Molecular hydrodynamics: Vortex formation and sound wave propagation

Molecular simulations of sound wave propagation in simple gases

Molecular simulations of sound waves propagating in a dilute hard sphere gas have been performed using the direct simulation Monte Carlo method. A wide range of frequencies is investigated, including very high frequencies for which the period is much shorter than the mean collision time. The simulation results are compared to experimental data and approximate solutions of the Boltzmann equation...

Sound Wave in Vortex with Sink

Using Komar’s definition, we give expressions for the mass and angular momentum of a rotating acoustic black hole. We show that the mass and angular momentum so defined, obey the equilibrium version of the first law of Black Hole thermodynamics. We also show that when a phonon passes by a vortex with a sink, its trajectory is bent. The angle of bending of the sound wave to leading order is quad...

Downward Wave Propagation on the Polar Vortex

This paper considers the propagation of waves on the edge of a stratospheric polar vortex, represented by a three-dimensional patch of uniform potential vorticity in a compressible quasigeostrophic system. Waves are initialized by perturbing the vortex from axisymmetry in the center of the vortex, and their subsequent upward and downward propagation is measured in terms of a nonlinear, pseudomo...

Discrete Simulation of Sound Wave Propagation

Sound Wave Propagation in Viscous Liquid-Filled Non-Rigid Carbon Nanotube with Finite Length

   In this paper, numerical results obtained and explained from an exact formula in relation to sound pressure load due to the presence of liquid inside the finite-length non-rigid carbon nanotubes (CNTs), which is coupled with the dynamic equations of motion for the CNT. To demonstrate the accuracy of this work, the obtained formula has been compared to what has been used by other research...