Experimental Study On Light Scattering Spatial Spectrum Distribution Of The Ship Wake

The detecting system based on the light scattering characteristics of the ship wake will be used broadly in the future. Based on the understanding of the characteristics of the ship wakes and the distribution characteristics of bubbles and particles in the sea, the spatial spectrum distribution of the near-forward light scattering in the ship wakes are studied with Mie-theory in this paper, and the results indicate that the FWHM of the spatial spectrum distribution could reflect the information of the ship and its wake. Then the Gauss fit used in the experiment and the actual detecting system is presented. And many experiments are done to study the variation rule of the light scattering spectrum distribution with the Gauss fit. The experimental results indicate that the FWHM and the peak value of the bubble scattered spectrum distribution are decreasing as the dimension and density of the particles increasing. Meanwhile, it indicates that the FWHM is more sensitive to the variation of the ship wake (bubble's size and density) than that of the peak value.The turbulence and the vortex induced by propeller could influence the light scattering spatial spectrum distribution of the ship wake. So the characteristic of turbulence is also studied in this paper. The results indicate that the FWHM of the bubble scattered spectrum distribution with presence of turbulence is smaller than that out of turbulence, and the influence on FWHM of the bubble scattered spectrum distribution induced by turbulence is mild than that by particulate substance.