Nonlinear ultrasonic waves in water‐air mixtures

Nonlinear Ultrasonic Waves for Structural Health Monitoring

Nonlinear ultrasonic waves in solids have shown good sensitivity to quasi-static stresses. The stress sensitivity of elastic waves is typically associated to finite strains (e.g. theory of acoustoelasticity). In the case of waveguides, classical nonlinear theories for guided waves are still based on the assumption of finite strains. In the case of constrained solids subjected to thermal excursi...

Sound Speed in LiquidGas Mixtures: WaterAir and WaterSteam

The sound speed of a two-phase fluid, such as a magma-gas, water-air, or water-steam mixture, is dramatically different from the sound speed of either pure component. In numerous geologic situations the sound speed of such two-phase systems may be of interest: in the search for magma reservoirs, in seismic exploration of geothermal areas, in prediction of P wave velocity decreases prior to eart...

Nonlinear Ultrasonic Guided Waves for Microstructure Characterization of Hollow Cylinders

The issue of non-destructive characterization of material microstructure with respect to precursors to macroscale damage initiation is addressed. Ultrasonic guided waves are known to be sensitive to material nonlinearity, which is evident through the generation of higher harmonic modes. Thus, nonlinear guided waves have strong potential to identify precursors to macroscale damage and revolution...

On Nonlinear Water Waves in a Channel

Analysis of Ultrasonic Velocities in Hydrocarbon Mixtures

Ultrasonic velocity data on hydrocarbon mixtures was shown by Wang and Nur [JASA 89, 2725 (1991)] to agree quite well with the predictions of a simple mixing rule (volume average of velocity). The same data is reanalyzed using Wood's formula and the time average approximation. Wood's formula for acoustic velocity is shown to be always less than the time average formula, which is itself always l...