Temperature elevation, streaming, and self-action in sound beams

声束中的温度升高、流动和自作用

• 批准号: 08650063
• 负责人: KAMAKURA Tomoo
• 金额: $ 1.34万
• 依托单位: University of Electro-Communications
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1996
• 资助国家: 日本
• 起止时间: 1996 至 1997
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08650063/
• 关键词: Nonlinear Acoustic; Ultrasonic beam; Self-action; Acoustic streaming; Ultrasonic heating; 音波ビーム

When ultrasound is traveling down in a thermoviscous fluid, the sound energy is dissipated, and the fluid temperature in the beam is elevated. Inaddition of thus ultrasonic heating, bulk movement of the fluid is induced as acoustic streaming. The streaming carries away locally heated mass of the fluid downstream and reduces the temperature in the beam as cooling effect. Two physical phenomena of cooling effect by streaming and thermal self-action of sound beam in a viscous fluid have been investigated for the term of the present project. Sound energy losses due to viscosity and heat conduction in the fluid induce temperture elevation locally and streaming globally in the beams. The streaming carries forcibly away the heated mass of the medium and the temperature elevation is reduced. In a high viscous fluid, however, the streaming does not greatly build up because of the viscosity. As physical parameters such as sound speed depend on temperature in most fluids, sound beam changes its amplitude itself with irradiation time. A complicated but profitable numerical calculation scheme to solve simultaneously the basic hydrodyamic equations, heat transport equation, and wave equation, all the equations have individually temperature-dependent parameters, has been established using a finite difference method.

当超声波在热粘性流体中向下传播时，声能被耗散，并且束中的流体温度升高。除了超声波加热之外，流体的整体运动还被诱导为声流。流动带走下游局部受热的流体质量，并通过冷却作用降低梁中的温度。本项目期间研究了粘性流体中声束的流动冷却效应和热自作用这两种物理现象。由于流体中的粘度和热传导而导致的声能损失导致局部温度升高并在梁中全局流动。水流强行带走介质的加热质量，从而降低温度升高。然而，在高粘性流体中，由于粘性，流不会明显增加。由于声速等物理参数取决于大多数流体的温度，因此声束本身会随着照射时间而改变其振幅。使用有限差分法建立了一个复杂但有利可图的数值计算方案，可以同时求解基本流体动力学方程、热传输方程和波动方程，所有方程都具有单独的温度相关参数。

项目成果

Hai-Ying Huang: "Acoustic streaming and temperature elevation in focused Gaussian beams" J.Acoust.Soc.Jpn (E). 18・5. 247-252 (1997)

Hai-Ying Huang：“聚焦高斯光束中的声流和温度升高”J.Acoust.Soc.Jpn (E) 247-252 (1997)。

Hai-Ying Huang, Tomoo Kamakura, and Yoshiro Kumamtoto: "Acoustic streaming and Temperature elevation in focused Gaussian beams" J.Acoust.Soc.Jpn.(E). 18-5. 247-252 (1997)

Hai-Ying Huang、Tomoo Kamakura 和 Yoshiro Kumamtoto：“聚焦高斯光束中的声流和温度升高”J.Acoust.Soc.Jpn.(E)。

Hai-Ying Huang: "Acoustic streaming and temperature elevation in focused Gaussian beam" J.Acoust.Soc Jpn(E). 18(5). 247-252 (1997)

Hai-Ying Huang：“聚焦高斯光束中的声流和温度升高”J.Acoust.Soc Jpn(E)。