Abstract
This work investigates the two-dimensional orientation of a single fiber in a recirculating flow within a slot mounted on a wall of a parallel plate channel in order to elucidate the fiber orientation state in a recirculating flow as a fundamental study on anisotropic channel flow. The orientation state of fibers with aspect ratiora=5 and 100 at initial angle θ0=30·, 45· and 75· are simulated by computing the Jeffery's equation along three streamlines.
For large aspect-ratio fibers, a unique steady orientation state along each streamline can be obtained after several circulation independently of initial angles, and furthermore, the fibers almost completely align along the streamlines.
On the other hand, for small aspect-ratio fibers, almost steady orientation state can be observed along the only streamlines which are located within an inner region of the slot, however, the orientation state becomes unsteady as the main flow region is approached. Fibers lie obliquely to the streamlines even in almost steady orientation state within an inner region. This is also a very different result from that for large aspect-ratio fibers.
