Dynamics Simulation And Experimental Research Of Electrorheological Fluids Under Non-uniform Electric Field

Electrorheological(ER) fluid is a type of new intelligent material whose rheological properties can be regulated by applied electric field. ER effect is an unusual phenomenon that the apparent viscosity of the ER fluids changed dramatically under external electric field. However, there are still no mature products relevant to ER materials on the market after decades of research. The reason mainly lies in the insufficient investigations on various mechanical properties of ER fluids and its mechanism in external electric field. In particular, researchers are unable to grasp the dynamic coupling relation between mechanical properties and sub-microscopic structure with multi-field coupling effect(flow field, electric field,shear field, et al.) in all directions.In this paper, it bases on the situation that the research of ER fluids dynamics under the non-uniform electric field is absented in the current. Therefore, the research work from theoretical and experimental studies has been carried out. The dynamics characteristics of ER fluids under non-uniform electric field are studied through a way of numerical simulation method combined with experimental study.Firstly, the main forces suffered of ER particle in the non-uniform electric field are respectively calculated and analyzed making use of the basic equations of the ER fluid dynamics. The micro-structure evolution of ER fluids is determined by these forces of ER particle under the non-uniform electric field. Then, making use of electrodynamics and hydromechanics theory, and combined with the basic control equations, it has established the dynamics model of ER fluids in the coupling field composed by external electric field and flow field(pressure gradient filed).Secondly, the transient movement of electrorheological particles under the static and dynamic non-uniform electric field has been investigated through the numerical simulation using the finite element method. Simultaneously, the dynamic coupling relation between mechanical properties and sub-microscopic structure in multi-field coupling(non-uniform electric field, flows field) has been researchedFinally, following the experimental requirements, the experimental ER fluid is configured, and its mechanical properties have been testing and analysis. It has carried out the visualization experiment study to the ER fluid dynamics under the non-uniform electric field by using the visualization experiment system. It has investigated the dynamic response of ER fluids in a single field(electric filed) andcoupling filed(electric filed, pressure gradient filed, et al.), and the impact of different factors on ER Effect.