Oscillatory flow of an incompressible couple stress fluid generated by the rotary oscillations of two concentric spheres

摘要

The paper deals with the oscillatory flow of an incompressible couple stress fluid generated by the rotary oscillations of two concentric spheres. A couple stress fluid fills the concentric region between the spheres and the two spheres are assumed to oscillate about a common diameter with the same frequency and with different angular speeds. The relevant components of stress tensor and couple stress tensor are obtained and the couple experienced by the spheres is evaluated. The couple is expressed in terms of two quantities K and K' and their variation is presented with respect to the couple stress parameter and frequency parameter through graphs.