Simulation of bottom trawl fishing gears. A simplified physical model

Computational modeling is a valuable complementary tool to assess behaviour of bottom trawl fishing gears. A simplified model of the gear that mainly affects to the net is proposed. The model is constrained to steady towing conditions, flat seabed and gear symmetry. Simulations proportionate a number of relevant outcomes like distribution of tensions at the warp, balance of forces at the otterboards or spread under different haul conditions such as depth or towing speed. Based on the above, the objective of the present study was to describe and implement the model and thus to predict the consequences of changing some gear components. This objective could have been fulfilled through extensive sea trials to cover all the different haul conditions of interest. Due to the high cost of such trials we choose to use sea trials carried out at two different bottom depths at which two different towing speeds were tested. Then we applied the computer-based simulation program to make a preliminary comparison with experimental results collected.