[Ste3D]

Hi,

I'm modelling a river power plant including weir and turbine passage. The turbine runners itselfe are not represented in the model, however I account for the turbine and flow distributor resistance using baffle losses. The volume flow rates through the turbines are correct, but I observe a strange pattern regarding flow velocities resulting in a very inhomogeneous flow field, which cannot be not be observed by measurements. The figure shows the model flow velocities 12m downstream of the "turbine".


Figure of flow velocities


has someone observed a similar pattern and might have an explanation for it? I use the RNG turbulence model. Grid resolution is 0.5m (x,y,z) with 0.25m conforming mesh to blocked volume. Already tried without conforming mesh (0.25m for whole tubine passage) thats not the reason for the observed pattern.


Thanks for your help!