摘要:

The singular differential equations for finite temperature relativistic magnetohydrodynamic (MHD) winds integrate to two algebraic equations when the source magnetic field is a monopole. This simplification enables an extensive characterization of the asymptotic wind solutions in terms of source parameters. We will consider only the critical solutions-those that pass smoothly through both an intermediate (Alfvenic) and a fast MHD critical point and expand to zero pressure at infinite radial distance from the source. Because the constants of motion must be specified to extremely high accuracy, the critical solutions cannot be found analytically. Synopsis of many numerical solutions reveals a uniform parametric characterization of the asymptotic wind in terms of one combination of source parameters,Z, the mean source particle energy divided by mc2[sgrave]½, where [sgrave] is a generalization of Michel's (1969) cold relativistic wind strength parameter. Cool winds, withZ<1, behave asymptotically much as Michel's cold wind minimum torque solution;Z1 hot winds have quite different, but simply characterized, asymptotic solutions. Thus, the strength of magnetized relativistic outflows can depend critically upon the temperature of the source.

ISSN:0309-1929    

DOI:10.1080/03091928308221768

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

By using perturbation methods an analytical study has been carried out of large-scale dynamo models, which previously were mainly investigated by numerical methods.

ISSN:0309-1929    

DOI:10.1080/03091928308221769

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

Numerical simulations of internal gravity waves-turbulence are carried out for the inviscid, viscous and forced-dissipative two-dimensional primitive equations using the spectral method. Some of the results are compared with the predictions of the eddy damped quasi-normal Markovian (EDQNM) closure for internal waves of Carnevale and Frederiksen, generalized for periodic boundary conditions and possible random forcing and dissipation. The EDQNM reduces to the Boltzman equation of resonant interaction theory in the continuum space limit and as the forcing and dissipation vanish. However, the limit is singular in the sense that as well as conserving total energy,E, and total cross-correlation between the vorticity and buoyancy fields,C, an additional conservation law, viz.z-momentum,Pz, occurs in the limit. This means that the resonant interaction equilibrium (RIE) solution of the Boltzmann equation differs from the statistical mechanical equilibrium (SME) solution of the EDQNM closure.

ISSN:0309-1929    

DOI:10.1080/03091928308221770

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

The mean motion induced by thermal waves travelling along the surfaces of two parallel planes bounding a layer of homogeneous rotating fluid is studied. Under the Boussinesq and long waves approximations, the fluctuating and the mean velocity components are obtained. The asymptotic expressions and numerical calculations of the zonal and meridional mass flux across vertical planes show that the direction of the net mass flux changes for certain combinations of the frequencies of the moving heat source and the inertial oscillations.

ISSN:0309-1929    

DOI:10.1080/03091928308221771

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor