Numerical Investigations of Unsteady Flow in a Centrifugal Pump with a Vaned Diffuser
Journal article, 2013
Computational fluid dynamics (CFD) analyses were made to study the unsteady three-dimensional turbulence in the ERCOFTAC
centrifugal pump test case. The simulations were carried out using the OpenFOAM Open Source CFD software. The test case
consists of an unshrouded centrifugal impeller with seven blades and a radial vaned diffuser with 12 vanes. A large number of
measurements are available in the radial gap between the impeller and the diffuse, making this case ideal for validating numerical
methods. Results of steady and unsteady calculations of the flow in the pump are compared with the experimental ones, and four
different turbulent models are analyzed. The steady simulation uses the frozen rotor concept, while the unsteady simulation uses a
fully resolved sliding grid approach. The comparisons show that the unsteady numerical results accurately predict the unsteadiness
of the flow, demonstrating the validity and applicability of that methodology for unsteady incompressible turbomachinery flow
computations.The steady approach is less accurate, with an unphysical advection of the impeller wakes, but accurate enough for a
crude approximation. The different turbulence models predict the flow at the same level of accuracy, with slightly different results.
Turbomachinery
Sliding grid
Frozen rotor
CFD
OpenFOAM
Ercoftac Centrifugal Pump