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Square Cavity (square + cavity)

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Selected Abstracts

Internal gravity wave resonance of thermal convection fields in rectangular cavities with heat-flux vibration (effects of aspect ratio on the fields)

HEAT TRANSFER - ASIAN RESEARCH (FORMERLY HEAT TRANSFER-JAPANESE RESEARCH), Issue 3 2007
Shota Matsumura
Abstract In this paper the thermal convection field and its resonance phenomena in a rectangular cavity with heat-flux vibration are numerically examined and the results are compared with those of a square cavity. As in the case of ,=1, the critical angular velocity at which the relative amplitude of the midplane Nusselt number ,m has a local maximum agrees very well with the resonance angular velocity of the internal gravity wave ,r, estimated by the theoretical equation proposed by Thorpe, even when the aspect ratio is ,=5 and the Prandtl number is Pr=0.71 for a range of the Rayleigh number Ra. However, ,m has two local maxima for a larger Ra, which is peculiar to the case of larger ,. The time variation of sub-components of the fluctuating component of the midplane Nusselt number shows that the phase at the maximum value of ,m agrees well with that of the sub-component of velocity for the first resonance angular velocity ,r. For the other angular velocity ,r2, the phase of ,m agrees with that of the sub-component of temperature. Moreover, we found that the boundary angular velocity ,0 between the first two of the five , regions, which classify the thermal convection fields against ,, can be expressed by a function of ,, Ra, and Pr and that ,m is independent of , and Ra for a relatively wide range of ,/,0. © 2007 Wiley Periodicals, Inc. Heat Trans Asian Res, 36(3): 158, 171, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.20149 [source]

Global flow instability in a lid-driven cavity

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS, Issue 8 2010
V. B. L. Boppana
Abstract The stability of flow in a lid-driven cavity is investigated using an accurate numerical technique based on a hybrid scheme with spectral collocation and high-order finite differences. A global stability analysis is carried out and critical parameters are identified for various aspect ratios. It is found that while there is reasonable agreement with the literature for the critical parameters leading to loss of stability for the square cavity, there are significant discrepancies for cavities of aspect ratios 1.5 and 2. Simulations of the linearized unsteady equations confirm the results from the global stability analysis for aspect ratios A = 1, 1.5 and A = 2. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Solving high Reynolds-number viscous flows by the general BEM and domain decomposition method

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS, Issue 3 2005
Yongyan Wu
Abstract In this paper, the domain decomposition method (DDM) and the general boundary element method (GBEM) are applied to solve the laminar viscous flow in a driven square cavity, governed by the exact Navier,Stokes equations. The convergent numerical results at high Reynolds number Re = 7500 are obtained. We find that the DDM can considerably improve the efficiency of the GBEM, and that the combination of the domain decomposition techniques and the parallel computation can further greatly improve the efficiency of the GBEM. This verifies the great potential of the GBEM for strongly non-linear problems in science and engineering. Copyright © 2004 John Wiley & Sons, Ltd. [source]

A coupled lattice BGK model for the Boussinesq equations,

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS, Issue 4 2002
Zhaoli Guo
Abstract In this paper, a thermal lattice BGK model is developed for the Boussinesq incompressible fluids. The basic idea is to solve the velocity field and the temperature field using two independent lattice BGK equations, respectively, and then combine them into one coupled model for the whole system. The porous plate problem and the two-dimensional natural convection flow in a square cavity with Pr=0.71 and various of Rayleigh numbers are simulated using the model. The numerical results are found to be in good agreement with the analytical solutions or those of previous studies. Copyright © 2002 John Wiley & Sons, Ltd. [source]