Research On Optimization Design Of Superstructure Of The Ship Based On The Aerodynamics

By using the conventional ship hangar sharp edge shape modification,the characteristics of the superstructure wake is altered,so as to the negative impact of wake on the landing of the shipboard helicopter is effectively weaken.First of all,based on the comparison of the experiment data and numerical simulation result for the same frigate model,the pros and cons of the pressure based solver and density based solver were discussed,and based on which the proper solver was selected.In this thesis,the scale effect of the ship was also studied by utilizing the numerical simulation.By numerically simulating the flow field of different hangar shape of ship,a large zone of flow separation at the downstream of the hangar was observed for different cases.There is a series of vertical flow structure near the hangar wall,which appears steep downwash effect,and the horseshoe vortex is formed over the flight deck.The ship superstructure and hangar shape was locally modified to control the flow field over the deck surface.Form the comparison of the numerical results,it was found that,the quality of flow field can be effectively improved by amending the hangar sharp trailing edge to smooth curved shape.The influence of the different downwash on flow field of the landing point which caused by the hangar trailing edge under the different radius of curvature and other shape models was summarized in this thesis.The influence of the Re number was also analyzed in depth in this thesis for a series of geometrical similar frigate models by applying the numerical method.