Direct and Large–Eddy Simulation of Turbulent Oscillatory Flow Through a Hexagonal Sphere Pack

In coastal engineering, the description of wave transmission and attenuation through rubble-mound breakwaters requires a model for the wave-induced flow inside the pore space of the breakwater [10, 16]. Extensive experimental investigations of oscillatory porous media flow were performed [3, 7, 15] in order to determine the coefficients of the unsteady Forchheimer equation [5] which relates the superficial velocity and the pressure gradient. These coefficients do not solely depend on the geometry, but they vary with time or frequency [2, 3, 15], raising doubts about the validity of this equation.