Are you interested mainly in erosion intensities on pump surfaces or are you heading for the prediction of pump geometry changes due to erosion and its backward effect on the flow conditions (and potentially pump performance). The first is simple, the second is possible with larger efforts.

Regards,

Dr. Th. Frank.

Thanks Thomas for your reply I am very interesting with both issues how you can help me with theses issues

Approach 1 (predicting erosion intensities on surfaces) is more or less straightforward in both ANSYS CFX and ANSYS Fluent.

1) Setup geometry and flow conditions

2) Predict the flow field

3) setup particle flow in the fluid flow field using the Lagrangian particle tracking approach

4) activate the build-in erosion model in the codes --> in the result the erosion intensity is shown in the CFD results on targeted wall surfaces

5) Done

Approach 2 is more difficult and there are situations where it is not reliably working. In this case the simulation is carried out in transient mode. The predicted erosion intensities are used to calculate a mesh displacement of near wall mesh elements (moving / deforming mesh approach in Fluent) in all timesteps. This finally leads to an erosion-induced change of the underlying geometry. This approach is substantially more computationally intensive in comparison to the 1st approach, where the calculation of erosion intensities is a kind of a postprocessing step to the steady-state flow calculation and already helps to identify erosion-endangered walls of the geometry.

Regards,

Dr. Th. Frank.

Many thanks Dr. Th. Frank for all information please could you send me more tutorials in ANSYS Fluent for both issues.

Regards,

Dr. Ahmed

corrosion in axial pumps is due to cavitation which is the presence of water vapor in the fluid which comes from strong pressure variations at the edges of the blades.

Thanks Benslafa for this comment

Are we talking about errosion (wear due to suspended solid particles in a fluid) or cavitational damage/wear to the pump blades?

Thank you very much Dr. Thomas, I wan erosion due to cavitational damage/wear to the pump blades and volute? thanks

Ok. Entirely different topic and it was not very clear from your original question. To my knowledge, there is of course the recommended Zwart-gerber-Belamri cavitation model in Fluent available, but no model which deduces from the correspondingly predicted flow field (pressure fluctuations, cavitation bubble collapse, strong vapor condensation rates, etc.) the resulting erosion damage due to cavitation. This is still a filed of ongoing research and no ready-to-use model has so far derived yet.

I have seen some work in literature, where people did a scale-resolving analysis + cavitation model. This is necessary to capture not only the purely mean pressure-driven cavitation effects, but the turbulence driven cavitation effects as well (depending on application), where smaller scale pressure fluctuations in turbulent eddies can lead to locally enhanced cavitation patterns as well. In the result they looked on the wall-orthogonal projection of regions with high condensation rates in order to identify wall regions of high cavitational material damage . The correspondance was quite astonishing, but more of qualitative nature.

Regards,

Dr. Th. Frank.

Many thanks Dr. Th. Frank.

Beat Regards

Dr. Ahmed Al-Obaidi