Dynamics Experimental Research Of Capture Effect Of Electrorheological Fluids Based On Visualization

In recent years,the mechanism research of electrorheological effect have been the core of the electrorheological technology research content,which the results are very important to the formula design and engineering application of electrorheological materials.Although the yield stress of electrorheological materials reached kPa level,there is still a large gap to engineering practice which required to reach MPa level,so in order to accurate and comprehensive characterization the mechanism of the electrorheological effect still need further study.However,in the dynamic coupling(electric field and flow field)environment,studying the mechanism of the electrorheological effect through theoretical and experimental work based on the capture effect is new topic in the research field.In view of this,this paper establishes the dynamic coupling mathematical model of electrorheological suspensions,through the visualization of scientific experiments and simulation work to study "structure-force" of the electrorheological suspension dynamic coupling relationship,and seek the key factor based on capture effect of "structure-force" of the dynamic coupling strength.Firstly,based on the phenomenon of capture effect,combined the dielectric physics,rheology and electrodynamics with the traditional electrorheological fluid dynamic equations to analyzes main force suffered of the electrorheological particles which under the action of electric field and flow field coupling,and established dynamic model to characterize the "structure-force" of the electrorheological suspension of dynamic coupling relationship.Secondly,the movement rule of electrorheological particle of the electrorheological suspensions under the static and dynamic coupling field(electric field,flow field)has been studied through the numerical simulation using molecular dynamics method.In the static field,the electrorheological particles are clustered into a chain structure under the action of electrostatic polarizing force.However,in the dynamic coupling field,the electrorheological particles are captured by the chain-like network structure due to the influence of the capture force,causing the microstructure and mechanical properties of electrorheological suspensions has a dynamic coupling process.Finally,the microstructure evolution law of electrorheological suspensions in the static and dynamic coupling field(electric field,flow field)was studied by visualization experiments observation.Contrast analysis shows that there is no capture effect at the static field,and the dynamic coupling field due to the existence of the capture effect,the chain-network structure can capture the upstream free electrorheological particles from the control field,leading to solid-phase fraction ? ? density and the accumulation of electrorheological particles form N(microstructure deformation)of current variable suspension was changed so that make a big difference on the macro mechanical properties of electrorheological suspensions,which namely "structure-force" dynamic coupling.The results and the simulation was consistent.