Research On The Design And The Hydrodynamic Performance Of The Ship Flap Rudder

The rudder has a great influence on the maneuverability of the ship. Ship flap rudder is a kind of high lift rudder. It can effectively improve the performance of the ship turning. That's why it has caused the attention of designers in recent years. The research on the hydrodynamic of ship flap rudder mainly relies on the traditional theory, experience and related test. The design cycle is long and the cost is high, which brings inconvenience to the optimization design of ship flap rudder. The development of computational fluid dynamic prompted numerical simulation used in the study on the hydrodynamic of ship flap rudder which has important significance for the design of ship flap rudder.According to the size and design experience of a certain type of ship, this article designed the shape of the ship flap rudder. In this thesis, a general purpose CFD code, FLUENT, is used for studying the flap rudder hydrodynamic performance simulation calculation in open water conditions.,which focus on the variation of rudder force with rudder angle. The result is compared with the experiment result, and these two are matched well. As can be seen from the results, the rudder force increase with the main rudder angle and rudder angle increased, which is higher than that of streamlined rudder. Considering the actual situation, the hydrodynamic performance and the flow field distribution of a flap rudder behind the ship have been studied. And the influence of the ship flap rudder hydrodynamic performance on the ship under the sideslip angle has been studied, As can be seen from the results, the force of rudder behind the boat decreased than open water conditions affected by hull. The force of the left rudder is different from that of the right rudder. The rudder force will fall further when the ship is at the sideslip angle, which is higher than that of streamline rudder.The numerical simulation results of flap rudder force affected by hull are applied to the calculation of the turning radius of the ship. Calculation results show that the radius of gyration of the ship with flap rudder when the main rudder angle is 30 degrees and rudder angle 30 degrees is. 30 percent smaller than he radius of gyration of the ship with streamline rudder when the rudder angle is30 degrees.