Specular-reflection contributions to static and dynamic radiation forces on circular cylinders

Area of Science:

• Acoustics
• Fluid Dynamics
• Wave Physics

Background:

• Understanding acoustic radiation forces on objects in water is crucial.
• Objects can be highly reflecting with complex shapes and acoustic wavelengths smaller than their size.

Purpose of the Study:

• To analyze the specular contribution to oscillating acoustic radiation forces on a cylinder.
• To investigate the effects of modulated acoustic illumination on these forces.

Main Methods:

• Consideration of perfectly reflecting objects to gain insight into radiation forces.
• Analysis of specular contributions for an infinite circular cylinder under normal incidence.
• Utilizing double-sideband-suppressed carrier-modulated acoustic illumination.

Main Results:

• The oscillatory magnitude of the specular force decreases monotonically with increasing modulation frequency.
• The force's phase depends on the relative phase of the sidebands, which can be tuned.
• Ray analysis highlights the significance of near-backscattered rays with small impact parameters.

Conclusions:

• Specular contributions are significant for objects like aluminum cylinders in water.
• The findings provide insight into acoustic radiation forces on reflecting objects.
• The analysis is extended to analogous spherical reflectors.