Fin-hull Adaptation And Low Speed Control Strategy Research

There are several years since the anti-rolling fin was invented,but the basic theory of anti-rolling fin,such as hydrodynamic modeling of the fin,flow field simulation,fluid dynamics,the parameter selection and so on all are still in the stage of exploring and perfecting.The hydrodynamic characteristic of the fin and the hydrodynamic performance of the ship have been conducted by many scholars in recent years,however,they tend to ignore the fin working on the hull,the influence of the interaction between velocity field of them cannot be neglected,there are many differences between the hydrodynamic characteristics of the fin under the condition of open water and the hydrodynamic characteristics of the fin with the constraints of hull,inevitably,the differences will increase or decrease the performance of the fin.There are many researches are conducted between the two pairs of fins,they are mainly concentrated in the optimal installation position,the distribution of area,hydrodynamic calculation,etc.,the exploration of such issues has been fruitful,there are many have even applied the in the design of the stabilizer equipment,but there are many problems to be solved,thus to explore the suitability of the fin-hull is of great significance.On the other hand,under the condition of low speed flow,the traditional fin control method is not suitable for this condition,there is no good control method able to significantly improve the performance of the fin in the low speed situation,therefore,to explore control strategy of the fin on the condition of low speed has important significance.In this paper,on the basis of the study of the anti-rolling fins in the open water and aiming at the actual engineering application,the research with the fins and hull as a research object is carried on.The main content of the research include: first,this paper summarizes the development condition of the research object in the domestic and foreign;Secondly,the simulation software FLUENT and the MATLAB are used to study influence between the anti-rolling fins and hull at low speed and high speed condition,and the pool experiment is used to verify the reliability of the simulation results;Then,the simulation software FLUENT and the MATLAB are used to study the interaction between the two pairs of fins on the hull in the case of static and dynamic,and genetic algorithm is used to design the optimum spacing between two pairs of fins’ system;Finally,interference model of the wave and lift model of low-speed anti-rolling fins are set up,and the fractional order PID controller is designed by using artificial colony algorithm,low speed control system simulations are done and the damping effect is compared between traditional PID controller and fractional order PIDcontroller.