Visualization Of Acoustic Waves Research Articles

Visualization of Acoustic Waves and Cavitation in Ultrasonic Water Flow

Visualization experiments were performed to examine whether acoustic bubbles play a role in ultrasonic water flow cleaning, as in convention cleaning with ultrasonic baths. Schlieren visualization confirmed the standing-wave-like acoustic field in ultrasonic water flow that collides with a glass surface. Backlight visualization showed that cavitation bubbles appear in the water flow spreading over the glass surface. These bubbles are found to oscillate in volume and move inside film flow and thus expected to play a role as active cleaning agents.

Visualization of Acoustic Standing Waves in a Closed Pipe Based on an Electronic Speckle Pattern Interferometer

We visualize acoustic standing waves supported in a closed-end square pipe based on an electronic speckle pattern interferometer and measure the wavelengths of the acoustic standing waves for undergraduate physics lab courses. Generating four acoustic standing waves of frequencies below the cutoff frequency governed by the physical dimensions of the pipe, we obtain the distribution of the irradiance difference of the speckle patterns in the interferogram and compare that to the result of a theoretical calculation. In addition, we estimate the wavelengths of the acoustic standing waves by measuring the distances between adjacent nodes of the speckle patterns. We show that the experimental results and the results of the theoretical calculations are in good agreement. This work facilitates the understanding of electronic speckle pattern interferometers and their applications in visualizations of acoustic waves for undergraduate physics laboratories.