Design of trawl otter boards using computational fluid dynamics

Computational fluid dynamics (CFD) analysis was conducted for a biplane-type otter board model to validate the use of CFD analysis in designing otter boards. In the base mode (aspect ratio 3.0, camber ratio 15%, gap-chord ratio 0.91, and stagger angle 30°), CFD analysis results show a maximum lift coefficient value of 1.65 for angle of attack 17.5°, which is in agreement with results of the flume tank experiment (CLmax = 1.64 when α = 20°) under the same conditions. In addition, the streamline and separation zones around the otter board were visualized and compared to the results from past tank experiment studies. CFD analysis results showed patterns similar to the experimental results, and the details of flow with a trailing vortex were confirmed. We concluded that CFD analysis is useful in the designing and development of otter boards.