scholarly journals Turbulence Intensity Characteristics of a Magnetoliquid Seal Interface in a Liquid Environment

Coatings ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1333
Author(s):  
Wangxu Li ◽  
Zhenggui Li ◽  
Ziyue Wang ◽  
Feng Wu ◽  
Lianchen Xu ◽  
...  
Keyword(s):  
Magnetic Fluid ◽  
Turbulence Intensity ◽  
Interface Layer ◽  
Liquid Interface ◽  
Magnetic Liquid ◽  
Liquid Environment ◽  
Linear Pattern ◽  
Liquid Seal ◽  
Fluent Software ◽  
The Stability

In a liquid environment, the turbulence intensity of the interfacial layer between the magnetic and sealing medium fluids in magnetic liquid seals directly affects the layer stability. Reducing the maximum turbulence intensity of the fluid interface layer effectively improves the stability of the magnetic fluid rotary seal. In this study, we simulated magnetic fluid sealing devices with different structures in liquid environments using the FLUENT software. The simulation results were verified through experimental analyses of the turbulence intensity at the sealing interface. The maximum turbulence intensity of the liquid interface layer increased with increasing shaft speed. At the same speed, the turbulence intensity was maximized at the shaft interface before gradually decreasing in a multistage linear pattern along the radial direction. A magnetic liquid seal with an optimized structure (OS) in the liquid environment was designed based on these results. The maximum turbulence intensity of the liquid interface layer in the OS was independent of the rotation speed and was more than 20% lower than that that in the traditional structure. These results provide a reference for designing magnetic liquid sealing devices.

scholarly journals Effect of turbulence intensity of fluid medium interface layer on magnetic liquid seal in liquid environment

2021 ◽  
Author(s):  
Wangxu Li ◽  
Zhenggui Li ◽  
Jie Cheng ◽  
Lianchen Xu ◽  
Xinrui Li
Keyword(s):  
Turbulence Intensity ◽  
Magnetic Induction ◽  
Interface Layer ◽  
Magnetic Liquid ◽  
Fluid Medium ◽  
Liquid Environment ◽  
Liquid Seal ◽  
The Stability ◽  
Traditional Structures ◽  
Magnetic Induction Intensity

Abstract In a liquid environment, the instability of the interface layer of the rotating fluid medium is one of the main causes for the failure of magnetic liquid seals. The turbulence intensity of the interfacial layer between the magnetic and the sealing medium fluids in magnetic liquid seals directly affects the layer stability. Reducing the maximum turbulence intensity is an effective way to improve the stability of the magnetic fluid rotating seal. In this study, we simulated magnetic fluid sealing devices with different structures in liquid environments using FLUENT software. The simulation results are verified through experimental analyses and the turbulence intensity at the sealing interface is analyzed. We simulated the magnetic circuit using Maxwell software, and compared the difference between the optimized and traditional structures. The results show that the maximum turbulence intensity of the liquid interface layer increases with the increasing shaft speed. At the same speed, the turbulence intensity is maximized at the shaft interface before gradually decreasing in a multistage linear pattern along the radial direction. The turbulence intensity at the interface of the spindle is relatively large, which seriously affects the stability of the interface. Based on these results, the optimized structure (OS) of the magnetic liquid seal in the liquid environment is designed. The maximum turbulence intensity of the liquid interface layer in the OS is more than 20% lower than that in the traditional structure (TS), and it is independent of the rotation speed. The optimized and the traditional structures have the same magnetic induction intensity distribution at the sealing clearance. The maximum magnetic induction intensity of the OS is 6.25% higher than that of the traditional one. These results provide a reference for designing magnetic liquid sealing devices.

RESEARCH OF PROPERTIES OF MAGNETIC LUBRICANTS BASED ON ORGANOSILICON LIQUID

2020 ◽  
pp. 26-32
Author(s):  
V.V. Terentyev ◽  
◽  
А. М. Bausov ◽  
М. V. Toropov ◽  
◽  
...  
Keyword(s):  
Magnetic Field ◽  
Mathematical Model ◽  
Oleic Acid ◽  
Magnetic Fluid ◽  
Magnetic Fluids ◽  
Ferromagnetic Phase ◽  
Magnetic Liquid ◽  
Metal Base ◽  
Adhesion Coefficient ◽  
The Stability

The results of research on lubricants which are magnetic fluids are presented. The positive effect on the characteristics of the lubricant of pondemotor force that occurs when an external magnetic field is applied is noted. The purpose of this work is to study the properties of magnetic lubricants based on polyethylsiloxane liquids and confirm the previously stated theoretical assumptions. The main objectives of the research are to develop the composition of a lubricant based on a polyethylsiloxane magnetic fluid, to determine the characteristics of adhesion of this material to a metal base, to obtain an adequate mathematical model describing the characteristics of adhesion of the lubricant to the surface, and to determine its stability during operation. Experimental installations and methods for determining the characteristics of the coupling of magnetic fluids with the friction surface, as well as the stability of magnetic fluid itself during operation, have been developed. The prospects of introducing oleic acid into the organosilicon base of the magnetic liquid are noted. A decrease in the adhesion coefficient with an increase in the rotational speed of the samples at loads from 160 N to 320 N was revealed by an average of 1.6...2.7 times. It is proved that the magnetic lubricant adheres to the metal base more strongly than Litol-24 by an average of 6 times, which prevents the rolling elements from slipping during the operation of the samples. Different patterns of changes in adhesion to metal surfaces of Litol-24 and magnetic fluids are noted. An increase in the adhesion coefficient of magnetic fluids under the conditions of applying a constant magnetic field at loads on samples from 480 N to 800 N due to the magnetorheological effect by 20...30% is established. A mathematical model is obtained that adequately describes the change in the adhesion coefficient of the obtained magnetic lubricant. The composition of the magnetic liquid is recommended, consisting of a polyethylene siloxane carrier liquid, a surfactant-oleic acid, and a ferromagnetic phase-magnetite with a particle size of 7.5 nm. High stability of the developed magnetic fluids during longterm operation has been experimentally established. The stability coefficient of the magnetic fluid decreased by 2.51 times in 366 hours.

Study on Preparation of Oil-Based Fe3O4 Nano Magnetic Fluid

2010 ◽  
Vol 148-149 ◽  
pp. 808-811
Author(s):  
Bing Chen ◽  
Yu Guang Fan ◽  
San Pin Zhou
Keyword(s):  
Saturation Magnetization ◽  
Magnetic Fluid ◽  
Heating Temperature ◽  
Orthogonal Design ◽  
Nano Particles ◽  
Reaction Conditions ◽  
Mechanical Dispersion ◽  
Naoh Solution ◽  
Vibration Magnetometer ◽  
The Stability

Adopting chemical coprecipitation and mechanical dispersion to prepare oil based magnetic fluid is a good way to increase the stability of magnetic fluid. This paper uses orthogonal design to analyze the influences from different factors, and The size of nano-particles and saturation magnetization were characterized by TEM and WSM vibration magnetometer. The results show that the NaOH solution adding speed of 0.4 ml/s and reaction temperature of 50 ~55 , sodium oleate solution adding speed of 0.3ml/s and heating temperature of 65 , heat-maintaining time of 20min are proper reaction conditions.

scholarly journals Effect of YAl2 Particles on the Corrosion Behavior of Mg–Li Matrix Composite in NaCl Solution

Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 549 ◽  
Author(s):  
Zihan Chen ◽  
Chonggao Bao ◽  
Guoqing Wu ◽  
Yongxin Jian ◽  
Li Zhang
Keyword(s):  
Corrosion Resistance ◽  
Intermetallic Compound ◽  
Corrosion Behavior ◽  
Matrix Composite ◽  
Surface Film ◽  
Interface Layer ◽  
Corrosion Products ◽  
Nacl Solution ◽  
The Stability ◽  
Main Factor

The strength of Mg–Li alloy is greatly improved by the composite strengthening of intermetallic compound YAl2 particles, but the low corrosion resistance of Mg–Li alloy is still the main factor that restricts the application of the alloy and its composites. In this paper, the effect of YAl2 particles on the corrosion behavior of Mg–Li alloy was systematically investigated. The results showed that the corrosion resistance of YAl2p/LA143 composite could be significantly improved, accounting for the formation of a transitional interface layer by adding YAl2 particles. The diffusion of yttrium and aluminum atoms from YAl2 particulates improved the stability of the surface film and enhanced the adhesion between the corrosion products and the substrate, which hindered further expansion of pitting.

Development of a magnetic liquid seal for clean robots

1987 ◽  
Vol 65 (2-3) ◽  
pp. 385-388 ◽  
Author(s):  
M. Mizumoto ◽  
H. Inoue
Keyword(s):  
Magnetic Liquid ◽  
Liquid Seal

scholarly journals Some peculiar features of hydrodynamic instability development

2013 ◽  
Vol 371 (2003) ◽  
pp. 20120288 ◽  
Author(s):  
E. Meshkov
Keyword(s):  
Hydrodynamic Instability ◽  
Liquid Interface ◽  
Necessary Condition ◽  
Density Jump ◽  
Interface Instability ◽  
Heavy Medium ◽  
Instability Development ◽  
Rayleigh Taylor Instability ◽  
Heavy Gas ◽  
The Stability

We discuss the results of experiments that illustrate some features of a turbulent mixing zone (TMZ) structure at a gas–liquid interface (Rayleigh–Taylor instability) and at a gas–gas interface accelerated by shock waves (Richtmyer–Meshkov instability). The important feature is the existence of a heavier substance concentration (density) jump at the interface between the heavy medium and the TMZ. It is found that the existence of this jump is a generic feature of any developed TMZ and is the necessary condition for its continuous development. In the case of a gas–liquid interface, the stable existence of this jump is connected with the stability of the cupola of gas bubbles penetrating into the liquid in a TMZ. The important feature of the development of interface instability accelerated by an unsteady shock is the decaying ability (up to full suppression) of the interface instability in the case when a decaying wave passes through the interface in the direction from light gas to heavy gas.

Stability of Thermoelectromagnetic Convection

2006 ◽  
Author(s):  
Brent C. Houchens
Keyword(s):  
Numerical Solutions ◽  
Liquid Interface ◽  
Analytical And Numerical Solutions ◽  
The Stability ◽  
Solid Liquid Interface ◽  
Solid Liquid ◽  
Initial Results

The role of thermoelectromagnetic convection (TEMC) on the stability of a range of flows is investigated. Here we discuss the general features of TEMC, and describe experiments in which this effect is thought to have significance. The general formulation for TEMC at a solid-liquid interface is presented. Initial results are benchmarked with existing analytical and numerical solutions.

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