Numerical Simulation Of The Settling Characteristics Of MR Fluids

As a new controllable intelligent material,magnetorheological fluid(MRF)has attracted more and more attention.It’s a liquid that can change its viscosity in a magnetic field.When it is in the external magnetic field,the viscosity of the liquid increases with the increase of the external magnetic field and decreases with the decrease of the external magnetic field.The effect of viscosity changing with the change of magnetic field is called magnetorheological fluid effect.Because of this excellent performance,MR fluid is widely used in many fields,such as automobile,military industry,construction and so on.This kind of magnetorheological effect of MRF depends on the uniform distribution of magnetic particles in MRF.Once the magnetic particles in MRF settle,the MRF effect will be greatly reduced until it disappears.Therefore,the settling stability of MRF has become an important attribute of MRF.Every research on the configuration method of MRF will measure the settling stability of MRF.However,at present,the measurement of the settlement stability of MRF depends on the experimental measurement,which is time-consuming and laborious.Especially at present,the configuration method of MR fluid is more and more perfect.The settling time of MR fluid prepared by the formula provided by some literatures is up to 3 months or even longer.It takes a long time to measure MR fluid by experimental method.In this paper,a numerical simulation method is proposed to simulate the settling process of MR fluid,and the relationship between the simulation time and the actual measurement time is explored.At present,the numerical simulation methods of MRF are mainly focused on the microstructure change of MRF in magnetic field,so in this paper,the existing numerical simulation methods of MRF microstructure are studied firstly,and then the dynamic simulation method of MRF settlement process is proposed based on these simulation methods.Secondly,according to the characteristics of the capacitance and inductance of MR fluid,two kinds of MR fluid settlement measuring devices are designed.After comparing the advantages and disadvantages of the two devices,the inductive settlement device is selected to measure the settling time of MR fluid.Finally,a variety of MRF samples are prepared and their actual settling rate and simulated settling rate are compared.Through comparison,it can be seen that the simulated settlement rate is much faster than the actual settlement rate.This shows that in addition to the factors considered in this paper,there are more factors that will affect the sedimentation process of MR fluid.However,when considering a single variable,it can be found that the ratio between simulation results and measurement results is relatively stable.This shows that it is feasible to use numerical simulation method to simulate the sedimentation process of MR fluid when more factors are considered.