Dynamics Simulation And Experimental Research Of Electrorheological Fluids Under The Micro-scale

Electrorheological(ER)fluid is a type of intelligent material whose rheological properties can change rapidly and reversibly under the action of electric field,it has broad prospects in the respect of the practical engineering applications,although the yield stress of the new type ER materials had great enhancement in current,there are still no mature products relevant to ER materials approaching the market.The reason mainly lies in the insufficient investigation on the ER effect mechanism and the dynamic characteristics of ER fluids under the action of the coupling field.Found on the research progress of ER fluids,both the scales of time and space to represent ER effect are very small,there are some characteristics of micro-scale flow in its flow process.According to this characteristics,the flow of ER fluids is regarded as micro-scale flow in this paper,the research work from theoretical and experimental studies has been carried out,the dynamic characteristics of ER fluids under the action of the dynamic coupling field(electric field and poiseuille flow field)are researched through a method of numerical simulation combined with experiment.The purpose is that researching deeply ER effect mechanism and improving the formula design of ER materials.This main work is as follows:Firstly,based on the theoretical model of ER effect,the main forces of the dielectric particles are analyzed and calculated by considering the influence of some micro-scale factors of the electrokinetic effect and the surface force,ER fluid dynamic equation under the micro-scale is established according to this,and ER fluid dynamic coupling model under the micro-scale is established by combined ER fluid control equation according to some theories of fluid dynamics and electrodynamics.Secondly,the dynamic rule of the dielectric particles under the actions of the static field and the dynamic coupling field has been numerical simulated by using the dissipative particle dynamics method.And the effect of surface force on the submicroscopic structure of ER fluid under the static field and the effect of electroviscous effect on the flow velocity of ER fluid under the dynamic coupling field have been researched.Finally,the experimental ER fluid was prepared by combined the dimethicone and the anion exchange resin,and its rheology properties have been tested.The changes process of submicroscopic structure of the ER fluid under the static field and the dynamic characteristics of the ER fluid under the dynamic coupling field have been observed respectively through the experimental stand,and the effect of electric field intensity,flow velocity and channel height on the ER effect have been researched.The micro-scale flow characteristics exhibited by the electroosmotic effect under the static field and the wall slip under the dynamic field were found in the experimental research.