Correlating Surface Shear Stress to Realistic Complex Terrain in Stable Atmospheric Boundary Layers

This paper presents computational surface shear stress results of Atmospheric Boundary Layer flow over a domain of complex terrain representative of Cincinnati, Ohio. The computational data, generated using a time averaged turbulence closure model, is used to assess flow separation and reattachment patterns, as well as the influence of canopies modelled as surface roughness on the flow behavior. The present data is combined with a different dataset generated by Large Eddy Simulation and is used to produce a correlation that relates the surface shear stress over a single hill within real repeated hills to the hill’s geometry. The correlation displays a linear pattern between the growth of a hill’s downstream slope and the shear stress difference over the slope. The correlation can also act as a validation tool for future data measured or computed over complex terrain, and as a relation that explains flow separation and reattachment patterns over complex terrain.