Hydrodynamic characteristics of a hyper-lift otter board with wing-end plates
2015
Shen, X. (Tokyo University of Marine Science and Technology, Minato, Tokyo (Japan). Graduate School of Marine Science and Technology) | Hu, F. | Kumazawa, T. | Shiode, D. | Tokai, T.
The paper investigates the hydrodynamic characteristics of a hyper-lift trawl door (HLTD), which consists of a cambered plate with two wing-end plates with the leading edge modified into an airfoil shape. Flume experiments were carried out in a circulating water tank using models having a wing area of 625 square cm and an aspect ratio of 1.0 at camber ratios of 15, 20, and 25 %. To determine the effect of the wing-end plates, models with different size of wing-end plates were tested. Moreover, the effect of heel angle on the hydrodynamic characteristics of the HLTD was also investigated. We concluded that the size of the wing-end plate was significant for h/c = 0.10 (h width of the wing-end plate, c chord length of cambered plate), and the maximum lift coefficients of HLTDs with camber ratios of 15, 20 and 25 % were 2.19, 2.38, and 2.48, respectively, at an attack of angle of 38deg. In addition, our findings showed that the effect of the heel angle was very small on the lift, drag and moment coefficients of a HLTD when it slants at heel angles from -20deg to 20deg during trawling.
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