【作者】 张颖；

【导师】 刘晓宙；

【作者基本信息】 南京大学 ， 电子与通信工程（专业学位）， 2012， 硕士

【摘要】 本文研究了血液中的声流问题。声流是液体中的一种稳定流体,主要由于声振动的吸收产生。当声波传播过程中遇到像坚硬的平面、圆柱面或者球面时,就会导致声流的产生。在关于边界条件所引起的声流的研究中,气泡有着重要意义。由于气泡的可压缩性,它比相同条件下的坚硬物体表现出更有效的作为声流源的特性。气泡与边界的相互作用在各个领域都有着重要作用,因此通过研究此类声流的特性,可以更好的应用于各个领域的科研研究。前人通过引入镜像法,对硬边界附近的孤立气泡产生的剪应力作了理论研究,并给出了剪应力最大值的推导方法和其对声孔效应的意义。本文将在此基础上,将硬边界附近单气泡模型扩展到双边界情况,将其应用于声流的研究和所产生的剪应力的计算。在双边界情况下,通过数值模拟计算的方式,具体分析了声流待测点位置,血液的粘滞系数,气泡的半径等相关参数对剪应力的影响。本文中所建立的数学模型,可进一步拓展到软边界或弹性边界下的气泡模型,用于相关的研究。更多还原

【Abstract】 Acoustic streaming in blood is studied in this paper. Acoustic wave propagating in media has its linear momentum, which is equal to the acoustic power divided by the speed of sound. Acoustic streaming is a steady current flow in a fluid caused by the momentum transfer associated with the absorption of acoustic waves by the media. Acoustic streaming takes place in a viscous medium at the vicinity of a boundary such as planes, cylinders, or spheres. In case of that,bubbles play an important role. It is more effective as a sound current source than the hard object under the same conditions because of the compressibility of the bubbles. Interaction between bubble and the boundary has important effect in various fields so the study about this acoustic streaming is necessary for better research.Making use of the Doinikov and Bouakaz’s model, the aim of this study is to investigate acoustics streaming and its induced shear stress of a bubble near two rigid planes. Acoustics streaming conducted by micro-bubble near rigid plane is analyzed by expanding one-plane model to two-plane model. A numerical calculation of shear stress in the case of two-plane has been conducted which considers the effect of parameters like bubbles’positions, viscous coefficient of blood and the radius of bubble.The model built in this paper could be expanded to the micro-bubble in the case of soft boundary or elastic boundary.更多还原