心臓病診療プラクティス 16. 心不全を癒す

Preface. 1. Plasmas and Dust. 2. Charging Mechanisms and Experiments. 3. Space Observations. 4. Multispecies Formalism and Waves. 5. Electrostatic Modes. 6. Electromagnetic Modes. 7. Fluctuating Dust Charges. 8. Self-Gravitation. 9. Mass and Size Distributions. 10. Other Modes. 11. Conclusions and Outlook. Bibliography. Index.

https://physicstoday.scitation.org/doi/pdf/10.1063/1.1404853

Waves in Dusty Space Plasmas

Hydrodynamic and hydromagnetic stability

The influence of heat and mass transfer on MHD peristaltic flow through a porous space with compliant walls

Effect of the induced magnetic field on peristaltic flow of a couple stress fluid

We investigate the problem of the unsteady mixed convection peristaltic mechanism. The flow includes a temperature-dependent viscosity with thermal diffusion and diffusion-thermo effects. The peristaltic flow is between two vertical walls, one of which is deformed in the shape of traveling transversal waves exactly like peristaltic pumping and the other of which is a parallel flat plate wall. The equations of momentum, energy, and concentration are subject to a set of appropriate boundary conditions by assuming that the solution consists of two parts: a mean part and a perturbed part. The solution of the perturbed part has been obtained by using the long-wave approximation. The mean part has been solved and coincides with the approximation of Ostrach. The mean part (zeroth order), the first order, and the total solution of the problem have been evaluated numerically for several sets of values of the parameters entering the problem. The skin friction, and the rate of heat and mass transfer at the walls are obtained and illustrated graphically.

Mixed convective heat and mass transfer in a non-Newtonian fluid at a peristaltic surface with temperature-dependent viscosity

We have analyzed an incompressible flow of electrically conducting biviscosity fluid through an axisymmetric non-uniform tube with a sinusoidal wave under the considerations of long wavelength and low Reynolds number. In our analysis we are taking into account the induced magnetic field. The analytic solution has been obtained from which the axial velocity, the axial induced magnetic field and the axial pressure gradient have been derived. The results for the pressure rise Δ P λ ( t ) , frictional force per wavelength F λ ( t ) and the axial induced magnetic field h z have been computed numerically and the results were studied for various values of the physical parameters of interest, such as the magnetic Prandtl number p m , the magnetic field parameter M , the Reynolds number Re , the upper limit apparent viscosity coefficient β , and the time averaged mean flow rate θ .

Peristaltically induced transport of a MHD biviscosity fluid in a non-uniform tube

The instability of a thin sheet of dielectric liquid moving in the same direction as an air stream in the presence of a uniform horizontal electric field is studied theoretically. It is found that aerodynamic-enhanced instability occurs if the Weber number is much less than a critical value related to the ratio of the air and liquid stream velocities, the electric field, and the dielectric constant values. The electric field is found to have a stabilizing effect, and there exists a critical Weber number above which instability is suppressed by the surface tension effect. The condition for disintegrating the sheet is obtained in terms of the electric field values, and some limiting cases are recovered.

Electro-aerodynamic instability of a thin dielectric liquid sheet sprayed with an air stream.

The electrohydrodynamic instability of the plane interface between two uniform, superposed viscous streaming dielectric fluids through porous media is considered in the presence of a horizontal electric field. In the absence of surface tension, perturbations transverse to the direction of streaming are found to be unaffected by either the presence of streaming or an electric field as long as perturbations in the direction of streaming are ignored. Whereas for perturbations in all other directions there exists instability for a certain wave-number range. The instability of this system can be delayed by the presence of a tangential electric field. Both the electric field and surface tension are able to suppress Kelvin-Helmholtz instability for small wavelength perturbations and the medium porosity reduces the stability range given in terms of a difference between the streaming velocities and the electric-field effect. For the case in which the heavier fluid overlies the lighter one, it is found that both surface tension and the tangential electric field succeed in stabilizing a certain wave-number range that was unstable in their absence. R´ esum´ e :N ousetudions l'instabilite electrohydrodynamique de l'interface planaire entre deux films dielectriques uniformes et superposes se deplacant a travers un milieu poreux. En l'absence de tension de surface, les perturbations transverses a la direction de circulation du fluide sont insensibles au deplacement ou a la presence d'un champ electrique si nous ignorons les perturbations dans la direction du deplacement. Par contre, avec des perturbations dans toutes les autres directions, il y a possibilite d'instabilite dans un certain domaine du vecteur d'onde. L'instabilite du systeme est reduite par la presence d'un champ electrique tangentiel. Le champ electrique et la tension de surface sont tous deux capables de supprimer l'instabilite de Kelvin-Helmholtz pour des perturbations de petit vecteur d'onde. La porosite du milieu reduit le domaine de stabilite decrit en terme d'une difference entre la vitesse de deplacement et l'effet du champ electrique. Dans le cas ou le fluide lourd est au dessus du fluide leger, la tension de surface et le champ electrique tangentiel reussissent a stabiliser un certain domaine du vecteur d'onde qui etait instable en leur absence. (Traduit par la r ´

Mohamed F. El-Sayed

Papers

Mixed convective heat and mass transfer in a non-Newtonian fluid at a peristaltic surface with temperature-dependent viscosity

Peristaltically induced transport of a MHD biviscosity fluid in a non-uniform tube

Electro-aerodynamic instability of a thin dielectric liquid sheet sprayed with an air stream.

Electrohydrodynamic instability of two superposed viscous streaming fluids through porous media

Electrohydrodynamic Stability of Two Superposed Viscous Fluids