摘要
The schlieren method is applied to visualizing the sound scattering of a cylinder immersed in the liquids. Images of the echoes, caused by normal and oblique incidence from a cylinder, are obtained for two kinds of liquids: (1) the liquid is composed of a transparent liquid; and (2) the liquid is composed of two non-mixable transparent liquids. It is found experimentally that the echo can be caused by the discontinaites in the shadow zone. This fact is utilized to demonstrate the locus of the helical surface wave creeping along the surface of the cylinder. For such cases the three-dimensional image can be described by this method and has not to use the system with special appliances and complex algorithm.
The schlieren method is applied to visualizing the sound scattering of a cylinder immersed in the liquids. Images of the echoes, caused by normal and oblique incidence from a cylinder, are obtained for two kinds of liquids: (1) the liquid is composed of a transparent liquid; and (2) the liquid is composed of two non-mixable transparent liquids. It is found experimentally that the echo can be caused by the discontinaites in the shadow zone. This fact is utilized to demonstrate the locus of the helical surface wave creeping along the surface of the cylinder. For such cases the three-dimensional image can be described by this method and has not to use the system with special appliances and complex algorithm.
基金
The projet is supported by National Natural Science Foundation of China
