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The results of hydrodynamic model experiment of otter board will have different degree of test deviation due to various factors such as processing method and structure simplification. In order to explore the influence mechanism of the processing materials of the otter board model on the hydrodynamic experiment, the double-slit rectangular curved otter board was selected as the research object. Based on the fluid-structure coupling algorithm combined with the flume tank model experiment, the influence on the hydrodynamic experiment and its structural response difference between the three 3D printing materials otter board and the traditional steel materials otter board was analyzed. The results show that there are significant differences in structural response and hydrodynamic performance between the traditional metal (Steel) and non-metal (ABS) models. With the increase of the angle of attack and the flow rate, the maximum deformation of the otter board increases, and the difference of lift coefficient and drag coefficient also increases. Due to the large elastic modulus and strong rigidity of PVC material, the structural response is close to that of metal material, so it has little influence on the results of hydrodynamic experiment. Based on the above results, PVC can be used as the 3D printing material to ensure the accuracy of the model and reduce the influence of the model material on the accuracy of the hydrodynamic experiment results. [ABSTRACT FROM AUTHOR]

The hydrodynamic model experiment results of trawling otter board often have different degrees of deviation due to various experimental factors such as Reynolds number and model scale ratio. To understand the Influence mechanism in the hydrodynamic model experiment of otter board, this paper selects vertical cambered V-Type otter board as the research object, bases on the flume tank model experiment combined with computational fluid dynamics (CFD) numerical simulation method, the hydrodynamic performance and flow field distribution were compared and analyzed, aims to explore the influence of model scale ratio, board thickness and model material on its hydrodynamic performance experiment. The results show that the change of model scale ratio has no significant effect on the curve shape of lift coefficient and drag coefficient, but excessive reduction of model scale ratio (20 ∶1) will lead to significant deviation of lift coefficient at the small angle of attack ( α < 30°). The change of the board thickness will lead to a significant change of the lift coefficient at the large angle of attack (α> 30°), while the influence on the drag coefficient mainly reflects on the small angle of attack ( α < 30°). Non-metallic material model is insufficient rigidity, and it is easy to produce certain displacement and deformation after obtaining stress in the flume tank model experiment process, which will cause the deviation of experimental results. Based on the above results, the model scale should be as large as possible to reduce the influence of model scale on the accuracy of experimental results. The structure stability of the model can be improved by increasing the board thickness, but the thickening range should not be more than double of the prototype. [ABSTRACT FROM AUTHOR]