Department of Mechanical Engineering and Applied Mechanics, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
Phys Rev Lett. 2012 Feb 3;108(5):058302. doi: 10.1103/PhysRevLett.108.058302. Epub 2012 Jan 31.
The shape dynamics of soft, elastic particles in an unbounded simple shear flow is investigated theoretically under Stokes flow conditions. Three types of motion-steady-state, trembling, and tumbling-are predicted, depending on the shear rate, elastic shear modulus, and initial particle shape. The steady-state motion is found to be always stable. In addition, the existence of a trembling regime is documented for the first time in nonvesicle systems, and a complete phase diagram is developed. The rheological properties of dilute suspensions of such soft particles generally exhibit shear-thinning behavior and can even display negative intrinsic viscosity for sufficiently soft particles.
在无界简单剪切流中，研究了软弹性粒子在斯托克斯流条件下的形状动力学。根据剪切速率、弹性剪切模量和初始粒子形状，预测了三种运动状态：稳态、颤动和翻滚。发现稳态运动始终稳定。此外，首次在非囊泡系统中记录到颤动状态，并开发了完整的相图。这种软粒子稀悬浮液的流变性质通常表现出剪切变稀行为，对于足够软的粒子甚至可以表现出负的固有粘度。
