Contact/Supervisor: Prof. Nils Reidar B. Olsen

Sediments can cause damage on parts of hydraulic machinery when entering a hydropower plant. Typical problems are wear on guide vanes and/or blades in Francis turbines. The current project aims at investigating this process in more detail in the laboratory. The PIV rig at the Hydropower lab at Gløshaugen can be used together with a guide vane for a Francis turbine. The guide vane will be mounted in the flume and the water velocity field will be measured using standard PIV techniques. 

Afterwards, plastic particles will be added to the water, and the PIV instrumentation will be used to measure the paths of the plastic particles. The results will be post-processed together with the water velocity field to obtain the difference between water and plastic particle velocity fields. This is the drift-flux velocity field. This field is very important when using CFD to model sediment transport by an Eulerian method, as this is one of the computed parameters of the numerical model. The laboratory data from the current project can thereby be used to verify the CFD model.

Another method to verify the CFD model is to paint the guide vane with a soft paint before starting the experiment with plastic particles. The particles will then erode some of the paint. The location of the paint erosion can be measured over time and compared with the results from the numerical model.