Numerical investigation of double-diffusive (natural) convection in vertical annuluses with opposing temperature and concentration gradients

Chen, Sheng; Tölke, Jonas; Krafczyk, Manfred

doi:10.1016/j.ijheatfluidflow.2009.12.013

Cited by 107 publications

(58 citation statements)

References 24 publications

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“…Several researchers have carried out analysis on second law analysis such as [13][14][15][16]. Furthermore, starting from the pioneering work of Bejan [17][18], several investigations on entropy generation on fluid flow under various physical situations have been done [19][20][21][22][23][24][25][26][27][28][29][30]. Chen [31] performed a detailed study on the effects of Reynolds number and Grashof number on entropy generation inside disk driven convectional flow for the first time.…”

Section: Introductionmentioning

confidence: 99%

Combined Effect of Buoyancy Force and Navier Slip on Entropy Generation in a Vertical Porous Channel

Eegunjobi

Makinde

2012

Entropy

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Abstract:In this paper, we investigate the combined effects of buoyancy force and Navier slip on the entropy generation rate in a vertical porous channel with wall suction/injection. The nonlinear model problem is tackled numerically using Runge-Kutta-Fehlberg method with shooting technique. Both the velocity and temperature profiles are obtained and utilized to compute the entropy generation number. The effects of slip parameter, Brinkmann number, the Peclet number and suction/injection Reynolds number on the fluid velocity, temperature profile, Nusselt number, entropy generation rate and Bejan number are depicted graphically and discussed quantitatively.

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Section: Introductionmentioning

confidence: 99%

Combined Effect of Buoyancy Force and Navier Slip on Entropy Generation in a Vertical Porous Channel

Eegunjobi

Makinde

2012

Entropy

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“…They addressed the oscillatory behaviour of the convection cells with change in buoyancy ratio parameter N. Hyun and Lee (1990) made an attempt to understand the nature of DDNC in the case of rectangular enclosure and exposed the major discrepancies in evolution pattern between cooperating and opposing flows through stream lines ,temperature and concentration plots. More extensive study on the effect of different parameters on DDNC phenomenon was carried out by Chen et al (2010). They have chosen higher Rayleigh number regime (10 6 and 10 7 ), different aspect ratios (0.5-2.0) and buoyancy ratios(0.8<N<1.3).…”

Section: Introductionmentioning

confidence: 99%

Finite Element Study of DDNC in Bottom Heated Enclosures With Mass Diffusive Side Walls

Reddy¹,

Murugesan²

2017

Frontiers in Heat and Mass Transfer

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In this paper DDNC phenomenon in a bottom heated enclosure exposed to mass diffusion from its side walls is investigated numerically. The interplay between thermal and solutal buoyancy forces on fluid circulation and heat transfer rates is studied in three different enclosures of aspect ratios 0.5, 1.0 and 2.0. Finite element base numerical code has used to solve the governing equations, here velocity and vorticity are taken as primary variables for flow field. Numerical results are well validated with that of the literature. The relative strength of solutal to thermal buoyancy forces is defined by buoyancy ratio parameter 'N', numerical investigations were carried out for different values of N in the range of 0 to 10 and three different Rayleigh numbers(Ra=1.0×10 . From results it is observed that solutal buoyancy forces broken down the larger fluid cells and promoted local circulations of stronger strength. Increase in contribution of solutal buoyancy force has resulted in a maximum of 12.6%, 14.5% and 51% increase in average Nusselt number for shallow, square and deep enclosures respectively when heat transfer is primarily by convection while the effect of buoyancy ratio is not felt much on heat transfer at diffusion dominant conditions i.e at Ra=1.0×10 3 .

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“…Experimental data reported in [2][3][4][5][6] in their physical meaning resemble the problem of instability which arises under conditions of thermal convection [8][9][10]. Application of stability theory [11] allowed formulating an approach to revealing common regularities in determining the transition from the diffusion regime to the gravitational concentration convection.…”

Section: Introductionmentioning

confidence: 99%

Study of Diffusion Instability in Some Ternary Gas Mixtures at Various Temperatures

Kossov¹,

Kulzhanov²,

Poyarkov³

et al. 2013

MME

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Within the linear theory of stability, the process of isothermal mixing of three-component gas mixtures in a channel of final dimensions in the absence of mass-transfer through its walls is considered. The comparison of experimental data with the results of theoretical calculations for the mixtures He+Ar-N 2 and H 2 +N 2 -CH 4 is shown, that a stable diffusion process as the temperature increased will remain the same and be described by the ordinary diffusion laws, but unstable one lost its intensity and tend to the stable diffusion.

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Numerical investigation of double-diffusive (natural) convection in vertical annuluses with opposing temperature and concentration gradients

Cited by 107 publications

References 24 publications

Combined Effect of Buoyancy Force and Navier Slip on Entropy Generation in a Vertical Porous Channel

Combined Effect of Buoyancy Force and Navier Slip on Entropy Generation in a Vertical Porous Channel

Finite Element Study of DDNC in Bottom Heated Enclosures With Mass Diffusive Side Walls

Study of Diffusion Instability in Some Ternary Gas Mixtures at Various Temperatures

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