Theory and modeling of nonperturbative effects at high acoustic energy densities in thermoviscous acoustofluidics

TL;DR

This paper develops a comprehensive theoretical model for nonperturbative thermal and acoustic effects in microscale acoustofluidic devices, enabling accurate simulations for high-energy applications.

Contribution

It introduces an extended iterative model that captures nonlinear thermoviscous effects beyond standard perturbation theory.

Findings

Thermoacoustic streaming depends on temperature gradients caused by heating and convection.

The model predicts significant nonperturbative effects in high-energy acoustofluidic devices.

Simulations can now include nonlinear effects for better device design.

Abstract

A theoretical model of thermal boundary layers and acoustic heating in microscale acoustofluidic devices is presented. It includes effective boundary conditions allowing for simulations in three dimensions. The model is extended by an iterative scheme to incorporate nonlinear thermoviscous effects not captured by standard perturbation theory. The model predicts that the dominant nonperturbative effects in these devices are due to the dependency of thermoacoustic streaming on gradients in the steady temperature induced by a combination of internal frictional heating, external heating, and thermal convection. The model enables simulations in a nonperturbative regime relevant for design and fabrication of high-throughput acoustofluidic devices.