热粘性流体中小颗粒在声场中的受力
Forces acting on a small particle in an acoustical field in a thermoviscous fluid
摘要：
我们提出了一个理论分析的声辐射力对一个单一的小颗粒，无论是热粘性流体液滴或热弹性固体颗粒，悬浮在一个粘性和导热的流体介质。我们的分析对粘性和热边界层厚度$δ_\mathrm{s}$和$δ_\mathrm{t}$相对于颗粒半径$a$的长度尺度没有限制，但是它假设颗粒与声波波长$λ$相比是小的。这是与声波和超声波从微米级颗粒散射有关的极限。对于尺寸与边界层相当或小于边界层的颗粒，热粘性理论导致声辐射力的深刻后果。我们不仅预测了比理想流体理论预期的大几个数量级的力，而且对于某些相关的材料选择，我们还发现了不同尺寸但相同颗粒上的声辐射力的符号变化。这种现象可能会被利用在处理亚微米大小的颗粒，如细菌和病毒在实验室芯片系统。
英文摘要：
We present a theoretical analysis of the acoustic radiation force on a single small particle, either a thermoviscous fluid droplet or a thermoelastic solid particle, suspended in a viscous and heat-conducting fluid medium. Our analysis places no restrictions on the length scales of the viscous and thermal boundary layer thicknesses $δ_\mathrm{s}$ and $δ_\mathrm{t}$ relative to the particle radius $a$, but it assumes the particle to be small in comparison to the acoustic wavelength $λ$. This is the limit relevant to scattering of sound and ultrasound waves from micrometer-sized particles. For particles of size comparable to or smaller than the boundary layers, the thermoviscous theory leads to profound consequences for the acoustic radiation force. Not only do we predict forces orders of magnitude larger than expected from ideal-fluid theory, but for certain relevant choices of materials, we also find a sign change in the acoustic radiation force on different-sized but otherwise identical particles. This phenomenon may possibly be exploited in handling of submicrometer-sized particles such as bacteria and vira in lab-on-a-chip systems.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
