(347a) Dynamics of Suspension of Anisometric Particles Via Stokesian Dynamics Simulation

Suspensions of non-spherical particles such as fibers, rods, spheroids, plates are commonly used in the material processing industries. The rheological properties of such suspension is influenced by the dynamics and orientation of the suspended particles which is affected by the hydrodynamic interactions. We have used the Stokesian Dynamics Simulation (Brady & Bossis, 1988) to study the dynamics of the suspension of anisometric particles by carrying out bounded simulation between plane parallel walls. The particles consisted of rigid spheres connected together by strong inter-particle forces. The simulation method was validated by comparing the period of rotation of a single rigid particle with that of the period of Jeffery's orbit of a spheroid of equivalent aspect ratio. Though the simulation method presented is for 3D, the dynamic simulations were carried out for monolayer of suspended particles undergoing shear and as pressure driven flow between two parallel walls following the approach of bounded simulation developed earlier (Singh & Nott, 2000). Though the 2D flow of anisometric particles appears to be restrictive there are many material processing applications where such flows are realized ( such as flow in thin die and narrow channels, film flow etc.). Moreover, from these simulations we hope to get insight of the microstructure and dynamics of such particles in homogeneous and non-homogeneous flows. Besides determining the shear and normal stresses, we have also studied the velocity and concentration profiles in simple shear as well as pressure driven flow in a channel.

References:

1. Brady J. F. and Bossis G., Stokesian Dynamics, Ann. Rev. Fluid Mech. 1988, 20 111-157.

2. Singh A. and Nott P. R., Normal stresses and microstructure in bounded sheared suspensions via Stokesian Dynamics simulations, J. Fluid Mech. 2000, 412, 279-301.