摘要:

An efficient scheme has been developed for the numerical solution of the Navier-Stokes and energy equations applied to the flow of an incompressible fluid in a two-dimensional channel. A vorticity-stream function formulation with a generalized curvilinear coordinate system is used for a wide range of geometric configurations. The system of coupled nonlinear equations is solved by a block relaxation scheme for which the rate of convergence is substantially increased by a multigrid technique. Two numerical experiments are described to illustrate the efficiency of the proposed approach.

ISSN:0149-5720    

DOI:10.1080/01495728408961831

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

A numerical algorithm that is second-order accurate in time has been developed for the conjugated problem of a separated, compressible flow field and a conductive solid body. The full two-dimensional time-dependent Navier-Stokes equations are coupled with the time-dependent energy equation for the solid body and are solved simultaneously. using implicit algorithms. The energy equation for the solid body may include arbitrarily distributed heat sources. The algorithm has been examined for the case of two-dimensional supersonic compression-corner interaction, with a heat source embedded in the wall in the vicinity of the separation bubble and the attached boundary layer. The effect of the heat source on the flow field is studied for steady and transient cases.

ISSN:0149-5720    

DOI:10.1080/01495728408961832

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

Three primitive-variable formulations used on nonstaggered grids have been developed and examined. For comparison and assessment, an internally heated rectangular-elbow flow problem whose exact solution exists and is known is introduced. The characteristics of the three formulations depend on how the continuity constraint is incorporated. If the continuity equation is directly used, the resulting matrix is solved by a direct matrix solver. If the pressure Poisson equation is used or if the nodal velocities in the continuity are substituted for nodal pressures, an iterative scheme such as the Gauss-Seidel method can be used. These formulations must be modified slightly when inhomogeneous Neumann boundary conditions are imposed. On the basis of the computed solution, it is recommended that the formulation using the pressure substitution be used in conjunction with second-order accurate discretized momentum equation applied to the boundary.

ISSN:0149-5720    

DOI:10.1080/01495728408961833

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

As a preliminary study of the nature of heat transfer between a packed bed and a bounding wall, a first-order model is considered where the bed is taken to be a row of rectangular compacts. Results are obtained numerically for the fluid flow and heat transfer in the voids between compacts and to the wall. Different gap sizes and compact-plane separations, with Prandtl numbers of 0.72 and 7 and Reynolds numbers ranging from 0 to 100, are considered. As the compact separation and the Reynolds number increase, the heat transfer from the void increases and the maximum temperature decreases. Increasing the Prandtl number improves the heat transfer from the void, and when the compact-bounding plane separation increases, the fluid flow and heat transfer settle down to essentially a stationary value, independent of the Reynolds number.

ISSN:0149-5720    

DOI:10.1080/01495728408961834

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

Numerical results have been obtained for the effects of wall conduction and radiation heat exchange between surfaces on laminar natural-convection heat transfer in a two-dimensional rectangular cavity. Parametric heat transfer calculations have been performed and results are presented In graphic and tabular form. Local and average Nusselt numbers along the cavity walls are reported for a range of parameters of physical interest. The findings suggest that the local or the average Nusselt number may not be a meaningful parameter for use in conjugate heat transfer problems. The results indicate that natural-convection heat transfer in the cavity is reduced by heat conduction in the walls and radiation exchange among surfaces.

ISSN:0149-5720    

DOI:10.1080/01495728408961835

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

An efficient alternating-direction finite-element method is applied to the solution of nonlinear heat transfer problems. The technique is comparable in accuracy to standard finite-element methods while offering a substantial reduction in computer costs in terms of both processing time and core storage. The alternating-direction formulation is presented together with a discussion of the resulting matrix system and treatment of the boundary conditions. A heat conduction problem involving phase change is solved as a demonstration of the efficiency of the algorithm. The latent heat effect is accounted for by rapid variations in the heat capacity term.

ISSN:0149-5720    

DOI:10.1080/01495728408961836

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

10. Free convection about a vertical cylinder in a porous medium subject to constant wall temperature or constant wall heat flux is considered. The influence of uniform lateral mass flux on the boundary-layer transport is studied. Numerical results for heat transfer along the boundary and temperature profiles are presented for various values of the parameter cj which is a measure of the effect of injection or withdrawal of fluid as compared to the combined transverse curvature and lateral mass flux effects.

ISSN:0149-5720    

DOI:10.1080/01495728408961837

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

ISSN:0149-5720    

DOI:10.1080/01495728408961838

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor