Twin Rudder Performance Assessment According To The Body Gap to Improve the Controllability of a Yacht

摘要

The vessels type of multi-submerged body, have the hull form of twin body (catamaran) and triple body (trimaran) with their own rudder types in the generality of cases. In this paper, the study of flow pattern around twin rudder was carried out with various distances between two bodies and change angles of attack from 10 to 30 degree to predict the performance of the separation of flow. And the 2frame grey-level cross-correlation PIV method has been used to obtain the flow field information. Unlikely typical single rudder shape, distance between each rudder is a very essential design element. Generally, it is composed of thin external body shell relatively than single body shell combined. Besides, the optimum design is difficult from the flow change, complex phenomenon such as wave interference between two bodies as well as surrounding asymmetry flow change differently. But, it is trend that the practical use increases gradually by the advantage of excellent steerabililty, safety navigation, maneuverability running for pleasure in coastal areas and ocean etcAccordingly, in this experiment, turbulence flow was measured around of submerged twin rudder through PIV measurement in the circulating water channel. For the optimum design analyzing measure, distance change was 0.5C, 0.75C, 1.0C between two bodies and flow pattern variation with angles of attack was 10°, 20°, 30° available in this experiment. Reynolds number Re(=)1.5×104 based on the chord length (C= 100mm) has been applied during the whole experiments.