2306 ナノ粒子ER流体のせん断モードにおけるレオロジー・流れ特性(S42-2 複雑流体の流動現象(2),S42 複雑流体の流動現象)  [in Japanese] 2306 Rheological Properties and Flow Behavior of Nano-Particle ER fluid In Shear Flow Mode  [in Japanese]

The transient response of induced shear stress and the related flow behavior of an ER suspension containing nano-sized TiO2 particles have been investigated when it has been under the simultaneous stimulus of a constant DC or AC electric field and shear using a parallel rotary disk rheometer. As the DC electric field strength increases, the particles in the ER suspension form lamellar formations in the direction of shear, and sometimes agglomerate to form a non-uniform disturbed flow pattern inducing the violent fluctuation of the shear stress as time passes. As a result, the shear stress under DC electric field changes consistently with the morphology of the particle formations. While, the ER suspension under AC electric field (1kHz) is very stable to keep an almost constant shear stress, showing almost no morphology changes. The effects of shearing time, electric field strength, gap height between disk electrodes on the shear stress and the flow morphology are investigated experimentally.