摘要:

A system in which electrons are projected radially inwards from a spherical surface, has been proposed for the confinement of a plasma at thermonuclear temperatures. The equilibrium, economics, and stability of such a system are discussed theoretically.Although we conclude that it is of doubtful utility as a thermonuclear reactor, it may be possible to produce in this way small regions of thermonuclear plasma for study. The device appears to be unstable at economic densities. The stability is discussed in terms of a virial, which turns out to be mathematically tractable in this geometry.

ISSN:0031-9171    

DOI:10.1063/1.1705917

出版商:AIP    

年代:1959

数据来源: AIP

摘要:

The technique developed in the general theory of discontinuities is applied to the basic equations of unsteady magnetohydrodynamics in order to find the conditions to be satisfied by the discontinuities in the derivatives of the significant flow and magnetic field parameters. In the formulation of the basic equations use is made of the ``magnetohydrodynamic approximation.'' This amounts to the assumption that the magnetic energy is very large compared with the electric energy, or physically, that the displacement current is negligible. The fluid itself is considered to be infinitely conductive, inviscid, and compressible. With the aid of the relations satisfied by the jumps in the derivatives of the parameters the various characteristic manifolds are found. Finally, it is shown that these manifolds are hypersurfaces along which small disturbances and weak shocks are propagated.

ISSN:0031-9171    

DOI:10.1063/1.1705918

出版商:AIP    

年代:1959

数据来源: AIP

摘要:

The second virial coefficient is calculated by a new method which exploits certain results known from formal scattering theory. In particular it is shown that the essential quantity may be expressed as the determinant of theSmatrix at a given energy. The present approach suggests several approximation techniques and also seems applicable to many‐body problems.

ISSN:0031-9171    

DOI:10.1063/1.1705919

出版商:AIP    

年代:1959

数据来源: AIP

摘要:

A tensorial ordering parameter, obeying a linear relaxation equation, is introduced to describe the elastic shearing strain exhibited by a liquid at high frequencies. The coefficients in the relaxation‐rate equation and the shear modulus in the stress tensor are linked by the Onsager‐Casimir reciprocal relations with the result that the total rate of deformation is divided into elastic and viscous parts, in agreement with a hypothesis made by Frenkel to derive the viscoelastic stress relaxation equation of Maxwell. The hypersound wave velocity is computed from the thermal conductivity by an adaptation of a theory of Debye and from it the shear modulus and shear relaxation time are computed, effects of thermal relaxation being taken into account. In three nonassociated liquids, order‐of‐magnitude agreement is found with values calculated from a theory by Mooney.

ISSN:0031-9171    

DOI:10.1063/1.1705920

出版商:AIP    

年代:1959

数据来源: AIP

摘要:

An investigation has been made of the stationary supersonic nozzle flow of a reacting gas mixture of nitrogen tetroxide and dioxide carried at low concentration in nitrogen. A judicious choice of supply conditions and nozzle geometry made it possible to produce flows either in chemical equilibrium or in states between this and the frozen flow. The flow could be fully determined from pressure and area measurements and, by applying an equation for the reaction mechanism, rate constants of recombination could be found. The results of these measurements agreed with those obtained from independent optical absorption measurements, and the third‐order rate constant for recombination was found to be 3 × 1014cm6mole−2sec−1for 210 <T< 330°K. Finally, experiments with stationary oblique shocks led to a determination of the dissociation rate constant.

ISSN:0031-9171    

DOI:10.1063/1.1705921

出版商:AIP    

年代:1959

数据来源: AIP

摘要:

In a high‐temperature gas, the speed of sound depends upon the chemical composition, sound frequency, and chemical reaction rates. Two limiting sound speeds are normally distinguished: that of ``frozen'' or constant chemical composition, and the ``equilibrium'' sound speed. Equations to determine these two sound speeds are presented for a nitrogen‐oxygen system and numerical data are presented for conditions behind a normal shock in air to a speed of Mach 20.

ISSN:0031-9171    

DOI:10.1063/1.1705922

出版商:AIP    

年代:1959

数据来源: AIP

摘要:

Observations indicate that the amplitudes of distant seismic signals from underground nuclear explosions are approximately proportional to the total energy release. It is shown that these observations can be accounted for by a simple model which assumes that the nonlinear region close to the explosion is similar for all explosions and that the linear region transmits only low‐frequency waves.

ISSN:0031-9171    

DOI:10.1063/1.1705923

出版商:AIP    

年代:1959

数据来源: AIP

摘要:

The measured velocity of gaseous detonation waves is less than that predicted by the Chapman‐Jouguet plane wave theory. The velocity deficit (difference between theoretical and measured velocities) has been found earlier to vary inversely with the tube diameter and initial pressure. A quantitative explanation of this effect is advanced by determining the growth of the viscous boundary layer on the tube wall and its effect upon the flow in the reaction zone of the detonation front. It is proposed that the boundary layer displacement effect within the reaction zone produces a uniform flow divergence throughout the detonation front. The velocity deficit due to this two‐dimensional flow is determined, using measured values of reaction zone thickness. The agreement of the velocity deficit with measured values is within a factor of two for the five hydrogen‐oxygen‐inert gas mixtures and one acetylene‐oxygen mixture for which sufficient data are available.

ISSN:0031-9171    

DOI:10.1063/1.1705924

出版商:AIP    

年代:1959

数据来源: AIP

摘要:

Hot‐wire measurements of the fluctuations in turbulent, constant‐pressure boundary layers have been made at Mach numbers of 1.72, 3.56, and 4.76 and a Reynolds number based on momentum thickness of about 30 000. The distribution of the static‐temperature fluctuation levels through the boundary layer is approximately similar at the various Mach numbers, and the levels are proportional to the mean static‐temperature difference across the boundary layer. A decrease of the velocity fluctuation levels is observed as the Mach number is increased. There is a high negative correlation between the velocity and temperature fluctuations at all Mach numbers.

ISSN:0031-9171    

DOI:10.1063/1.1705925

出版商:AIP    

年代:1959

数据来源: AIP

摘要:

The disturbed motion of a liquid having a free surface in a vertical, rotating, circular cylinder and an equilibrium distribution of velocity corresponding to rigid body rotation is studied in linear approximation. It is shown that a vertical gradient of velocity necessarily generates vorticity, whence the disturbed motion cannot remain irrotational. (Earlier studies of this problem were based on shallow water theory, in which approximation the disturbed motion can remain irrotational.) The natural frequencies for the free surface oscillations are studied in some detail for a deep tank (say depth > diameter), and it is found that one effect of rotation is to split the pairs of frequencies (that would have been of equal magnitude and opposite sign) for the nonrotating liquid. In addition, new resonant frequencies are found that have no counterpart for a nonrotating liquid and for which the motion does not fall off exponentially with depth. The results are applied to forced, transverse oscillations of the tank, and explicit solutions are given for three special cases.

ISSN:0031-9171    

DOI:10.1063/1.1705926

出版商:AIP    

年代:1959

数据来源: AIP