Mixing Calculations in a Rotating Partitioned Pipe

We consider laminar mixing in a steady incompressible Newtonian uid. Through the use of particle tracking methods and analogous techniques applicable to material element vectors on a given velocity eld, residence time distributions, Poincare maps and material element deformations are computed; all of which are useful tools in determining the eecacy of a mixing system. We analyse the accuracy of using solenoidal ux-interpolating splines to represent the underlying velocity eld as a basis for determining mixing eeciencies. As a test case we use a rotating partitioned pipe mixer for which an approximate Stokes velocity eld is available. The Stokes representation provides us with a benchmark with which to assess the accuracy of the spline interpolants.