Mixed finite element formulation of algorithms for double-diffusive convection in a fluid-saturated porous medium

The onset of double diffusive convection in a sparsely packed porous medium was studied under modulated temperature at the boundaries, and a linear stability analysis has been made. The primary temperature field between the walls of the porous layer consisted of a steady part and a timedependent periodic part and the Galerkin method and the Floquet were used. The critical Rayleigh number was found to be a function of frequency and amplitude of modulation, Prandtl number, porous parameter, diffusivity ratio and solute Rayleigh number.

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Magneto-double diffusive convection in an electrically conducting-fluid-saturated porous medium with temperature modulation of the boundaries

International Journal of Heat and Mass Transfer ◽

10.1016/j.ijheatmasstransfer.2010.01.025 ◽

2010 ◽

Vol 53 (11-12) ◽

pp. 2530-2538 ◽

Cited By ~ 19

Author(s):

B.S. Bhadauria ◽

Atul K. Srivastava

Keyword(s):

Porous Medium ◽

Saturated Porous Medium ◽

Conducting Fluid ◽

Temperature Modulation ◽

Double Diffusive Convection ◽

Electrically Conducting ◽

Electrically Conducting Fluid ◽

Diffusive Convection ◽

Fluid Saturated Porous Medium ◽

Double Diffusive

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Finite Element Study of Double Diffusive Convection and Solidification Under the Combined Influence of Microgravity and Magnetic Fields

Heat Transfer, Volume 7 ◽

10.1115/imece2002-33881 ◽

2002 ◽

Author(s):

K. Li ◽

B. Q. Li ◽

H. C. de Groh

Keyword(s):

Magnetic Field ◽

Finite Element ◽

Magnetic Fields ◽

Space Vehicles ◽

Element Formulation ◽

Double Diffusive Convection ◽

Interface Morphology ◽

Concentration Effects ◽

Diffusive Convection ◽

Double Diffusive

A finite element model is presented for the g-jitter induced double diffusive convection and solidification phenomena with and without the presence of magnetic fields in a Sn-doped Bi single crystal growth system planned for space experiments in space vehicles and the International Space Station. The model is developed based on the deforming finite element formulation with the penalty formulation for pressure approximation and an isothermal front tracking algorithm is used to predict the solid-liquid interface. Extensive numerical simulations are carried out and studied parameters include the effects of solutal striation on the solidification front location and interface morphology under both steady state and g-jitter (or time varying gravity perturbations) conditions with and without the presence of a magnetic field. Both synthesized g-jitter and real g-jitter taken from space flights are used, with the former intended to provide a fundamental understanding of system performance and later to obtain quantitative information in real flight environments. Computed results show that the concentration effects on interface morphology must be considered for an accurate prediction of solidification interface morphology. Also, an applied magnetic field can be very useful means to suppress the deleterious g-jitter induced convection and solutal striation and their effects on solidification.

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