Flow over periodic hills

Flow over periodic hills

The flow over periodic hills is a common test case for the validation of numerical flow simulations (see ERCOFTAC test case Nr. 81). The numerical prediction is quite difficult, since flow separation and reattachment are not fixed in space and time due to the smooth geometry. Furthermore, the separated and fully three-dimensional flow from the previous hill impinges the next hill and results in very complex flow features including turbulent splashing, Taylor-Görtler vortices and a very thin shear layer with developing Kelvin-Helmholtz instabilities. The complex dynamic of the flow can easily be seen in the instantaneous images on the right side. By combining the experimental capabilities of the partners of the consortium time-resolved planar and volumetric measurements were performed and will be analyzed in the future to help to enhance the understanding of the flow and its numerical simulation. Of special interest is the thin shear layer at the hill top. Using the advanced single-pixel ensemble-correlation method and particle tracking the steep gradient can be resolved.


Funded by the European Community (FP7/2007-2013) under grant agreement No. 265695.


Partner: TU Delft (Prof. Scarano), DLR Göttingen (Dr. Schröder),
             LaVision (Dr. Michaelis), TU München (Prof. Manhart)


Contacts: Dr. Christian Cierpka