Structures diffraction

When including a jetty or an offshore breakwater in the model the wave con­ditions shorewards of the structure are affected by diffraction.

The number of points behind the structure defines in how many points a Q-a curve should to be calculated to include the effect of diffraction. A larger num­ber may increase the accuracy, but will slow down the speed of the model.

The spreading factor describes the wave concentration parameter in deep water and is used in the diffraction calculations. A large value denotes a fairly narrow wave spectrum.