Study On The Hydrodynamic And Flow Field Characteristics Of An Ellipsoid In Maneuvering State

With the rapid development of modern science and technology,a large number of underwater vehicles are used in the battle for marine resources.As a typical representative of these submersibles,submarines have an irreplaceable role in modern marine warfare.In order to enable submarines to have efficient operations ability,superior maneuverability is one of its necessary conditions.The stability and controllability of the submarine in the maneuvering movement completely depend on the forces and moments it receives,and the hydrodynamic force received by the submarine is mainly concentrated in the main part of the hull of its ellipsoid shape.Therefore,the ellipsoid in the maneuvering state The study of sphere hydrodynamics and flow field is extremely important for the prediction of submarine maneuverability.In this paper,numerical simulation and experimental testing are used to study the hydrodynamic force,surface pressure and flow field characteristics of the ellipsoid under direct flight,oblique flight and dynamic motion.The numerical method uses the RANS equation combined with the SST turbulence model to simulate the ellipsoid in a maneuvering state,and mainly discusses the influence of speed,drift angle,and the amplitude and frequency of dynamic motion on the force and torque of the ellipsoid,and under the influence of these factors The changing law of the surface pressure;the test method realizes the ellipsoid motor movement by designing the horizontal motion mechanism platform,and uses the six-component balance,pressure sensor and other equipment to test the hydrodynamic force and surface pressure in the towing pool.The numerical method is verified by the test method.Accuracy,and analyze the influence of related variables on the hydrodynamic performance of the ellipsoid.Finally,the PIV test system is used to obtain the velocity field of the ellipsoid at different drift angles.Compared with the numerical method,it shows the flow separation phenomenon of the ellipsoid at different drift angles..Through the research of this article,we have mastered a set of ellipsoid numerical research methods under maneuvering conditions and a set of ellipsoid hydrodynamics and flow field test methods under maneuvering conditions.The research results show that under direct flight conditions,the resistance of the ellipsoid increases with the increase of speed,and under the conditions of oblique flight,the resistance decreases with the increase of drift angle.When the swing-bow coupling one motion,the hydrodynamic force and surface pressure peak and valley have a linear relationship with the amplitude and frequency,while in the coupled two motion,the relationship is nonlinear...