Studies on mechanical matching calculation of low aspect ratio vertical cambered otter board in trawl system under heeling

Abstract

In this paper, for obtaining the influence of otter board heeling condition, a trawl system mechanical matching calculation model was established based on the equilibrium equation of otter board and tension equation of wrap, a widely used low aspect ratio vertical cambered otter board was selected, based on the hydrodynamic performance experiment data, combining with the data of Longteng vessel and four patch and big mesh size mid water trawl experiment results, mechanical calculation and analysis under heeling condition was conducted, the attack angle, warp tension and length, net depth, horizontal drag force and other trawl system parameters were obtained. The influences of otter board parameters under heeling condition were analyzed, the rules of mechanical matching calculation under heeling were summarized, it was proved that: warp tension and net depth increases with the increase of outward heeling angle, the range was separately 18145N-18225N and 51.2m-52.4m; decreases with the increase of inward heeling angle; the range was separately 49.6m-51.2m and 18069N-18145N.