Shape Optimization And Flow Noise Analysis Of Stern Wing Artesian Inlet

Due to the advantages of small space occupation,high economy and low noise,many domestic scholars are optimizing the system and put forward many theoretical methods and innovative designs.The conventional artesian circulation system needs to set up an additional protrusion device in the hull of the vehicle,which will greatly increase the resistance of the ship.In this paper,the artesian circulation system is installed on the stern wing of the vehicle,and the self flow inlet is set at the upstream surface of the stern wing,so as to meet the cooling demand of the circulation system and reduce the ship’s resistance as much as possible.In this paper,the stern wing of an aircraft is taken as the research object,and the numerical simulation method is used to study and analyze the hydraulic performance of the artesian circulation system.Firstly,the model of flow field and sound field is introduced.Based on the actual demand,calculation of steady flow field by k-epsilon standard turbulence model,and the average flow velocity and inlet and outlet pressure drop of each scheme are obtained.In the acoustic calculation process,unsteady flow field calculation using DDES delayed separation vortex method.Finally,Solution of flow noise based on Lighthill acoustic analogy theory.Then,taking the stern wing of the aircraft as the research object,based on the finite volume method,the appropriate mesh generation method and boundary conditions are selected to verify the mesh independence.Then,the influence of the thickness of the stern wing,the shape of the inlet and the relative height of the artesian inlet on the flow rate of the artesian circulation system is analyzed.The pressure and velocity nephogram of artesian flow system under different schemes are studied,and the influence of parameter changes on the average velocity in the pipeline and the pressure difference between inlet and outlet is analyzed.Finally,the acoustic characteristics of stern wing are studied.In the rectangular,elliptical and parabolic entrance shape,the maximum flow scheme is selected to analyze the sound field.Firstly,cavity modal analysis is carried out to determine the first five cavity modal frequencies;Then,several monitoring points are set at different distances from the center of the stern wing to compare the total sound pressure level of each scheme;Finally,36 monitoring points are distributed in the XY,XZ and YZ planes of the stern wing to analyze the sound directivity.Combined with the calculation results of flow field and sound field,the influence of inlet shape on the flow rate and total sound pressure level of artesian flow pipeline is analyzed,and the final optimization scheme is selected to provide guidance for the follow-up optimization research.