Research On The Fluid Properties Of Concentrated Fiber Suspensions

In this thesis, the application and research history of fiber suspensions are reviewed, as well as its recent research process. The thesis also expatiates upon the slender-body theory which is widely used under low Reynolds number conditions.Based on the slender-body theory and the relevant concept of Molecule Dynamics Simulation, the numerical model which was used to simulate the interaction between two contact fibers is extended to systems of large amount of rod-like fibers. A new theoretical model of concentrated fiber suspensions involving both hydrodynamic and contact forces is presented. Upon the simplification of this model under Stokes flow conditions, we simulate numerically the 2D concentrated fiber suspensions in simple shear flow, and derive the structures and properties of those suspensions, successfully. Finally, the influence of shear rate and the number density and aspect ratio of the fibers are discussed.In this simulation, it is the first time to take both of the hydrodynamic interaction and fiber-fiber collision into consideration. An Event-driven (collision-driven) algorithm for rod-like particle system is proposed to expediate the calculation of collisions.