A Flow in a Generic Centrifugal Pump

On this page there are results for a flow in a generic centrifugal pump. Only the one-bladed impeller with a short inlet pipe is modelled. The outlet boundary condition (pressure) is applied directly on a cylindrical surface near the impeller exit. The grid consists of two blocks in the impeller region. The second (innermost) block is used to prevent the singularity at the center of the channel. The grid topology causes a singularity on the outlet boundary, but this is considered to be less harmful. In the simulations a low-Reynolds-number turbulence model (k-w-SST) is applied. The total number of cells is about 750 000.

Surface grid of the pump

The bottom of the grid shows the grid topology.
The grid contains a singularity, which slowers the
convergence, but does not influence the final results.

This figure shows the pressure distribution
along the channel. A more accurate (eps)
figure can be obtained by clicking the image.







This figure shows the surface streamlines
in the rotating coordinate systems.
A considerably large region of reversed flow
occurs. This is also visualized using a surface,
which separates the reversed flow region.
The turbulence model does not have a large
effect on the reversed flow. A k-e produces almost
a same kind of flow structure. However, there are
some differences in the predicted head and efficiency
with different turbulence closures.





Streamlines and velocity magnitude (left),
and streamlines and radial velocity (right)
can be seen in this figure.
(Click for a large version).







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