Topic
Hydrodynamic theory
About: Hydrodynamic theory is a research topic. Over the lifetime, 633 publications have been published within this topic receiving 16226 citations.
Papers published on a yearly basis
1 / 2
Papers
TL;DR: In this paper, a unified hydrodynamic theory is presented that is appropriate for crystals; smectic, cholesteric, and nematic liquid crystals; glasses; and normal fluids.
Abstract: A unified hydrodynamic theory is presented that is appropriate for crystals; smectic, cholesteric, and nematic liquid crystals; glasses; and normal fluids. In the theory, the increased spatial degeneracy as the system progresses from crystalline and mesomorphic phases to the isotropic fluid phase is marked by successive reductions in the number of firstorder elastic constants and in the number of transport coefficients. Distinction between local lattice dilations and local mass changes, and recognition of processes like vacancy diffusion that this difference makes possible, are crucial for understanding the connection between theories in different phases. Formulas are derived that give the number of hydrodynamic modes and the frequencies, lifetimes, and intensities of these modes in all of the above systems. In the nematic and cholesteric phases, the results agree with some found previously. In more complex systems, they are new. An attempt is made to explain the differences between the present hydrodynamic theory and other phenomenological proposals.
898 citations
TL;DR: In this article, the velocity correlation function of an atom in a simple liquid is calculated using a frequency-dependent version of the Stokes-Einstein formula, and good agreement is obtained with the velocities determined by Rahman using computer experiments.
Abstract: The velocity correlation function of an atom in a simple liquid is calculated using a frequency-dependent version of the Stokes-Einstein formula. Stokes's law for the frictional force on a moving sphere is generalized to arbitrary frequency, compressibility, and visco-elasticity, with arbitrary slip of the fluid on the surface of the sphere. This frequency-dependent friction coefficient is then used in a generalized Stokes-Einstein formula, and the velocity correlation function is found by Fourier inversion. By using physically reasonable values for viscoelastic parameters, good agreement is obtained with the velocity correlation function determined by Rahman using computer experiments.
617 citations
TL;DR: In this article, a hydrodynamic theory of spin waves is developed for certain magnetic systems in analogy with the derivation of two-fluid hydrodynamics for liquid helium.
Abstract: A hydrodynamic theory of spin waves is developed for certain magnetic systems in analogy with the derivation of two-fluid hydrodynamics for liquid helium. The systems considered are "isotropic" and "planar" ferromagnets and antiferromagnets. In each system, low-frequency spin waves are predicted to exist at long wavelengths for any temperature below the transition to the paramagnetic phase. The real part of the frequency is given exactly in terms of thermodynamic quantities. The damping rate is proportional to the square of the real part of the frequency in each case, and hence is negligible in the long-wavelength limit, compared to the real part. These results for the damping rates are new, and disagree with previous microscopic calculations for the Heisenberg ferromagnet and antiferromagnet. An experiment using neutron diffraction is proposed to test the hydrodynamic theory in the almost isotropic antiferromagnet RbMn${\mathrm{F}}_{3}$. The assumptions necessary to derive the hydrodynamic theory are discussed in detail, as are the limits of validity of the theory, and the applicability of the results to real systems.
551 citations
TL;DR: A modified hydrodynamic theory which takes some account of strength effects is used to predict the deceleration of a long rod after striking a target as discussed by the authors, and the results are then compared with experimental data from X-ray observations.
Abstract: A modified hydrodynamic theory which takes some account of strength effects is used to predict the deceleration of a long rod after striking a target. The results are then compared with experimental data from X-ray observations.
489 citations
TL;DR: In this paper, the second-harmonic generation of light at metal surfaces within the hydrodynamic theory of the electron gas is discussed, and expressions for the phenomenological parameters $a$ and $b$ of Rudnick and Stern are presented.
Abstract: We discuss the second-harmonic generation of light at metal surfaces within the hydrodynamic theory of the electron gas; expressions for the phenomenological parameters $a$ and $b$ of Rudnick and Stern are presented, and the possibility of a resonance in $a$ at optical or near-uv frequencies is discussed. A recent plasmon-enhanced experiment of Simon et al. is analyzed, and the use of such experiments to determine $a$ and $b$ is considered; new experiments are proposed to aid in such a determination.
384 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2021 | 25 |
| 2020 | 14 |
| 2019 | 12 |
| 2018 | 17 |
| 2017 | 19 |
| 2016 | 18 |