An optoacoustic point source for acoustic scale model measurements

Area of Science:

• Acoustics
• Laser Physics
• Fluid Dynamics

Background:

• Traditional acoustic sources can have mass, affecting scale model experiments.
• A need exists for a non-intrusive, point-like acoustic source for precise measurements.

Purpose of the Study:

• To propose and validate a novel massless acoustic source for scale model applications.
• To characterize the performance of this laser-induced plasma acoustic source.

Main Methods:

• A pulsed laser beam was focused to rapidly heat air, creating a plasma ball and a sonic impulse.
• The source's repeatability, frequency response, and directivity were experimentally measured.
• The impulse response of a rectangular space was determined using the developed source.

Main Results:

• The laser-generated source exhibited good repeatability, frequency response, and directivity, confirming its point-source characteristics.
• Measurements of a rectangular space's impulse response showed good agreement with predictions.
• The source effectively functions as a massless acoustic point source for scale model work.

Conclusions:

• A laser-induced plasma can serve as an effective massless acoustic point source.
• This method offers a viable tool for accurate acoustic measurements in scale models.
• The source's performance validates its application in studying the impulse response of enclosed spaces.