On the Effect of Water Flow Speed to Hydrodynamic Resistance Force of Gillnet; Model Net Experiments in the Flume Tank

Abstract

When gillnet is operated in the sea its will encounter the effects of seawater current and tidal movements. The shape and construction of the gillnet will be effected by the direction and flow speed of the seawater current. When the current is strong enough the gillnet shape could be changing, falling down or even roll up. Eventually it will results on the net broken and the failure of fish catching.These net disorders could be caused due to the composition of the gillnet components was inappropriately fixed. The proper allotment of floats and sinkers could results fine gillnet endurance toward current since the buoyancy and sinking forces having significant role in maintaining the gillnet stability. This research is dealing with the experimental on the model net, float, and sinker in the flume tank to estimate the effects of flow speed toward hydrodynamic net resistance. The results of the laboratory experiments will be converted to calculate the optimum allotment of floats and sinkers fixed in the prototype of commercial gillnet.