Investigation of cause and magnitude of scale effect occurring in model experiments of fishing nets

摘要: In order to investigate the cause and magnitude of scale effect occurring in model experiments fishing nets, five pairs Nylon pyramid nets one pair PE ones which all two paired were equal each other factors determining their flow resistance, i. e., ratio d/l diameter d length l bars, angle f between adjacent attack q nettings water flow, wall area S different values prepared. Then, attached circular steel frame alternately resistances with shapes measured on sea ascribing no turbulent flows by using tension meter made a block bearing for experiment. All spreads out easily form cone at relatively low velocity showed resistance smaller little larger than them l, because filtration through meshes become easier especially l. But not spread sufficiently account small flexibility higher thicker twines. Therefore, difference bar or mesh size prototype are regarded effect. Especially influence may large significantly actual is decided much value that given so used this