A SINGLE-CHAIN MODEL FOR QUASI-STATIC SHEAR STRESS-STRAIN PROPERTIES OF MAGNETORHEOLOGICAL FLUIDS

2002 ◽  
Vol 16 (17n18) ◽  
pp. 2739-2744 ◽  
Author(s):  
ZEHUI JIANG ◽  
KUNQUAN LU
Keyword(s):  
Magnetic Field ◽  
Shear Stress ◽  
Interaction Energy ◽  
Uniform Magnetic Field ◽  
Magnetorheological Fluids ◽  
Single Chain ◽  
Stress Strain ◽  
Magnetic Spheres ◽  
A Chain ◽  
Static Shear

The quasi-static shear stress-strain property of magnetorheological fluids is analyzed, based on the calculation of the interaction energy of chain of equi-spaced magnetic spheres with the applied uniform magnetic field. First, the dipole moment of a chain of equi-spaced magnetic spheres imposed to a uniform magnetic field is determined, and simple expressions are given. Then, the interaction energy of a chain with the forcing field is determined, and the restoring force is calculated when the chain is slanted and elongated. In our analysis, only the contributions from the mutual interaction of the particles in chains are considered. Comparison with experimental results is made, and good agreement is obtained.

Squeeze behavior of magnetorheological fluids under constant volume and uniform magnetic field

2013 ◽  
Vol 22 (4) ◽  
pp. 045020 ◽  
Author(s):  
Chaoyang Guo ◽  
Xinglong Gong ◽  
Shouhu Xuan ◽  
Qifan Yan ◽  
Xiaohui Ruan
Keyword(s):  
Magnetic Field ◽  
Uniform Magnetic Field ◽  
Magnetorheological Fluids ◽  
Constant Volume

A mathematical analysis of MHD blood flow of Eyring–Powell fluid through a constricted artery

2016 ◽  
Vol 09 (02) ◽  
pp. 1650027 ◽  
Author(s):  
Najma Saleem ◽  
Sufian Munawar
Keyword(s):  
Magnetic Field ◽  
Mathematical Model ◽  
Blood Flow ◽  
Shear Stress ◽  
Pressure Drop ◽  
Mathematical Analysis ◽  
Uniform Magnetic Field ◽  
Symmetric Form ◽  
Regular Perturbation ◽  
Irregular Shapes

The present study deals with the flow of blood through a stenotic artery in the presence of a uniform magnetic field. Different flow situations are taken into account by considering the regular and irregular shapes of stenosis lying inside the walls of artery. Blood inside the artery is assumed to be Eyring–Powell fluid. A mathematical model is developed and simplified under the physical assumptions of stenosis. The regular perturbation method is adopted to find the solutions for axial velocity and pressure gradient. The variations in pressure drop across the stenosis length, the impedance and the shear stress at the walls of stenotic artery are discussed in detail through graphs. It is observed that the Eyring–Powell fluid is helpful in reducing the resistance to the flow in stenotic artery. Moreover, symmetric form of stenosis is more hazardous as compared to asymmetric stenosis.

Study on Microstructure and Mechanical Behavior of Magnetorheological Fluids with Mixed Particles

2011 ◽  
Vol 216 ◽  
pp. 465-468 ◽  
Author(s):  
Hai Tao Li ◽  
Xiang He Peng
Keyword(s):  
Magnetic Field ◽  
Mechanical Properties ◽  
Particle Size ◽  
Shear Stress ◽  
External Magnetic Field ◽  
Mechanical Behavior ◽  
Magnetorheological Fluids ◽  
Size Ratio ◽  
Mr Fluids ◽  
Particle Size Ratio

The microstructure and mechanical properties of magnetorheological (MR) fluids with mixed particles of different size are investigated. The interaction between particles of different radius is obtained and the model for motion of particles is proposed. Under an external magnetic field, the microstructure and yield shear stress of MR fluids with mixed particles of different sizes are simulated. It shows that particle size ratio in bidisperse suspensions can influence the performance of MR fluids.

Measurement of single three-dimensional moduli to evaluate the effect of a uniform magnetic field on magnetorheological fluids

2020 ◽  
Vol 59 (3) ◽  
pp. 157-163
Author(s):  
Carlos Gracia-Fernández ◽  
Silvia Gómez-Barreiro ◽  
Ana Álvarez-García ◽  
Ana María Díaz-Díaz ◽  
Jorge López-Beceiro ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Uniform Magnetic Field ◽  
Three Dimensional ◽  
Magnetorheological Fluids

Enhance the Yield Shear Stress of Magnetorheological Fluids

2001 ◽  
Vol 15 (06n07) ◽  
pp. 549-556 ◽  
Author(s):  
X. TANG ◽  
X. ZHANG ◽  
R. TAO
Keyword(s):  
Magnetic Field ◽  
Shear Stress ◽  
Yield Stress ◽  
Chain Structure ◽  
Single Chain ◽  
Compression Pressure ◽  
Sem Images ◽  
Mr Fluid ◽  
Mr Fluids ◽  
Yield Shear Stress

To enhance the yield shear stress of magnetorheological (MR) fluids is an important task. Since thick columns have a yield stress much higher than a single-chain structure, we enhance the yield stress of an MR fluids by changing the microstructure of MR fluids. Immediately after a magnetic field is applied, we compress the MR fluid along the field direction. SEM images show that the particle chains are pushed together to form thick columns. The shear force measured after the compression indicates that the yield stress can reach as high as 800 kPa under a moderate magnetic field, while the same MR fluid has a yield stress of 80 kPa without compression. This enhanced yield stress increases with the magnetic field and compression pressure and has an upper limit well above 800 kPa. The method is also applicable to electrorheological fluids.

scholarly journals Analysis and Experimental Study on Rheological Performances of Magnetorheological Fluids

Mechanika ◽  
2020 ◽  
Vol 26 (1) ◽  
pp. 31-34
Author(s):  
Chao LIU ◽  
Jianxin XIE ◽  
Dongling CAI
Keyword(s):  
Magnetic Field ◽  
Experimental Study ◽  
Shear Stress ◽  
Shear Rate ◽  
Volume Fraction ◽  
Magnetorheological Fluids ◽  
Bingham Model ◽  
Shear Thinning Fluids ◽  
Powder Rheometer ◽  
Constant Shear Rate

Silicone-based Magnetorheological Fluids (MRFs) were prepared with 10% volume fraction of carbonyl iron powder. Rheometer Physica MCR 301 was used to test the rheological performances of MRFs.The experimental results show Bingham model and Casson model could well describe rheological behaviors of MRFs. Shear stress of MRFs increases but apparent viscosity is significantly decreased and tends to be stable with the increase of shear rate in the presence of magnetic field. The results also show that MRFs are shear thinning fluids. The dependence of shear stress on magnetic field was tested under the condition of constant shear rate and increasing magnetic field, shear stress of MRFs increases remarkably.

Research on MRF Shear Stress Measurement Method under Non-Uniform Magnetic

2014 ◽  
Vol 620 ◽  
pp. 347-350
Author(s):  
Shao Qing Ren ◽  
Chun Fu Gao ◽  
Peng Huang ◽  
Xin Sheng He ◽  
Hong Yun Wang ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Field Theory ◽  
Shear Stress ◽  
Uniform Magnetic Field ◽  
Fluid Shear Stress ◽  
Large Deviation ◽  
Stress Measurement ◽  
Uniform Field ◽  
Application Process ◽  
Magneto Rheological

Magnetorheological fluid as an important branch of the emerging intelligent material, its excellent characteristics make it widely used in electrical system and mechanical system. Common MRF system environment is limited to a uniform magnetic field, the practical application process to the vast of magneto rheological characteristics devices has shown the phenomenon, which does not match the uniform magnetic field theory, the reason is that the actual work environment is the non-uniform magnetic [1-2]. To study the characteristics of MRF shear stress in a non-uniform magnetic field, this paper established a non-uniform field magneto-rheological fluid shear stress measurement device. Comparing the experimental shear stress curves with the uniform magnetic field measured shear stress curves, we found that the non-uniform magnetic field strength of the environmental equivalent shear stress values ​​compared with the uniform magnetic field data have large deviation, this indicates that the existing uniform magnetic field theory is not well to explain non-uniform magnetic field shear properties of MRF, we need to build the introduction of non-uniform magnetic field theory.

scholarly journals Dynamics of a Pair of Paramagnetic Janus Particles under a Uniform Magnetic Field and Simple Shear Flow

2021 ◽  
Vol 7 (1) ◽  
pp. 16
Author(s):  
Christopher Sobecki ◽  
Jie Zhang ◽  
Cheng Wang
Keyword(s):  
Magnetic Field ◽  
Magnetic Material ◽  
Shear Flow ◽  
Simple Shear ◽  
Uniform Magnetic Field ◽  
Particle Orientation ◽  
Viscous Force ◽  
Simple Shear Flow ◽  
A Chain ◽  
The Right

We numerically investigate the dynamics of a pair of circular Janus microparticles immersed in a Newtonian fluid under a simple shear flow and a uniform magnetic field by direct numerical simulation. Using the COMSOL software, we applied the finite element method, based on an arbitrary Lagrangian-Eulerian approach, and analyzed the dynamics of two anisotropic particles (i.e., one-half is paramagnetic, and the other is non-magnetic) due to the center-to-center distance, magnetic field strength, initial particle orientation, and configuration. This article considers two configurations: the LR-configuration (magnetic material is on the left side of the first particle and on the right side of the second particle) and the RL-configuration (magnetic material is on the right side of the first particle and on the left side of the second particle). For both configurations, a critical orientation determines if the particles either attract (below the critical) or repel (above the critical) under a uniform magnetic field. How well the particles form a chain depends on the comparison between the viscous and magnetic forces. For long particle distances, the viscous force separates the particles, and the magnetic force causes them to repel as the particle orientation increases above the configuration’s critical value. As the initial distance decreases, a chain formation is possible at a steady orientation, but is more feasible for the RL-configuration than the LR-configuration under the same circumstances.

Sign in / Sign up

Export Citation Format

Share Document