Research On Active And Passive Flow Control And Noise Reduction Technology Based On Jet And Groove

The radiated noise of underwater vehicles is an important indicator of the performance of naval equipment.If the radiated noise of underwater vehicles becomes lower,the undewater vehicles will have stronger concealment,stronger combat capablities and survivability.Hydrodynamic noise,as the main source of radiated noise of underwater vehicles during high-speed navigation,has received extensive attention in recent years.The current research on hydrodynamic noise control of underwater vehicles only focuses on online optimization and local corner filling,and does not involve too much flow control technology.This paper proposes a method to reduce the hydrodynamic noise of underwater vehicles based on jet and groove flow control technology.Jet and groove devices are added at the junction of Suboff podium shell and hull to control the flow and reduce the hydrodynamic noise of underwater vehicles.In response to the requirements for the control of the flow field and hydrodynamic noise at the junction of the main appendages of the underwater vehicle,this article carried out research work using jets and grooves as flow control technology to suppress the vortex and pulsation at the junction of the main appendages of the underwater vehicle Pressure intensity,the purpose of reducing the hydrodynamic noise of underwater vehicles;by constructing an accurate model of unsteady flow field and pulsating pressure,carrying out theoretical analysis,numerical calculation and experimental verification,analyzing before and after adding jet and groove vortex generators,The fluid flow state after the flow passes through the junction of the main appendages of the underwater vehicle,the mechanism of noise generation is summarized,the effect of different characteristic parameters of jet and grooved vortex generators on hydrodynamic noise is studied,and the amount of noise reduction by each characteristic parameter is summarized To determine the structure of the jet and groove with the best noise reduction effect.The study found that the jet and groove vortex generators can suppress the generation of horseshoe vortices,reduce the vortex and pulsating pressure intensity at the junction of the main appendages of the underwater vehicle,delay the transition of the transition zone,reduce the resistance of the model,and reduce the horseshoe vortex.The low-frequency line spectrum noise generated by the vortex excitation hull.Finally,the original model,the groove vortex generator model,the jet vortex generator model and a set of complete fluidic system are designed.Then having a hydrodynamic noise measurement test in water cave.The results show that the active and passive flow control technology based on jet and groove proposed in this paper achieves the goal of suppressing vorticity control and fluctuating pressure intensity,and the model test verifies that the hydrodynamic noise reduction effect reaches 5d B or above with a frequency of 10Hz-2k Hz.The results of this paper can provide reference for the hydrodynamic noise control of underwater vehicles in the future.