The Antarctic Krill Trawl Design And Performance Analysis

The Antarctic krill is the main feeding object among the Antarctic animals. It have rich resources in the Antarctic. The Antarctic krill resources widely distributed within the region covered most of the Antarctic waters. At present nearly 20 countries and regions have tested on the Antarctic krill, catching and large commercial development. And our country for the Antarctic krill development and production are still at initial stage. At present, it is important significance to develop the Antarctic krill for our country. This article through to the Antarctic krill trawl model test study optimizing the aft. It is important for development and production of the Antarctic krill in China. This test select of two middle trawling for mother type nets. The No.1net (Shanghai create companies use of pelagic fishery) and the No.2 net (Liao ning fishery group use krill trawl) in the basis of flume experimental for design and production model nets. This paper research contents include: (1) Two kinds of model nets for performance analysis ,includes different ether net port expansion of drag speed aft resistance changes, nets type situation; (2) Different as well as floating and gravitational forces performance with the influence of the aft; (3) Different fork length on the aft outline hydrodynamic influence, including hydrodynamic influence ether net port vertical expansion, resistance changes, and nets type change; (4) Under low drag speed adjustment methods, main test different halftone expansion to hydrodynamic drag layer and the aft influence; (5)Different assignments water adjust process gears (Mainly includes towing speed and drag the outline regulation), and the determination of gears drag water technology. (6)In optimizing the test, adjustment the proportion of the floating and gravitational (factor A , were taken 0.8, 1.0, 1.2), empty outline length (factors B, were taken 100m 130m, 160m), fork length (factors C were taken 35m, 45m, 55m), three major parameters.In this paper, the cistern of model test plan includes gears selection, gears conducted a total of 20 drag tests .Test results show that: Test results show that: (1)Net for the same roof with drag resistance with speed and L / S increases; Ethernet port height with tow speed and L / S decreased with the increase; Network of resistance and ether net port with a high degree change with the speed of change exponentially,significantly related;(2)The type of the No.2 net better than No.1 net. Ethernet port of No.1net fatter than No.1,s. And the nets body and matchs the outline need to be further optimized. Overall, the type of the No.1 net is not good. The type and body of No.2 net in the various network under tow speed it can maintain good stream line; (3)The No.2 with the change of energy consumption coefficients more smooth than the No.1, s. It is no influence to increase the aft guide nets hydrodynamic performance. After increase lining net, in 3.0 kn drag speed, without increasing the height of Ethernet port lining nets over 50%.Net increase of 27% with resistance.When extremely low L/S (0.2), the aft L/S energy consumption coefficient over 40% increase 0.44, the type of net is lower.(4) Optimization experiment results show: when L/S = 0.45, the optimal combination is A3B3C1; When L/S = 0.45, the optimal combination is A3B3C1; When L/S = 0.55, the optimal combination is A2B3C3.