Numerical Simulation Of Sea Surface Characteristics Induced By Submerged Body Based On Viscous Flow CFD

Due to the uneven distribution of seawater parameters such as temperature and salinity,there is a large number of density stratified flow fields in the ocean.When the submerged body navigates around these stratified fluids,it will cause a huge disturbance to the original density stratification structure to stimulate the generation of internal waves.The generation of internal waves will interfere with the characteristics of the original sea surface flow field,and change the sea surface microwave scattering characteristics of the original flow field.This change in characteristics can be captured by synthetic aperture radar(SAR),thus enabling remote sensing.Can be used to detect underwater vehicles.In this paper,the characteristics of the sea surface characteristics of the wake surface induced by the submerged body are analyzed by CFD method.Firstly,using the Rankine Oviod model as the research object,the RNG k-s method is used to study the characteristics of the sea surface wake field induced during underwater navigation.The VOF multiphase flow model is used to capture the characteristics and characteristics of the sea surface flow field..The numerical simulation results are consistent with the Taylor Pool test results in qualitative and quantitative results.The feasibility and accuracy of the CFD method in studying the characteristics of the wake field during the motion of the underwater vehicle are verified.Then,this paper acquires the characteristics of sea surface flow field by means of remote sensing,and studies the methods and methods of obtaining the characteristics of sea surface flow field by synthetic aperture radar.The influence of backscattering characteristics of sea surface flow field on imaging is analyzed,and a simulation method of backscattering intensity of sea surface flow field based on backscattering mechanism is proposed.In this method,the sea surface flow field simulated by CFD is used as the input model.By obtaining the backscattering intensity on the sea surface grid unit in turn,the backscattering intensity map of the whole flow field with respect to a fixed observation angle is obtained.The simulation image and the SAR simulation image in the related literature are carried out,and the feasibility of the method applied to simulate the backscattering intensity map of the sea surface flow field is verified.Based on the above research,the numerical simulation and backscattering characteristics of the fixed-speed direct-floating wake field of submersible bodies in strong stratification are studied.The problem of the internal wave field induced by the submerged body and the backscattering characteristics of its free surface in the background of strong stratified fluid in hydrostatic water,based on the multi-phase flow model,the strong stratification is achieved by solving the three-dimensional and unsteady RANS equations for different speeds.The numerical simulation of the wake field of the submersible body is carried out to capture the waveform characteristics of the free surface,and the backscattering intensity of the wavefront is quantitatively analyzed according to the backscattering characteristics of the radar.Qualitative analysis of the influence of speed and radar direction on the backscattering characteristics of the sea surface flow field.Finally,combined with the JONSWAP wave spectrum,the simulation simulates the actual marine environment.The interaction between the wake field induced by the submarine body and the sea surface wind wave field induced by the fixed speed direct flight is studied.According to different sea conditions,the characteristics of the sea surface wake field and the relationship between its backscattering characteristics and sea state are studied when the submersible body depth and speed are fixed.