Model Construction and Finite Element Simulate Based on Experiment Study of Magneto Rheological Finished Machine

2014 ◽  
Vol 620 ◽  
pp. 288-296
Author(s):  
Hang Song Yang ◽  
Peng Li ◽  
Li Zhi Gu ◽  
Hui Juan Guo
Keyword(s):  
Reynolds Number ◽  
Finite Element ◽  
Shear Stress ◽  
Magnetic Fluid ◽  
Critical Reynolds Number ◽  
Fluid Velocity ◽  
Mathematics Model ◽  
Magnetic Liquid ◽  
Fluid State ◽  
Magneto Rheological

In this paper, turn the medium of magneto rheological liquid into continuation, and using of the critical Reynolds number determine method of liquid move state and compound with non-Newton fluid, get the conclusion of finished machine abrasive magnetic liquid fluid as laminar fluid, for having no mathematics’ model practical or be fit with the experiment, especially the distribution of shear and velocity stress, In this paper, using of the critical Reynolds number to determine the liquid state of magnetic fluid state, and in determined the fluid state, using non-Newton fluid dynamics and tensor analysis theory and also compound with the double dynamic viscosity model, analysis the abrasive magnetic fluid quality of kinematics shear stress, according to the quality, contracture the dynamic model of abrasive magnetic liquid finished machine, during the interfere, using the double viscosity fluid model, we may get the conclusion, liquid magnetic abrasive, when the shear stress more or less the bend stress, and mark with plasticity viscosity ηp0, ηpγ which round the work piece center, the velocity distribution as laminar, and also, analysis the flow field mathematics’ model by the finite element, and also going on the numerical simulate for the magnetic fluid velocity field of finished machine.

Drag Coefficient and Settling Velocity of Particles in Non-Newtonian Suspensions

1987 ◽  
Vol 109 (3) ◽  
pp. 319-323 ◽  
Author(s):  
M. Y. Dedegil
Keyword(s):  
Reynolds Number ◽  
Shear Stress ◽  
Drag Coefficient ◽  
Yield Stress ◽  
Particle Velocity ◽  
Settling Velocity ◽  
Fluid Velocity ◽  
Newtonian Fluids ◽  
Drag Forces ◽  
Physical Composition

Drag forces on bodies in non-Newtonian fluids which are to be described by using the Reynolds number should only contain forces which are associated with the fluid velocity or particle velocity. Forces due to the yield stress τ0 must be considered separately. According to its physical composition, the Reynolds number must be calculated by means of the fully representative shear stress including the yield stress τ0. Then the drag coefficient cD as a function of the Reynolds number can be traced back to that of Newtonian fluids.

The Model and Simulation of Magnetorheological Grease Characteristics

2012 ◽  
Vol 246-247 ◽  
pp. 1214-1219 ◽  
Author(s):  
Li Song ◽  
Guo Tian He ◽  
Zhi Zeng ◽  
Yan Ma ◽  
Ming Li ◽  
...  
Keyword(s):  
Complex System ◽  
Shear Stress ◽  
Experimental Curve ◽  
Mathematics Model ◽  
Theoretic Model ◽  
Zero Field ◽  
Model And Simulation ◽  
Stress Curve ◽  
Magnetic Strength ◽  
Magneto Rheological

Magneto-rheological grease attracts the attention as a new kind of intelligent material. Under the external magnetic force, it is difficult to use traditional mathematics model to solve and analysis internal structure because of its complexity and polytropy. The modeling and simulation for complex system using computer becomes a good way to investigate complex system. Based on the electromagnetic theory and computer simulation, this paper constructed the model of shear stress to describe the characteristic of magneto-rheological grease that is to use body centered cubic pillars model to analysis the mechanism and characteristics of magneto-rheological grease. Using matlab simulink toolkit to compose the simulation program, simulate and analysis using theoretic model, and plot the shear stress curve of magneto-rheological grease with magnetic strength and particle size, and the shearing force under zero field. The simulation and experimental results indicate that the simulated shear stress curve is coincidence with experimental curve when the density of ferromagnetic particle is low, and it is lower than experimental curve when the density is high (the variation tendency is close), which verified the accuracy of theoretical model. It needs to improve the model by considering the still friction between ferromagnetic particles.

Stability of a viscous liquid flowing down a flexible boundary

1968 ◽  
Vol 46 (18) ◽  
pp. 2059-2063
Author(s):  
A. S. Gupta
Keyword(s):  
Reynolds Number ◽  
Shear Stress ◽  
Phase Shift ◽  
Viscous Liquid ◽  
Critical Reynolds Number ◽  
Elastic Parameter ◽  
Viscous Damping ◽  
Wave Disturbances ◽  
Long Wave ◽  
The Stability

The stability characteristics of a viscous liquid flowing down a flexible boundary are investigated for long-wave disturbances. In the case of a normally compliant boundary which resembles a thin stretched membrane resting on an elastic foundation with viscous damping, it is found that the critical Reynolds number Rc increases with the elastic parameter. For a boundary showing purely tangential compliance, Rc is found to depend on the phase shift between the oscillation of the shear stress and tangential deformation.

Finite Element Analysis of Tire/Rim Interface Forces Under Braking and Cornering Loads

1992 ◽  
Vol 20 (2) ◽  
pp. 83-105 ◽  
Author(s):  
J. P. Jeusette ◽  
M. Theves
Keyword(s):  
Finite Element ◽  
Shear Stress ◽  
Contact Pressure ◽  
Element Model ◽  
Shear Stresses ◽  
Detailed Knowledge ◽  
Stress Distributions ◽  
Element Analysis ◽  
Plane Shear ◽  
Normal Contact

Abstract During vehicle braking and cornering, the tire's footprint region may see high normal contact pressures and in-plane shear stresses. The corresponding resultant forces and moments are transferred to the wheel. The optimal design of the tire bead area and the wheel requires a detailed knowledge of the contact pressure and shear stress distributions at the tire/rim interface. In this study, the forces and moments obtained from the simulation of a vehicle in stationary braking/cornering conditions are applied to a quasi-static braking/cornering tire finite element model. Detailed contact pressure and shear stress distributions at the tire/rim interface are computed for heavy braking and cornering maneuvers.

scholarly journals A Novel Particle-Based Approach for Modeling a Wet Vertical Stirred Media Mill

Minerals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 55
Author(s):  
Simon Larsson ◽  
Juan Manuel Rodríguez Prieto ◽  
Hannu Heiskari ◽  
Pär Jonsén
Keyword(s):  
Finite Element Method ◽  
Reynolds Number ◽  
Finite Element ◽  
Grinding Fluid ◽  
Novel Approach ◽  
Grinding Media ◽  
Interparticle Contacts ◽  
Mineral Slurry ◽  
Stirred Media Mill ◽  
Element Method

Modeling of wet stirred media mill processes is challenging since it requires the simultaneous modeling of the complex multiphysics in the interactions between grinding media, the moving internal agitator elements, and the grinding fluid. In the present study, a multiphysics model of an HIG5 pilot vertical stirred media mill with a nominal power of 7.5 kW is developed. The model is based on a particle-based coupled solver approach, where the grinding fluid is modeled with the particle finite element method (PFEM), the grinding media are modeled with the discrete element method (DEM), and the mill structure is modeled with the finite element method (FEM). The interactions between the different constituents are treated by loose (or weak) two-way couplings between the PFEM, DEM, and FEM models. Both water and a mineral slurry are used as grinding fluids, and they are modeled as Newtonian and non-Newtonian fluids, respectively. In the present work, a novel approach for transferring forces between grinding fluid and grinding media based on the Reynolds number is implemented. This force transfer is realized by specifying the drag coefficient as a function of the Reynolds number. The stirred media mill model is used to predict the mill power consumption, dynamics of both grinding fluid and grinding media, interparticle contacts of the grinding media, and the wear development on the mill structure. The numerical results obtained within the present study show good agreement with experimental measurements.

scholarly journals The Effect of Wall Shear Stress on Two Phase Fluctuating Flow of Dusty Fluids by Using Light Hill Technique

Water ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1587
Author(s):  
Dolat Khan ◽  
Ata ur Rahman ◽  
Gohar Ali ◽  
Poom Kumam ◽  
Attapol Kaewkhao ◽  
...  
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Base Fluid ◽  
Perturbation Technique ◽  
Fluid Velocity ◽  
Dust Particles ◽  
Stress Effect ◽  
Parallel Plates ◽  
Dusty Fluid ◽  
Wall Shear

Due to the importance of wall shear stress effect and dust fluid in daily life fluid problems. This paper aims to discover the influence of wall shear stress on dust fluids of fluctuating flow. The flow is considered between two parallel plates that are non-conducting. Due to the transformation of heat, the fluid flow is generated. We consider every dust particle having spherical uniformly disperse in the base fluid. The perturb solution is obtained by applying the Poincare-Lighthill perturbation technique (PLPT). The fluid velocity and shear stress are discussed for the different parameters like Grashof number, magnetic parameter, radiation parameter, and dusty fluid parameter. Graphical results for fluid and dust particles are plotted through Mathcad-15. The behavior of base fluid and dusty fluid is matching for different embedded parameters.

scholarly journals Finite Element Analysis of Composite Repair for Damaged Steel Pipeline

Coatings ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 301
Author(s):  
Jiaqi Chen ◽  
Hao Wang ◽  
Milad Salemi ◽  
Perumalsamy N. Balaguru
Keyword(s):  
Finite Element ◽  
Shear Stress ◽  
Hoop Stress ◽  
Pipe Wall ◽  
Von Mises Stress ◽  
Repair System ◽  
Composite Repair ◽  
Steel Pipeline ◽  
Von Mises ◽  
Infill Material

Carbon fiber reinforced polymer (CFRP) matrix composite overwrap repair systems have been introduced and accepted as an alternative repair system for steel pipeline. This paper aimed to evaluate the mechanical behavior of damaged steel pipeline with CFRP repair using finite element (FE) analysis. Two different repair strategies, namely wrap repair and patch repair, were considered. The mechanical responses of pipeline with the composite repair system under the maximum allowable operating pressure (MAOP) was analyzed using the validated FE models. The design parameters of the CFRP repair system were analyzed, including patch/wrap size and thickness, defect size, interface bonding, and the material properties of the infill material. The results show that both the stress in the pipe wall and CFRP could be reduced by using a thicker CFRP. With the increase in patch size in the hoop direction, the maximum von Mises stress in the pipe wall generally decreased as the maximum hoop stress in the CFRP increased. The reinforcement of the CFRP repair system could be enhanced by using infill material with a higher elastic modulus. The CFRP patch tended to cause higher interface shear stress than CFRP wrap, but the shear stress could be reduced by using a thicker CFRP. Compared with the fully bonded condition, the frictional interface causes a decrease in hoop stress in the CFRP but an increase in von Mises stress in the steel. The study results indicate the feasibility of composite repair for damaged steel pipeline.

Stability of thermocapillary flows in non-cylindrical liquid bridges

2002 ◽  
Vol 458 ◽  
pp. 35-73 ◽  
Author(s):  
CH. NIENHÜSER ◽  
H. C. KUHLMANN
Keyword(s):  
Reynolds Number ◽  
Prandtl Number ◽  
Critical Reynolds Number ◽  
Volume Fraction ◽  
Thermocapillary Flow ◽  
Surface Shape ◽  
Liquid Bridges ◽  
Gravity Level ◽  
Neutral Curves ◽  
Prandtl Numbers

The thermocapillary flow in liquid bridges is investigated numerically. In the limit of large mean surface tension the free-surface shape is independent of the flow and temperature fields and depends only on the volume of liquid and the hydrostatic pressure difference. When gravity acts parallel to the axis of the liquid bridge the shape is axisymmetric. A differential heating of the bounding circular disks then causes a steady two-dimensional thermocapillary flow which is calculated by a finite-difference method on body-fitted coordinates. The linear-stability problem for the basic flow is solved using azimuthal normal modes computed with the same discretization method. The dependence of the critical Reynolds number on the volume fraction, gravity level, Prandtl number, and aspect ratio is explained by analysing the energy budgets of the neutral modes. For small Prandtl numbers (Pr = 0.02) the critical Reynolds number exhibits a smooth minimum near volume fractions which approximately correspond to the volume of a cylindrical bridge. When the Prandtl number is large (Pr = 4) the intersection of two neutral curves results in a sharp peak of the critical Reynolds number. Since the instabilities for low and high Prandtl numbers are markedly different, the influence of gravity leads to a distinctly different behaviour. While the hydrostatic shape of the bridge is the most important effect of gravity on the critical point for low-Prandtl-number flows, buoyancy is the dominating factor for the stability of the flow in a gravity field when the Prandtl number is high.

Dynamic Behavior of Cellular Materials under Combined Shear-Compression

2016 ◽  
Vol 835 ◽  
pp. 649-653
Author(s):  
Yuan Yuan Ding ◽  
Shi Long Wang ◽  
Zhi Jun Zheng ◽  
Li Ming Yang ◽  
Ji Lin Yu
Keyword(s):  
Finite Element ◽  
Shear Stress ◽  
Finite Element Model ◽  
Nonlinear Regression ◽  
Element Model ◽  
Cellular Materials ◽  
Regression Method ◽  
Plateau Stress ◽  
Nonlinear Regression Method ◽  
Biaxial Behavior

A 3D cell-based finite element model is employed to investigate the dynamic biaxial behavior of cellular materials under combined shear-compression. The biaxial behavior is characterized by the normal stress and shear stress, which could be determined directly from the finite element results. A crush plateau stress is introduced to illustrate the critical crush stress, and the result shows that the normal plateau stress declines with the increase of the shear plateau stress, which climbs with the increase of loading angle. An elliptical criterion of normal plateau stress vs. shear plateau stress is obtained by the nonlinear regression method.

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