Simulations with a 3D active absorption method in a numerical wave tank

The absorption of waves along the lateral boundaries of a wave tank is a challenging problem in physical facilities as well as in numerical models. One method applicable to both types of facilities is to use active wave absorption. Active wave absorption using a wavemaker is a well-known technique in wave flume (2D) tests, and the 2D technique can also be used as a quasi-3D absorption method in a numerical wave tank. A recently developed method for 3D active wave absorption in a wave tank using a number of wavemakers for the absorption has been implemented into a numerical wave tank model based on a boundary element formulation. In the present paper some numerical tests are made in order to assess the accuracy of the method. The numerical tests involve absorption of obliquely incident waves on the active wave absorber and simultaneous generation and active absorption of waves in a 3D numerical wave tank. The numerical results show that the 3D active absorption method works as expected and that it is superior to a quasi-3D method (based on a traditional 2D active absorption method).