Existence and properties of the logarithmic layer in oscillating flows

n this study, direct numerical simulations and wall-resolved large-eddy simulations are performed to test the logarithmic layer assumption in an oscillating boundary layer throughout the oscillation cycle. This is of interest for several industrial and environmental applications for which the wall-region is often bypassed in favour of a wall models to reduce computational time of numerical simulations of turbulent oscillating flows. Several configurations are tested by varying the Reynolds number, and the ratio between the water depth and the thickness of the Stokes boundary layer. In particular, we focus on how the existence of the logarithmic layer depends on the value of the Reynolds number, the depth to boundary layer thickness ratio, the phase, and in some cases, the oscillation cycle. Additionally, when the logarithmic layer exists, the universality of the von Karman constant and of the logarithmic layer intercept was thoroughly tested.