Showing papers on "Rarefaction published in 1978"
TL;DR: In this paper, general conditions under which rarefaction shocks can exist in the expanding corona of a plasma heated by a laser are derived, for the case of a two-electron temperature isothermal plasma with temperatures Th and Tc.
Abstract: General conditions under which rarefaction shocks can exist in the expanding corona of a plasma heated by a laser are derived. In particular, for the case of a two‐electron temperature isothermal plasma with temperatures Th and Tc, such a shock is shown to occur if Th/Tc≳5+√24. The case of rarefaction shocks induced by the ponderomotive force is also briefly discussed.
156 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 article, the formation and propagation of shock waves in a two-component flowing bubbly mixture has been investigated experimentally and the structure of the shock wave formed by steepening of compression waves is compared with the corresponding features of shocks produced spontaneously in shock tubes.
16 citations
TL;DR: In this article, the disintegration stage of a hot zone in a high energy heavy-ion collision using hydrodynamics is examined, where the initial non-homogeneously compressed matter is assumed to have an oblate shape and an approximate solution to the hydrodynamic equations is obtained by solving two coupled nonlinear differential equations for the semiaxes of the boundary.
16 citations
TL;DR: In this article, the authors investigated the condensation of water vapor via the rarefaction wave in a shock tube by measuring pressure as a function of time and found that at high temperature (260°K), condensation could be adequately explained by the classical nucleation theory combined with a small accommodation coefficient for particle growth.
Abstract: Condensation of water vapor via the rarefaction wave in a shock tube was investigated by measuring pressure as a function of time. At high temperature (260°K), condensation could be adequately explained by the classical nucleation theory combined with a small accommodation coefficient for particle growth. However, at low temperature (230°K), condensation was considerably faster than permitted by classical nucleation, and the classical theory of nucleation is therefore considered to be invalid. Condensation shocks due to the coupling of gasdynamics with condensation kinetics (heat release rate) were also observed.
4 citations
TL;DR: In this paper, a linearized BGK model was used to solve the problem of mass transfer in a capillary, involving evaporation from the inner surface, and the distribution function was chosen of such a form that the boundary conditions could be satisfied as well as the original equation divided into two equations for the functions depending on z and r, respectively.
3 citations
Patent•
18 Nov 1978
TL;DR: In this paper, the authors proposed to enhance exhaust reflux control precison by measures of providing a control valve to move in response to inhaled air negative pressure controlled with rarefaction by atmosphere through a pressure regulating valve.
Abstract: PURPOSE:To enhance exhaust reflux control precison by measures of providing a control valve to move in response to inhaled air negative pressure controlled with rarefaction by atmosphere through a pressure regulating valve to move in comparatively response to Venturi negative pressure and exhaust reflux passage negative pressure.
2 citations
16 Jan 1978
TL;DR: In this paper, a simplified parametric model of the flowfield produced by impingement of a high-energy laser pulse onto a nonablative surface in a static environment is described.
Abstract: A simplified parametric model of the flowfield produced by impingement of a high-energy laser pulse onto a nonablative surface in a static environment is described. An attempt has been made to account for the twodimensional effects arising out of the rarefaction structure within the laser-heated gases. An optimization model is developed to indicate the laser spot size, pulse width, and intensity dependencies of the efficiency of delivery of both impulse and mechanical energy to the target surface.
1 citations
Patent•
15 Mar 1978
TL;DR: In this article, the rarefaction of the mixed gas is prevented by reducing the volume of the flow dividing chamber in acceleration, and the thickening of the mix is prevented in deceleration.
Abstract: PURPOSE:In the flow divider which distributes fuel to each injection valve, the rarefaction of the mixed gas is prevented by reducing the volume of the flow dividing chamber in acceleration, and the thickening of the mixed gas is prevented by increasing the volume of the flow dividing chamber in deceleration.
1 citations
TL;DR: In this paper, the propagation of ion acoustic waves in a two temperature plasma is discussed theoretically, and a rarefaction solution is presented, showing that above a critical value of cold electron density, electron non-linearity overtakes the ion nonlinearity.
Abstract: The propagation of ion acoustic waves in a two temperature plasma is discussed theoretically. The cold electrons in this system behave like ions with reduced mass. Owing to their high velocity, these electrons can produce significant amounts of convective nonlinearity, out of phase with the ion nonlinearity. Above a critical value of cold electron density, electron nonlinearity overtakes the ion nonlinearity. A rarefaction solution is presented.
1 citations
01 Sep 1978
TL;DR: In this article, an investigation is made of the flow of an electrically conducting rarefied gas due to the time-varying motion of an infinite porous plate, the gas being permeated by a transverse magnetic field.
Abstract: An investigation is made of the flow of an electrically conducting rarefied gas due to the time-varying motion of an infinite porous plate, the gas being permeated by a transverse magnetic field. The suction is taken to be a constant and the magnetic lines of force are taken to be fixed relative to the fluid. The effects of magnetic field, rarefaction parameter, suction parameter are shown by means of some tables. The expressions of the skin friction for the two particular cases have also been obtained.