Numerical Simulation of Boundary-Driven Acoustic Streaming in Microfluidic Channels with Circular Cross-Sections

Abstract

While acoustic streaming patterns in microfluidic channels with rectangular cross-sections have been widely shown in the literature, boundary-driven streaming fields in non-rectangular channels have not been well studied. In this paper, a two-dimensional numerical model was developed to simulate the boundary-driven streaming fields on cross-sections of cylindrical fluid channels. Firstly, the linear acoustic pressure fields at the resonant frequencies were solved from the Helmholtz equation. Subsequently, the outer boundary-driven streaming fields in the bulk of fluid were modelled while using Nyborg’s limiting velocity method, of which the limiting velocity equations were extended to be applicable for cylindrical surfaces in this work. In particular, acoustic streaming fields in the primary (1, 0) mode were presented. The results are expected to be valuable to the study of basic physical aspects of microparticle acoustophoresis in microfluidic channels with circular cross-sections and the design of acoustofluidic devices for micromanipulation.

Numerical Study of Baroclinic Acoustic Streaming Phenomenon for Various Flow Parameters

“…Furthermore, the authors [36] showed that the temperature drop increases more than linearly with the increase of the temperature difference between the hot and cold surface. The authors of the work [37] have shown that streaming can occur not only in rectangular channels, but also in curved geometries.…”

Push/Pull Inequality Based High-Speed On-Chip Mixer Enhanced by Wettability

“…The important key words of this study are “flow in microfluidic channel”, “vibration input”, “surfactant”, and “experiment”. However, there are many studies discussing the flow in a microfluidic channel through the use of a “simulation” [ 7 , 11 , 31 , 35 , 36 , 37 , 38 , 39 , 40 , 41 ]. The closest study from the viewpoint of overlapping key words is that conducted by Kelder et al, who discussed the mathematical formulation of a fluid flow by considering the “vibration input” and the “surfactant” and showed various interesting “numerical simulations,” while focusing on the behavior of droplets appearing from the membrane rather than those of the fluid flow [ 31 ].…”

“…The closest study from the viewpoint of overlapping key words is that conducted by Kelder et al, who discussed the mathematical formulation of a fluid flow by considering the “vibration input” and the “surfactant” and showed various interesting “numerical simulations,” while focusing on the behavior of droplets appearing from the membrane rather than those of the fluid flow [ 31 ]. Lei et al discussed the “numerical simulation” of a boundary-driven acoustic streaming based “vibration input” in microfluidic channels and demonstrated a standing wave generated by a harmonic vibration of the boundary vibration input, although the main target was not focused on a fluid flow [ 41 ]. Based on a survey of conventional studies, no simulations indicated by the three key phrases “flow in a microfluidic channel”, “vibration input”, and “surfactant” have been conducted.…”

Ultrasonic Particle Manipulation in Glass Capillaries: A Concise Review

“…Circular cross-section glass capillaries have been widely used for acoustic concentration/focusing of microparticles. Typically, in such a device, a (1, 0) mode is generated in cross-section of the fluid channel where the primary and lateral acoustic radiation forces tend to move microparticles into the center of the channel [ 60 ]. An early relevant work was performed by Goddard and Kaduchak [ 61 ], who designed an acoustic microparticle focusing device that is composed of a circular cross-section glass capillary and a PZT, shown in Figure 9 A.…”