The Research On Evaluation Of Radiated Noise Measurement In Marine Environment

The size of submarine radiated noise is an important indicator of submarine safety and combat capability.If the radiated noise of a submarine is too large,it will not only be easily detected by the enemy,but also lead to the increase of the background noise of the ship-borne sonar and the decrease of the detection ability.Therefore,it is of practical significance to study the radiated noise measurement technology.At present,the technology of radiated noise measurement has been developed maturely,but because most of our territorial waters are shallow sea areas,the environment of shallow sea areas is more complex.In the measurement of radiated noise,different ocean environmental parameters and measurement factors will bring errors to the measurement results.Therefore,this paper carries out research on these influencing factors,and carries out qualitative and quantitative analysis for the impact of different factors.In this paper,three types of radiated noise sources are modeled firstly.They are point source,complex source and volume distribution source.Nowadays,radiated noise sources are usually regarded as a point source in radiated noise measurement,but the point source does not conform to the acoustic field characteristics of submarines.Therefore,a volume distribution source model is established in this paper.The volume is obtained by using near-field acoustic holography based on equivalent source method.Equivalent source points of distributed sources;three commonly used measurement methods of radiated noise are studied,including mono-acoustic pressure hydrophone measurement method,acoustic pressure hydrophone array measurement method and single vector hydrophone measurement method;based on ray theory,combined with BELLHOP and virtual source method,ocean acoustic field environment is modeled and simulated,and the characteristics of acoustic pressure field and vector field in ocean waveguide are analyzed.On the basis of noise measurement method and ocean sound field,the influence of different ocean environmental parameters and measurement factors on the measurement of radiated noise is studied.The qualitative and quantitative analysis results are given for the influence of sea area depth,hydrophone and sound source location,hydrophone distribution distance and sound velocity profile on the measurement results.