Within the demersal fishing industry there is increasing interest in the selection of the catch within the net, fuel reduction and lowering disturbances to the seabed. This has inspired the FishNetSIM project which aims to develop a modelling framework to assist in the traditional net design process. One of the main aims is to reduce fuel consumption by minimising the impact of dragging the nets.
The numerical modelling framework consists of coupled CFD and time-domain codes: CFD calculates the flow in the net and loads on the net, while time-domain calculates the deformations. The timedomain solver uses constraint dynamics (CoDy) to calculate the deformations.
Two sets of basin tests were performed to obtain validation data and prior to the start of the project, a full-scale trawler net was tested in the Seakeeping and Manoeuvring Basin. This resulted in visual results on net deformations and towing forces in the net. The second set of tests were performed in a saltwater basin at the Visserij Innovatiecentrum. Net sections and seabed friction were tested and this delivered data on towing forces on the net, flow profiles in the net sections and visual observations on the net sections.