Subsonic leaky Rayleigh waves at liquid-solid interfaces

Area of Science:

• Acoustics and Solid Mechanics
• Materials Science
• Wave Propagation

Background:

• Leaky Rayleigh waves are crucial for understanding wave phenomena at liquid-solid interfaces.
• The existence domain and critical velocity of these waves are not fully understood, particularly near the boundary conditions.
• Previous assumptions about critical velocities and wave behavior in specific ranges require reevaluation.

Purpose of the Study:

• To investigate leaky Rayleigh waves at liquid-solid interfaces near their existence domain limits.
• To compute real and complex roots of the secular equation for interface waves at a water/gold-silver alloy boundary.
• To reexamine the controversial existence of leaky Rayleigh waves at a water/ice interface.

Main Methods:

• Numerical computation of real and complex roots of the secular equation.
• Systematic variation of alloy composition to alter critical velocities.
• Analysis of wave behavior in subsonic phase velocity ranges.

Main Results:

• The critical velocity for leaky waves at the water-alloy interface is found to be approximately 1.45% lower than the bulk wave velocity in the liquid.
• Using the real part of complex phase velocity provides only an approximate value for leaky wave velocity.
• Energy leakage is demonstrated in the subsonic phase velocity range, with a physical explanation provided.

Conclusions:

• The critical velocity for leaky waves does not coincide with the bulk wave velocity in the liquid, contrary to popular belief.
• Leaky Rayleigh waves can exist and exhibit energy leakage in subsonic phase velocity ranges.
• Previously identified leaky waves at water/ice interfaces are reclassified as bulk-wave reflection solutions.