Visualization study on chain structure in electro-rheological fluids

The electrorheorogical (ER) effect is known as a phenomenon that shows reve rsible increase of apparent viscosity by applied electric field. The electr ic field induces the particle polarization, resulting in the chains between the electrodes. In this study, the ER fluids in the channel with two parallel electrodes we re visualized under the pressure flow. The laser light sheet and transparen t electrodes were used in the experimental apparatus to visualize the parti cles under 10wt% concentration. The particle chain structure in the channel was clearly visualized. Under higher voltage condition, particle layers we re formed at the neighbor of the electrodes. Processing the visualized imag es, the effects of the chain structure and the layer on the flow resistance were investigated.