Numerical simulation and experimental calculation of the shear velocity over regulary spaced hemispheres

In the study of flows over rough surfaces there is a vulnerable point in the determination of the shear velocity. The authors performed a numerical study whose results are the data enabling calculation of local shear velocity using the Turbulent Kinetic Energy approach. The employed numerical method is Large Eddy Simulation. The numerical results are validated by comparison with Particle Image Velocimetry experimental results. A different method, derived from the Turbulent Kinetic Energy approach, is also used to calculate shear velocity from the experimental results.