Calm Water Resistance Prediction and Navigation Posture Optimization of a New Unmanned Survey Catamaran
In order to obtain the resistance performance and economic navigation posture of a new unmanned survey catamaran,a calm water resistance simulation of this catamaran is conducted by model tests,the empirical formula method,and the computational fluid dynamics(CFD)method.Further,the CFD method is used to explore the influence of different longitudinal positions of the center of gravity on the hull and perimeter waveform,and a suitable installation position is selected for the multi-beam acoustic equipment.The results show that the CFD method can accurately predict the navigation posture and resistance at all speeds,while the empirical formula method is mainly suitable when the speed is low(FrΔ<1.5).At the speed of 4 and 6 kn,the economic navigation posture is at a tail tilt of 1.4°.At this time,there is a relatively stable high water level area between the pieces of about 0.3 to 0.5 times of vessel length from the stern,which can be used as a suitable installation position for multi-beam acoustic equipment.