Yield stress of structured fluids measured by squeeze flow

2000 ◽  
Vol 39 (4) ◽  
pp. 399-408 ◽  
Author(s):  
Gerald H. Meeten
Keyword(s):  
Yield Stress ◽  
Squeeze Flow ◽  
Structured Fluids

The rising motion of spheres in structured fluids with yield stress

2017 ◽  
Vol 29 (9) ◽  
pp. 093101 ◽  
Author(s):  
S. Mirzaagha ◽  
R. Pasquino ◽  
E. Iuliano ◽  
G. D’Avino ◽  
F. Zonfrilli ◽  
...  
Keyword(s):  
Yield Stress ◽  
Structured Fluids

scholarly journals Application Of CFD To Modeling Of Squeeze Mode Magnetorheological Dampers

2015 ◽  
Vol 9 (3) ◽  
pp. 129-134 ◽  
Author(s):  
Janusz Gołdasz ◽  
Bogdan Sapiński
Keyword(s):  
Magnetic Field ◽  
Yield Stress ◽  
Flow Model ◽  
Squeeze Flow ◽  
Channel Height ◽  
Ansys Fluent ◽  
Mr Fluid ◽  
Planar Surfaces ◽  
Force Profile ◽  
Magnetic Field Magnitude

Abstract The so-called squeeze flow involves a magnetorheological (MR) fluid sandwiched between two planar surfaces setting up a flow channel. The height of the channel varies according to a prescribed displacement or force profile. When exposed to a magnetic field of sufficient strength MR fluids develop a yield stress. In squeeze-mode devices the yield stress varies with both the magnetic field magnitude and the channel height. In this paper an unsteady flow model of an MR fluid in squeeze mode is proposed. The model is developed in Ansys Fluent R16. The MR material flow model is based on the apparent viscosity approach. In order to investigate the material's behaviour the authors prepared a model of an idealized squeeze-mode damper in which the fluid flow is enforced by varying the height of the channel. Using mesh animation, the model plate is excited, and as the mesh moves, the fluid is squeezed out of the gap. In the simulations the model is subjected to a range of displacement inputs of frequencies from 10 to 20 Hz, and local yield stress levels up to 30 kPa. The results are presented in the form of time histories of the normal force on the squeezing plate and loops of force vs. displacement (velocity).

Experimental Procedures of Characterizing the Viscoelastic Properties of Certain Materials

1999 ◽  
Author(s):  
V. Dakshina Murty
Keyword(s):  
Yield Stress ◽  
Newtonian Fluid ◽  
Material Properties ◽  
Viscoelastic Properties ◽  
Extrusion Process ◽  
Squeeze Flow ◽  
Generalized Newtonian Fluid ◽  
Flow Process ◽  
Bingham Plastic ◽  
Effects Of Temperature

Abstract Experimental procedures for characterizing the material properties of viscoelastic materials are proposed. The procedures described are based on extrusion process and squeeze flow process. The fundamental features within each of these procedures are discussed in detail. If the material is assumed to be either a generalized Newtonian fluid or Bingham plastic, the relevant parameters are the viscosity and yield stress. The results of the experiments on these two properties are shown along with the effects of temperature on the yield stress are discussed.

scholarly journals Influence of Squeezing Rate on Yield Stress and Viscosity of Fresh Mortar

2020 ◽  
Vol 10 (4) ◽  
pp. 5921-5924 ◽  
Author(s):  
V. T. Phan ◽  
D. D. Nguyen
Keyword(s):  
Phase Separation ◽  
Yield Stress ◽  
Atmospheric Pressure ◽  
Room Temperature ◽  
Solid Phase ◽  
Elongational Viscosity ◽  
Squeeze Flow ◽  
Fresh State ◽  
Order Of Magnitude ◽  
Flow Techniques

In the present work, squeeze flow techniques were used to investigate the influence of squeezing rates on the yield stress of mortars in fresh state. The tested samples were prepared under similar conditions of room temperature and atmospheric pressure. The fresh mortars were tested at three squeezing rates (20 and 200mm/s) 15 minutes after mixing. The results show that the material’s yield stress increases with the increasing of the squeeze velocity. This increase is evident at low tensile speeds and is not obvious at high tack velocity. Elongational viscosity values increased as a result of the gap reduction for all the tested samples. However, when the squeeze speed was high, the strain rate increased because of the high displacement rates, a significant reduction in the mortar’s elongational viscosity was observed compared with those obtained when the squeeze speed was low. Despite that this behavior is associated with fluid-solid phase separation, which occurs for low displacement rates, these viscosity values actually represent the behavior of the material in practical situations when submitted to different velocities. The increase in the displacement rate of one order of magnitude caused a reduction in the viscosity of one order of magnitude.

scholarly journals Influence of Tack Speed on The Rheological Properties of Mortar in Fresh State

2020 ◽  
Vol 10 (5) ◽  
pp. 6249-6252
Author(s):  
V. T. Phan
Keyword(s):  
Rheological Properties ◽  
Yield Stress ◽  
Atmospheric Pressure ◽  
High Speed ◽  
Room Temperature ◽  
Elongational Viscosity ◽  
Extensional Viscosity ◽  
Squeeze Flow ◽  
Fresh State ◽  
Flow Techniques

In the present work, the squeeze flow techniques were used to investigate the influence of tack speed to the rheological properties of mortar in fresh sate, including yield stress and extensional viscosity.Tested samples were prepared under similar conditions of room temperature and atmospheric pressure. Compositions of mortars were tested at two different squeezing rates (20 and 200 mm/s) 15 min after mixing. Results indicate that mortar’s yield stress increases with the increasing of the pulling speed. This increase is evident at low tensile speeds. At high speed of tack, this increase is not obvious, especially in case of high squeeze speed of 200 mm/s. It can be concluded that the optima speed for removing the mortar and the upper surface is lower than 20 mm/s. The extensional viscosity of fresh mortars significantly decrease as the tack speed increases. Elongational viscosity values decreased as a result of gap increasing. The increase of the gap during tack experiment stimulates different units (grains getting far apart to each other) causing the observed decrease of the mortars' elongational viscosity

Dynamic characteristics of magnetorheological fluid squeeze flow considering wall slip and inertia

2019 ◽  
Vol 31 (2) ◽  
pp. 229-242 ◽  
Author(s):  
Xinjie Zhang ◽  
Ruochen Wu ◽  
Konghui Guo ◽  
Piyong Zu ◽  
Mehdi Ahmadian
Keyword(s):  
Yield Stress ◽  
Excitation Frequency ◽  
Dynamic Environment ◽  
Dynamic Test ◽  
Inertial Force ◽  
Control Valve ◽  
Wall Slip ◽  
Magnetorheological Fluid ◽  
Squeeze Flow ◽  
Vertical Force

Magnetorheological fluid has been investigated intensively nowadays, and magnetorheological fluid shows large force capabilities in squeeze mode with wide application potential such as control valve, engine mounts, and impact dampers. In these applications, magnetorheological fluid is flowing in a dynamic environment due to the transient nature of inputs and system characteristics. Hence, this article undertakes a comprehensive study of magnetorheological fluid squeeze flow dynamics behaviors with wall slip, yield, and inertia. First, the dynamic model with the bi-viscous constitutive of magnetorheological fluid squeeze flow including wall slip and inertial force is presented. Then, the mathematical model is validated, matching magnetorheological fluid squeeze dynamic test results very well. Finally, the dynamics behavior and mechanism of magnetorheological fluid squeeze flow with inertia, yield, and wall slip are explored. Results show that (1) increasing yield stress and decreasing initial gap will increase the magnetorheological fluid vertical force greatly; (2) the wall slip affects the yield surface of magnetorheological fluids in the squeeze zone and affects the squeeze force; (3) the inertial force is increasing tremendously as the increased excitation frequency and yield stress and should be included with high-frequency excitation or yield stress.

The Squeeze Flow of Yield Stress Fluids

2008 ◽  
Author(s):  
Brooks D. Rabideau ◽  
Christophe Lanos ◽  
Philippe Coussot ◽  
Albert Co ◽  
Gary L. Leal ◽  
...  
Keyword(s):  
Yield Stress ◽  
Squeeze Flow ◽  
Yield Stress Fluids

An investigation of squeeze flow as a viable technique for determining the yield stress

2009 ◽  
Vol 48 (5) ◽  
pp. 517-526 ◽  
Author(s):  
Brooks D. Rabideau ◽  
Christophe Lanos ◽  
Philippe Coussot
Keyword(s):  
Yield Stress ◽  
Squeeze Flow
Sign in / Sign up

Export Citation Format

Share Document