Simulation of the three-dimensional turbulent flow inside a centrifugal fan impeller

Calculations of the three dimensional turbulent flow in a low pressure centrifugal fan impeller have been made using the multi-purpose,commercial CFD code: STAR-CD. Three different turbulence models were utilised: the standard κ - ε model, its RNG variant and one with Coriolis force modifications (or so called κ-ε-cm model). A systematic comparison between the calculated results and experimental data has been conducted and the results indicate that the general now characteristics such as the formation of jet-wakes and secondary vortical flow can be well predicted qualitatively. The calculated mean velocities as well as the turbulence kinetic energy are also in good quantitative agreement with the experimental data in most parts of the passage. The comparisons between the three different turbulence models show that, the κ-ε-cm turbulence model presents a substantial improvement on the prediction of turbulence kinetic energy. However, the RNG-based κ-ε model does not show any improvement over the standard model for this case.