simulation (Computational Fluid Dynamics: CFD), based on the behavior laws of the Herschel-Bulkley type, for the non-Newtonian fluids. This reverse method starts from experimental (deduced from Particle Image Velocimetry (PIV) technique) results of the previous experimental work of Chovet (2015). The pressure losses measurements near-wall velocity fields, velocity profiles and the wall shear stress evolution including the void fraction from 55% to 85%, are considered in order to identify the different parameters of the developed model to determine the nature of the flow, the foams rheological behavior and the foam flow regime along the length of the channel. The numerical study (CFD) is applied for two conditions: the first one for a wet foam flow with a void fraction of 70% and a foam flow velocity of 2cm/s (one-dimensional regime) and the second one, for a foam quality of 55% and a flow rate of 6cm/s. The numerical evolutions are identical to experimental ones for these same conditions. Therefore, we can conclude that the Herschel-Bulkley rheological model can correctly describe the aqueous foams fix behavior.

Study of the Rheological Parameters of Honey Using the Mitschka Method

2009 ◽  
Vol 5 (3) ◽  
Author(s):  
Charles Windson Isidoro Haminiuk ◽  
Giselle M. Maciel ◽  
Manuel Salvador Vicente Plata-Oviedo ◽  
Alessandra Quenehenn ◽  
Agnes P Scheer
Keyword(s):  
Quality Control ◽  
Shear Stress ◽  
Shear Rate ◽  
Temperature Effect ◽  
Rheological Behavior ◽  
Food Industry ◽  
Experimental Results ◽  
Rheological Parameters ◽  
Quality Control Testing ◽  
Newtonian Behavior

In this work the rheological behavior of two varieties of honey were evaluated using a Brookfield viscometer R.V.T in a temperature range of 5-20°C. In order to interpret the experimental results in terms of viscosity, the torque-speed data and scale readings were converted into shear stress-shear rate relations using numerical conversion values proposed by Mitschka. This method offers excellent potential for quality control testing in the food industry. Samples exhibited Newtonian behavior and the temperature effect on the viscosity followed an Arrhenius-type relationship.

scholarly journals Is contact angle a cause or an effect? – A cautionary tale

2020 ◽  
Vol 146 ◽  
pp. 03004
Author(s):  
Douglas Ruth
Keyword(s):  
Contact Angle ◽  
Solid Surface ◽  
Contact Angles ◽  
Two Dimensions ◽  
Experimental Results ◽  
Flow In Porous Media ◽  
Two Dimensional ◽  
Wide Range ◽  
Fluid Drop ◽  
Surrounding Fluid

The most influential parameter on the behavior of two-component flow in porous media is “wettability”. When wettability is being characterized, the most frequently used parameter is the “contact angle”. When a fluid-drop is placed on a solid surface, in the presence of a second, surrounding fluid, the fluid-fluid surface contacts the solid-surface at an angle that is typically measured through the fluid-drop. If this angle is less than 90°, the fluid in the drop is said to “wet” the surface. If this angle is greater than 90°, the surrounding fluid is said to “wet” the surface. This definition is universally accepted and appears to be scientifically justifiable, at least for a static situation where the solid surface is horizontal. Recently, this concept has been extended to characterize wettability in non-static situations using high-resolution, two-dimensional digital images of multi-component systems. Using simple thought experiments and published experimental results, many of them decades old, it will be demonstrated that contact angles are not primary parameters – their values depend on many other parameters. Using these arguments, it will be demonstrated that contact angles are not the cause of wettability behavior but the effect of wettability behavior and other parameters. The result of this is that the contact angle cannot be used as a primary indicator of wettability except in very restricted situations. Furthermore, it will be demonstrated that even for the simple case of a capillary interface in a vertical tube, attempting to use simply a two-dimensional image to determine the contact angle can result in a wide range of measured values. This observation is consistent with some published experimental results. It follows that contact angles measured in two-dimensions cannot be trusted to provide accurate values and these values should not be used to characterize the wettability of the system.

Effects of Wind on the Heat Flow of FPSO Topsides Subject to Fire: An Experimental and Numerical Study

2010 ◽  
Author(s):  
Joon Young Yoon ◽  
Seong Hwan Kim ◽  
Gwon Cheol Yu ◽  
Jung Kwan Seo ◽  
Bong Ju Kim ◽  
...  
Keyword(s):  
Thermal Diffusion ◽  
Numerical Study ◽  
Wind Tunnel Test ◽  
Experimental Results ◽  
Test Facility ◽  
Test Model ◽  
Cfd Simulations ◽  
Fire Engineering ◽  
Diffusion Characteristics ◽  
Fire Loads

The aim of this paper is to examine the effect of wind on the thermal diffusion characteristics of floating production storage and offloading (FSPO) topside models subject to fire. It is motivated by the need to identify the fire loads on FPSO topsides, taking into account the effects of wind speed and direction. The results of an experimental and numerical study undertaken for these purposes are reported here. This paper is part of Phase II of the joint industry project on explosion and fire engineering of FPSOs (EFEF JIP) [1]. An experiment was performed on a 1/14-scale FPSO topside model using a wind tunnel test facility. The locations of the heat source of the fire were varied, as were the speed and direction of the wind, and the temperature distribution was measured. Computational fluid dynamics (CFD) simulations using the ANSYS CFX program were performed on the test model, with the results obtained compared with the experimental results. It is concluded that wind has a significant effect on the thermal diffusion characteristics of the test model and that the CFD simulations are in good agreement with the experimental results. The insights developed in this study will be very useful for the fire engineering of FPSO topsides.

A numerical study of the interaction between unsteay free-stream disturbances and localized variations in surface geometry

1989 ◽  
Vol 209 ◽  
pp. 285-308 ◽  
Author(s):  
R. J. Bodonyi ◽  
W. J. C. Welch ◽  
P. W. Duck ◽  
M. Tadjfar
Keyword(s):  
Numerical Solutions ◽  
Free Stream ◽  
Stokes Equations ◽  
Numerical Study ◽  
Navier Stokes ◽  
Surface Geometry ◽  
Navier Stokes Equations ◽  
S Waves ◽  
Tollmien Schlichting

A numerical study of the generation of Tollmien-Schlichting (T–S) waves due to the interaction between a small free-stream disturbance and a small localized variation of the surface geometry has been carried out using both finite–difference and spectral methods. The nonlinear steady flow is of the viscous–inviscid interactive type while the unsteady disturbed flow is assumed to be governed by the Navier–Stokes equations linearized about this flow. Numerical solutions illustrate the growth or decay of the T–S waves generated by the interaction between the free-stream disturbance and the surface distortion, depending on the value of the scaled Strouhal number. An important result of this receptivity problem is the numerical determination of the amplitude of the T–S waves.

Investigation on the Rheological Behavior of Polyamide6/Montmorillonite Nanocomposites by Reactive Extrusion

2011 ◽  
Vol 233-235 ◽  
pp. 1998-2001 ◽  
Author(s):  
Ming Zhao ◽  
Xiao Zhong Lu ◽  
Kai Gu ◽  
Xiao Min Sun ◽  
Chang Qing Ji
Keyword(s):  
Activation Energy ◽  
Shear Stress ◽  
Shear Rate ◽  
Rheological Behavior ◽  
Reactive Extrusion ◽  
Shear Thinning ◽  
Experimental Results ◽  
Montmorillonite Nanocomposites

The rheological behavior of PA6/montmorillonite(MMT) by reactive extrusion was investigated using cone-and-plate rheometer. The experimental results indicated that PA6/MMT exhibited shear-thinning behavior. The shear stress of both neat PA6 and PA6/MMT increased with the increase in the shear rate. The reduction of the viscous activation energy with the increase of shear stress reflected PA6/MMT can be processed over a wider temperature.

A Numerical and Experimental Investigation of Turbulent Heat Transport Downstream From an Abrupt Pipe Expansion

1983 ◽  
Vol 105 (4) ◽  
pp. 862-869 ◽  
Author(s):  
R. S. Amano ◽  
M. K. Jensen ◽  
P. Goel
Keyword(s):  
Heat Transfer ◽  
Numerical Solutions ◽  
Numerical Study ◽  
Separated Flow ◽  
Flow Region ◽  
Reynolds Numbers ◽  
Turbulent Heat ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Pipe Expansion

An experimental and numerical study is reported on heat transfer in the separated flow region created by an abrupt circular pipe expansion. Heat transfer coefficients were measured along the pipe wall downstream from an expansion for three different expansion ratios of d/D = 0.195, 0.391, and 0.586 for Reynolds numbers ranging from 104 to 1.5 × 105. The results are compared with the numerical solutions obtained with the k ∼ ε turbulence model. In this computation a new finite difference scheme is developed which shows several advantages over the ordinary hybrid scheme. The study also covers the derivation of a new wall function model. Generally good agreement between the measured and the computed results is shown.

Novel fractional hybrid impedance control of series elastic muscle-tendon actuator

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Mohammad Javad Fotuhi ◽  
Zafer Bingul
Keyword(s):  
Contact Stress ◽  
Impedance Control ◽  
Robustness Analysis ◽  
Simulation Models ◽  
Experimental Results ◽  
Uncertain Environments ◽  
Content Type ◽  
Force Tracking ◽  
Comparative Results ◽  
Series Elastic

Purpose This paper aims to develope a novel fractional hybrid impedance control (FHIC) approach for high-sensitive contact stress force tracking control of the series elastic muscle-tendon actuator (SEM-TA) in uncertain environments. Design/methodology/approach In three different cases, the fractional parameters of the FHIC were optimized with the particle swarm optimization algorithm. Its adaptability to the pressure of the sole of the foot on real environments such as grass (soft), carpet (medium) and solid floors (hard) is far superior to traditional impedance control. The main aim of this paper is to derive the dynamic simulation models of the SEM-TA, to develop a control architecture allowing for high-sensitive contact stress force control in three cases and to verify the simulation models and the proposed controller with experimental results. The performance of the optimized controllers was evaluated according to these parameters, namely, maximum overshoot, steady-state error, settling time and root mean squared errors of the positions. Moreover, the frequency robustness analysis of the controllers was made in three cases. Findings Different simulations and experimental results were conducted to verify the control performance of the controllers. According to the comparative results of the performance, the responses of the proposed controller in simulation and experimental works are very similar. Originality/value Origin approach and origin experiment.

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