摘要:

A least-squares finite element method (LSFEM) has been developed to investigate the phenomenon of natural convection caused by temperature and concentration buoyancy effects in rectangular enclosures with different geometric aspect ratios. The time dependent Navier-Stokes equations, the energy and the mass balance equations for an incompressible, constant property fluid in the Boussinesq approximation are reduced into a first-order velocity-pressure-vorticity-temperature-heat flux-concentration-mass flux (u-p-ω-T-q-C-J) formulation. The coupled system is discrelized by backward differencing in time. For the case of heat and mass transfer from side walls, results for both augmenting and opposing flows are obtained with Prandtl numberPr = 0.7, Schmidt numberSc = 0.6 and 0.7 (Le = 1), Grashof numberGrup to 106, buoyancy ratio χ = − 0.2 to − 5.0 and geometric aspect ratio of 1. For the case of heating from below, we test the LSFEM with two Rayleigh-Bénard convection problems. Then the LSFEM algorithm is used to solve the doubly-diffusive convection in a horizontal rectangular cavity heated from below with Grashof number 5.5 x 105and geometric aspect ratio 7.

ISSN:1061-8562    

DOI:10.1080/10618569408904497

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

A finite element method for the analysis of two-layer tidal current flow considering an open boundary condition is presented in this paper. The nonlinear shallow water equation are used for both upper and lower layers as the governing equation. The incident wave condition, which does not cause spurious reflective waves on the open boundary, has been applied lo the boundary condition in the two layer tidal current analysis. In this method, both velocity and water elevation are assumed to be a linear combination of the incident component as a known function, and the reflective component, which is essentially unknown. A subdomain located adjacent to the open boundary is introduced to determine the reflective wave component. The reflective wave component on the open boundary can be extracted by computation in the subdomain. The numerical results were compared with the analytical solutions and observed data and show good agreement.

ISSN:1061-8562    

DOI:10.1080/10618569408904498

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

Analysis/design calculations of transonic flow are discussed and several improvements are made. The nonisentropic potential method is used to calculate the inviscid transonic flow analysis problem instead of the traditional potential method. An inverse integral 3D boundary layer method is used to calculate the boundary layer in the viscous transonic flow analysis problem. The viscous/inviscid interaction calculations are carried out by a semi-inverse coupling scheme. In design problem calculations, an improved residual-correction method is used. Three individual methods are combined in a global algorithm and computing code. The improvements speed up the convergence, increase applicability and computational efficiency. Some numerical results are given to illustrate that the present method provides an effective engineering tool of high accuracy and efficiency in three dimensional transonic analysis and design situations.

ISSN:1061-8562    

DOI:10.1080/10618569408904499

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

A well-known problem in fluid dynamics is the prediction of storm surges. In the present work, a coastal zone numerical model is described using finite difference techniques. The model has been applied to the prediction of storm surges generated by a tropical cyclone along the coasts of Sri Lanka and southern Indian peninsula. Experiments are carried out to simulate the surges associated with a forcing wind-stress distribution representative of the 1964 Rameswaram cyclone and the 1992 Tuticorin cyclone. The simulated surges for both cyclones are in good agreement with the reported counterpart maximum surge values.

ISSN:1061-8562    

DOI:10.1080/10618569408904500

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor