Topic
Rarefaction
About: Rarefaction is a research topic. Over the lifetime, 1852 publications have been published within this topic receiving 26943 citations.
Papers published on a yearly basis
Papers
More filters
TL;DR: In this article, the time-dependent continuity and momentum equations for H(+) are solved in order to study the temporal evolution of density perturbations in the supersonic, collisionless polar wind.
Abstract: The time-dependent continuity and momentum equations for H(+) are solved in order to study the temporal evolution of density perturbations in the supersonic, collisionless polar wind. The results indicate that the sophisticated computer models of small-scale plasma expansions are indeed applicable to large-scale flow problems. The important prediction of the production of superthermal ions from small-scale simulations by the process of plasma expansion is borne out by the calculations in this paper. Energetic ions are produced for each type of density perturbation through the plasma expansion process. In the case of an extended density depletion, the forward-reverse shock pair forms when the depletion is very strong, but otherwise only the forward shock forms. In the case of localized density depletions, the density cavity evolves into two rarefaction waves joined by a forward-reverse shock pair. In the case of localized density enhancements, the shock pair evolves from compressive waves.
52 citations
TL;DR: It is shown that the Coulomb-like friction term make waves (including rarefaction, shock and delta shock) bend into parabolic shapes for the Riemann solutions.
52 citations
TL;DR: In this article, the authors conjecture that the structure of nova shells is a consequence of the Rayleigh-Taylor instability of supernovae, in which rings are formed by the smearing action of high rotational velocities.
Abstract: After a shock wave has accelerated the outer layers of a star during a stellar explosion, a rarefaction wave moves back into the stellar material, resulting in the conversion of internal energy into kinetic energy This additional acceleration can be Rayleigh-Taylor unstable Two-dimensional hydrodynamic calculations are presented for the case of Type II supernovae, showing that the instability results in the ejection of a clumpy shell It is unlikely that radiation transport can dump the instability for normal Type II supernove We further conjecture that the structure of nova shells is a consequence of t We fur ther conjecture that the structure of nova shells is a consequence of this instability; in this case, rings are formed by the smearing action of high rotational velocities
51 citations
TL;DR: In this paper, the friction factor for incompressible rarefied gas flow through microchannels is analyzed and a theoretical investigation is conducted in order to underline the conditions for experimentally evidencing rarefaction effects on the pressure drop.
Abstract: This paper is devoted to analysing the friction factor for incompressible rarefied gas flow through microchannels. A theoretical investigation is conducted in order to underline the conditions for experimentally evidencing rarefaction effects on the pressure drop. It is demonstrated that for a fixed geometry of the microchannel cross-section, it is possible to calculate the minimum value of the Knudsen number for which the rarefaction effects can be observed experimentally, taking into account the uncertainties related to evaluation of the friction factor.
51 citations
TL;DR: In this paper, an extension of the Graetz problem to include the rarefaction effect, viscous dissipation term and axial conduction with constant-wall-heat-flux thermal boundary condition is presented.
51 citations