Dynamics of semi‐flexible and breakable fibers under Poiseuille flow

Abstract

In the processing of fiber-reinforced polymer composites, especially in injection molding, the fiber's orientation, length, and distribution vary depending on the location of the channel flow and its properties, which affects the performance of final products. To investigate the intricate behavior of fiber suspensions under Poiseuille flow, we used the hybrid simulation approach, multiparticle collision dynamicsmolecular dynamics (MPC-MD), which takes hydrodynamic interactions and fiber properties (strength, flexibility) into account. For non-breakable and rodlike fibers, fibers align well along the flow direction while showing more alignment near the wall. As fiber becomes breakable and/or flexible, the length and orientation of fibers strongly depend on their properties. The interesting phenomenon is specifically seen for breakable and semiflexible fibers, where the orientation of the fiber exhibits non-monotonic behavior depending on the flow rate. This complex behavior highlights the importance of comprehending the dynamics of many types of fibers and necessitates research into the best conditions for injection molding.

Lock-key microfluidics: simulating nematic colloid advection along wavy-walled channels

“…To simulate colloids in a flowing and thermally fluctuating nematic liquid crystal confined within a complex channel, a multi-particle collision dynamics (MPCD) algorithm is used. [39][40][41][42] MPCD has been employed to simulate reactiondiffusion dynamics, 43,44 electrophoresis, 45,46 thermophoresis, 47 swimmers, [48][49][50] polymers, [51][52][53][54] colloidal suspensions, 55,56 binary mixtures, 57 viscoelastic fluids, 58 ferrofluids, 59,60 and dense stellar systems. [61][62][63] Most relevantly, MPCD has been used to simulate nematic liquid crystals.…”