Study of the dynamics of submerged supple nets (applications to trawls)

An iterative method is presented for determining the dynamic behaviour of submerged supple nets such as trawls. The flexible structure is modelised by a set of rigid bars. The junction points between the rigid elements are assumed to be rotoïdal links. The hydrodynamic forces, applied to each bar, are determined by combining and generalizing the Landweber and Morison hypothesis. All temporal derivative operators are approached by finite difference schemes. Some examples of the dynamic behaviour of a particular trawl are presented and qualitatively compared with flume tank observations.