Paper presented at the 5th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, South Africa, 1-4 July, 2007.
In this paper a computational, time-accurate analysis of a
single-blade pump, whose flow system is characterized by
highly oscillatory behavior, is presented. The study lays bare
the immanent challenges present in applying CFD to such
complex flow systems. Four time-accurate simulations with different
modeling choices are completed in order to reveal the
computational flow system's sensitivities to such decisions and
obtain reliable performance predictions for experimental comparison.
The time-accurate simulations consistently overpredicted
the hydrodynamic performance according to expectations,
but demonstrated strong dependency on particular CFD
aspects: The strictness of the numerical convergence and the
changes in the inflow and outflow configurations have a considerable
effect on the system's flow behavior. Elevated levels
of uncertainty also accompany the transient simulations.
