2統曳エビトロール網の模型実験

This study was carried out for the purpose of determining some physical characteristics of scale model of the balloon type double rigged shrimp trawl gear in the experimental tank. The net model was constructed in accordance with Dr. Tauti's similarity-law of fishing gear. The measurements were carried out both on the shapes and on the resistances in seven stages of towing velocity (V). For the convenience of discussions, the experimental values were converted into full scale values. Results were obtained as in the following: 1) Under the consideration of the physical characteristics of the gear efficiency, we have some parameters obtained as net mouth height (H), net mouth area (A), and wing tip distance (W). The above parameters are represented as in the following: H=2.7V^<-0.60> A=0.016V^<-0.52> W=2V+10.6 In the discussions of shrimp trawl gear efficiency, it is better for us to use the sweep area parameter of the gear (S_A), than to use the filtering volume (F_v). The sweep area is represented as in the following: S_A=14.5V-1.4 2) Concerning with the hydraulic resistance of the gear, the results were obtained as in the following: R_T=360V^<1.74> R_N=312V^<1.71> R_OB=44V^