The effect of slatted screens on waves

A linearised model is proposed for the transmission of waves through thin vertical porous barriers, where both the inertial and dominant quadratic drag effects are included. A boundary-value problem is developed in which linear boundary conditions holding along the length of the screen are derived from a pair of canonical wave problems, one including an exact geometric description of a slatted screen to determine an inertia coefficient and the other using a quadratic drag law to determine an equivalent linear drag coefficient. The model is then applied to a range of wave scattering and sloshing problems involving thin vertical slatted screens in various settings. In each case results are verified by comparison to the solution of a direct non-linear calculation where the effects of drag have been isolated. We show that the solution to our canonical problem provides a good approximation to the solution of each of the model problems.