Flow of “stress power-law” fluids between parallel rotating discs with distinct axes

摘要: Abstract The problem of flow between parallel rotating discs with distinct axes corresponds to the case in an orthogonal rheometer and has been studied extensively for different fluids since instrument׳s inception. All prior studies presume a constitutive prescription fluid stress terms kinematical variables. In this paper, we approach from perspective, i.e., specification symmetric part velocity gradient Cauchy stress. Such ensures that boundary conditions can be incorporated manner quite faithful real world experiments instrument. Interestingly, choice condition is critical solvability creeping/Stokes flow. When no-slip enforced at boundaries, depending on model parameters offset, response show non-uniqueness or unsolvability, features which are absent conventional specification. Moreover, prescribed values stress, indeterminate. We also record particular given “stress power-law” fluid; one cannot attained by power-law fluids.