STUDY OF EFFECT OF VISCOSITY RESISTANCE IN ELECTROFHEOLOGICAL FLUID BY MICRO GRAVITY EXPERIMENTS

我们报道了在微重力实验中首次观察到由单分散介电粒子组成的单相电流变悬浮液中的电流变效应。设计了高灵敏度的电流变仪进行测量，结果表明，在微重力环境下，颗粒可以形成稳定的单相悬浮液，而传统电流变液通常需要悬浮液。实验发现，颗粒形成的柱状结构的尺寸超过了通常在两相ER流体中观察到的最大柱宽。采用有限元法对能量密度随应变的变化规律进行了数值计算，结果与实测数据吻合较好，特别是在低场区域。

We reported the first observation of electrorheological(ER) effect in a single phase ER suspension, comprising mono-dispersed dielectric particles, from a microgravity experiment. A highly sensitive electro-rheometer was designed for the measurements and the results show that, in the microgravity environment, the particles can form stable single phase suspension without a suspending liquid, which is usually necessary for the conventional ER fluid. It is found from the experiments that the size of the column structures formed by the particles exceeds the maximum column width usually observed in the two-phase ER fluids. Finite element method(FEM) was used to evaluate numerically the variation of the electric energy density with respect to the strain, and the results yield a good account of the measured data, especially in the low field region.