Acoustically driven oscillatory flow fields in a cylindrical resonator at resonance

Area of Science:

• Acoustics
• Fluid Dynamics
• Computational Physics

Background:

• Acoustic waves in resonators are fundamental to many physical phenomena.
• Understanding acoustic streaming is crucial for applications in microfluidics and particle manipulation.

Purpose of the Study:

• To experimentally and numerically investigate the generation and development of acoustic waves in an air-filled cylindrical resonator.
• To analyze the formation of standing waves and acoustic streaming.
• To examine the influence of sound intensity and driving frequency on these phenomena.

Main Methods:

• Experimental measurements using piezo-resistive pressure transducers and hot-film anemometers.
• Numerical simulations using a high-fidelity scheme solving the compressible Navier-Stokes equations.
• Varying driving frequencies to produce standing waves and analyzing acoustic Reynolds numbers (20.0-60.0).

Main Results:

• Standing wave fields were successfully produced and characterized.
• Quasi-steady acoustic streaming patterns were observed and simulated.
• The flow regime was consistently laminar, with acoustic Reynolds numbers between 20.0 and 60.0.
• Sound intensity and driving frequency were shown to affect standing wave fields and streaming structures.

Conclusions:

• The study successfully characterized acoustic wave generation, standing wave formation, and acoustic streaming in a cylindrical resonator.
• Numerical simulations accurately reproduced experimental observations.
• The findings provide insights into the dynamics of sound fields and fluid flow interactions.