Flow of viscoelastic fluids between two eccentric cylinders with the pressure gradient or the cylinders themselves oscillating sinusoidally is numerically calculated by the finite difference method. Authors compare numerical results of flow enhancement, periodic flow rate and periodic velocity distribution with experimental data. Results are as follows :
1) Flow enhancement decreases with increasing frequency under both modes of oscillation
2) When the pressure gradient was oscillated, the mean pressure gradient value that brings about maximum flow enhancement decreased with increasing eccentricity. However, the maximum value itself remains the same for all values of eccentricity.
3) Flow enhancement due to oscillating tube decreases with increasing eccentricity.
4) Effects of oscillation frequency on flow rate time profile was clarified.
5) Numerically computed flow enhancement was in qualitative agreement with the authors' previous expermental results.
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