Papers by Keyword: Electrorheological Fluid

Abstract: Electrorheological fluids (ERFs) can change their shear stress and shear rate as a function of the electric field intensity thus, such fluids acts as Newtonian fluids, if no electric field is applied and, become non Newtonian fluids if the presence of an electric field. In the last years, a growth interest is manifested for incorporating smart fluids into structures, as clutches or dumpers. The ERFs shear rate and shear stress must be determined at the moment of designing such mechanical structures. The fluids viscosity is studied by aid of commercially available viscosimeters or rheometers, these do not have the possibility to apply an electric field to the studied fluids. The ER fluids must be studied into specific electric field intensity. This paper presents: a low cost experimental rheometer and experimental results obtained form a study of several commercially available ERFs.

Abstract: Electrorheological fluid (ERF) is a new kind of smart materials, which has a great deal of market value and broad application prospects. To meet the needs of the ERFs performance testing, design and produce of the ERF's performance test system are based on the relationship of the apparent viscosity, shear stress and electric field strength. Select the NDJ-8S digital viscometer, high voltage DC power supply, liquid container, and other parts to constitute the ERFs performance test system after considering the relationship of the apparent viscosity, shear stress, shear rate and electric field strength. The system has potentials to control voltage, change velocity, change the distance between the parallel panels, and test the yield stress of the ERF, shear stress, viscosity and other parameters. The study introduces the hardware and software device, the related experiments, and obtains the relationship of the viscosity, rotational speed, voltage, and plate gap.

Abstract: By way of Matlab software simulation, the relationship among shear stress and frequency, velocity, displacement and ER properties has been researched, the damper strength -- velocity, damper strength – drift properties of shear electrorheological fluid damper has been given, the law of damper strength with frequency, gap , diameter and electric field strength has been showed that damper strength is increasing with electric field strength, the biggest damper strength is 100kN, the key facters are velocity, drift, frequency, gap and etc.

Abstract: Magnetorheological (MR), Electrorheological (ER), and Ferrofluids are considered as a class of smart materials due to their novel behavior under an external stimulus such as a magnetic and electrical field. The behavior of these synthetic fluids offer techniques for achieving efficient heat and mass transfer, damping, drag reduction, wetting, fluidization, sealing, and more. Magnetorheological fluids are suspensions of non-colloidal, multi-domain and magnetically soft particles organic and aqueous liquids. Electrorheological fluids are suspensions of electrically polarizable particles dispersed in electrically insulating oil. Ferrofluids are known as magnetic liquids that are colloidal suspensions of ultrafine, single domain magnetic particles in either aqueous or non-aqueous liquids. In this review article a history of these fluids is given, together with a description of their synthesis in terms of stability and redisperibility and how it is understood in various parts of the science and technology. Then the structural changes and rheological properties of these smart fluids under an external stimulus together with a series of applications are presented.

Abstract: By means of mechanical properties test and structure observation， the relationship among electric field strength, polar molecule type, content on the Ni/TiO₂ group electrorheological fluid properties have been analyzed. It is found that with increasing electric field strength，the properties of electrorheological fluid increased for same composition ER fluid. Different type polar molecules have distinct effect. For same particle，with increasing polar molecule content，the property is increased, but there is a critical value . Polar molecule make particles chain of electrorheological fluid become strong，coarse and interweaved each other.

Abstract: This paper emphasis has researched the ER properties of Ni group core-shell nano particles modifier with Urea，SDBS and other polar molecule，analysis the relationship among ER properties and polar molecule type ，compound modifier under different electric field or magnetic field. It is found that the shear stress increasing with adding polar molecule, compound polar molecule modify can marked advance the properties of Ni group core-shell particles ER fluid.

Abstract: By means of structure analysis, mechanical properties test and microstructure observation，structure of Ni and Ni/TiO₂ group particles have been obtained, the relationship among partic_{Subscript textSubscript text}le diameter，electric field strength and shear ratio of the properties of Ni/TiO₂ group core-shell particles ER fluid have been researched. It has been found that with increasing particle diameter，the shear stress of ER fluid decreased, and with increasing shear ratio，the shear stress of ER fluid increased for same diameter particle and composition ER fluid. At same time, the smaller of particle diameter, the higher of ER properties such as shear stress, but there is a critical value for shear ratio, when shear ratio is larger than critical value, the properties of ER is nearly a value for same composition ER fluid. Particles chain of ER fluid under certain electric field is different with diversity Ni group Particles.

Abstract: By means of mechanical properties test， the relationship among particle size，electric field，magnetic field ,electromagnetic field and shear ratio on the Ni/TiO₂/Urea core-shell particles electrorheological fluid properties analyses. It is found that with increasing particle size， the property of electrorheological fluid decreased, and with increasing shear ratio the property of electrorheological fluid increased for same composition ER. At same time, the smaller of particle size, the higher of ER properties, but there is a critical value for shear ratio, the properties of ER is near value for same composition ER fluid. In magnetic field, the properties of ER showed a contrary result, the smaller of particle size, the lower of ER properties，and electromagnetic field make the properties increase.

Abstract: By means of mechanical properties test，the relationship among shear ratio, concentration and electric field, magnetic field ,electromagnetic field on the Ni/TiO2 group electrorheological fluid properties have been analyzed. It is found that with increasing shear ratio，the property of electrorheological fluid increased for same composition ER, but there is a critical value. With increasing concentration，the property of electrorheological fluid increased for same shear ratio. Coupling electromagnetic field makes the properties improve.

Abstract: By means of mechanical properties test and microstructure graph observation，the relationship of heat treatment temperature of core-shell Ni/TiO2 group particles with mechanical properties under different electric field has been researched .It is found that the FT-IR，XRD morphology of heat treatment at350°C is different from the one at100°C，the shear stress of same composition ER decreased with heat treatment temperature increasing. But the leakage current density of ER shows contrary result. That is because the leakage current density of ER decreased with the increasing heat treatment temperature.