摘要:

Flow details inside the buoyant boundary layer in the heat-up process of a contained, stably stratified, fluid are presented. Numerical solutions were obtained for the heatup problem in a cylinder considered by Sakurai and Matsuda (1972). By plotting the scaled vertical velocityWversus the scaled temperature as functions of the normal distance from the sidewall, the precise shape of the buoyant layer spiral is constructed. The analogy between this spiral and the Ekman spiral in rotating fluids is apparent. As the Rayleigh numberRaincreases, the magnitude of the scaled vertical velocity increases substantially, but the scaled temperature does not vary appreciably. The buoyant layer thickness is determined by measuring the zero-crossing normal distance for the vertical velocity. The buoyant layer suction increases significantly asRaincreases. The effects of vertical level and of time on the qualitative behavior of buoyant layer flows are found to be small. The buoyant layer flows decay over the heat-up time scaletn;thcharacterizes the time span over which the overall adjustment process in the inviscid interior region is accomplished. This work clarifies that the analogy between heat-up and spin-up, which has been known to exist in the main body of inviscid fluid, applies equally well to the boundary layer regions.

ISSN:0309-1929    

DOI:10.1080/03091928408222845

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

We reconsider the problem of formulation of a model for polythermal glaciers, focussing attention in particular on the temperate zone where ice and water can coexist at the melting temperature. The energy equation for the ice-water mixture in this zone introduces amoisture flux, and a constitutive law for this flux is required. By analogy with the flow through a porous medium, we use Darcy's law (i.e. the second momentum equation of a two-phase flow model with “porous” geometry), and then require a mechanical constitutive relation relating the water pressurepwto the average ice pressurepi. Experience in two phase flows suggests thatpw=pimay be problematical, and experience in soil mechanics suggests it is inaccurate. A constitutive relation is therefore presented based on work of Nye (1976), and its effect on the well-posedness of the model is examined. Considerations of the sort presented here have clear relevance in the formulation of similar problems in other geophysical situations, notably mantle convection.

ISSN:0309-1929    

DOI:10.1080/03091928408222846

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

The equilibrium properties of the magnetic field of an axisymmetric star are studied. A family of analytical solutions to the magnetohydrostatic equations is found, which are used to model the slow evolution of the field through a series of equilibria.

ISSN:0309-1929    

DOI:10.1080/03091928408222847

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

In this unsteady barotropic model of the circulation over an oceanic continental shelf and shelf break, account is taken of variations in the surface wind stress along the coast. It is found that the position of maximum onshore flow is very sensitive to the alongshore variation of the wind stress, and that the longshore current becomes more influenced by the shelf break as the wind stress decreases.

ISSN:0309-1929    

DOI:10.1080/03091928408222848

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor