ABSTRACT
The eigenspectrum for the planar Poiseuille flow of two immiscible Phan-Thien Tanner liquids is studied. The numerical method is to discretise spectrally employing the Chebyshev-tau method and the full set of eigenvalues are determined by the QZ-algorithm. The effects of variations in the fluid parameters are investigated and comparisons are made between the two-fluid and single fluid cases. The flow is found to be stable for the ranges of parameters investigated so far.