尾流光学特性的数理模型及试验

Math-physical model of the optical characteristics of bubble film in ship wakes and the experiment

建立了气泡幕中气泡随半径分布规律的数学物理模型,从单个气泡对激光散射的影响推导出了气泡幕对激光的散射效应的数学表达式,并利用所得到的表达式在实验室条件下进行了相关计算。在气泡幕对激光散射的影响中,对激光偏振化特性的影响进行了区别计算,结果表明,激光的两种偏振化状态对气泡幕散射的影响从粗糙结构来看没有明显差异,但其精细结构有所不同。另外对不扩束和扩束两个条件下的计算明确显示出,扩束条件下散射光的强度是不扩束条件下的二倍以上,但二者的精细结构并没有可见的差别。在不同航速下测量了真实尾流不同几何部位的激光透射特性,测量结果与理论计算结果粗略一致。从透射光的相对强度来分析实验结果,可以认为自然光的影响是一个次要因素.

The math_physical model of bubble distribution in relation to bubble radius is predicted in this paper. Based on the effect on a single bubble, the mathematical equations for the scattering effect on the film of bubbles as derived. Calculation from the equations has been done with laboratory conditions. Polarizations are considered in the calculation of the scatted intensities respectively. Derivations show that, in the effect of polarization on scattering, there is little difference in rough structure and some differences in fine structure. Besides, calculation for normal and expanded beams reveals that the scattered intensity of expanded beam is above two times than one of normal bean but there is no visible difference in fine structure. Transmission of laser through differeot geometrical parts of real wakes at three rates is observed. The result is roughly consistent with the theoritical solution. Influence of natural light is less important from the point of relative intensity of transmission.