Acta Ichthyologica et Piscatoria 12(2): 101-111, doi: 10.3750/AIP1982.12.2.10
Effects of mouth shape of conical netting constructions on properties of their resistance
expand article infoS. Dudko, J. Świniarski, Z. Przybyszewski, Z. Kwidziński, P. Nowakowski, H. Sendłak
Open Access
Abstract
Results of tests performed on 18 conical netting constructions, each construction being; a simplified model of the netting part of a trawl, are presented. The constructions were mounted on elliptical frames the oblateness (bl /a1) of which being 0.25; 0.50; 0.75; and 1.00; additionally, 5 constructions mounted on square frames were tested. The results point out the resistance coefficient Cx in the ellipse-based constructions to be independent of the ellipse oblateness within the range of 0.25- h 1.00. Additionally, energy expenditure per mouth area unit of four-walled netting constructions hauled in water was shown to be minimal with a circular and square mouth and to increase, with elliptical mouth, in a reversed proportion to the ellipse oblateness, bl /a1.