Natural convection in the annulus bounded by two wavy wall cylinders having a chemically reacting fluid

Roy, Nepal Chandra

doi:10.1016/j.ijheatmasstransfer.2019.04.133

Cited by 29 publications

(15 citation statements)

References 36 publications

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“…They conducted that an increment in Ra or in Da yield an increase in Nu and fluid flow. (Roy 2019) [14] investigate the flow characteristics of natural convection in an annulus surrounded by two wavy wall cylinders generated by exothermic reaction., their numerical results illustrate that the Frank-Kamenetskii number, the Rayleigh number for thermal diffusion, the buoyancy force parameter, the amplitudes of inner and outer wavy wall cylinders, and the Lewis number all have an effect on the streamlines, isotherms, and isolines of concentration. (Chen et al 2020) [15] investigated a numerical study for force convection in a double pipe heat exchanger filled with metal foam.…”

Section: Introductionmentioning

confidence: 99%

Natural Convection in Annulus Between Two Concentric Cylinders Partially Filled with Metal Foam Distributed with New Suggested Design

Alkinani

Ali

2022

IOP Conf. Ser.: Earth Environ. Sci.

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The investigation of natural convection in an annular space between two concentric cylinders partially filled with metal foam is introduced numerically. The metal foam is inserted with a new suggested design that includes the distribution of metal foam in the annular space, not only in the redial direction, but also with the angular direction. Temperatures of inner and outer cylinders are maintained at constant value in which inner cylinder temperature is higher than the outer one. Naiver Stokes equation with Boussinesq approximation is used for fluid regime while Brinkman-Forchheimer Darcy model used for metal foam. In addition, the local thermal equilibrium condition in the energy equation of the porous media is presumed to be applicable for the present investigation. CFD ANSYS FLUENT software package (version 18.2) is used as a solver to this problem. Various parameters are examined; Rayleigh number, Darcy number, and thermal conductivity ratio to study the effect of them on fluid flow and heat transfer inside the annuli space in the suggested design of metal foam layer. current model is compared with the available published results and good agreement is noticed. Results showed that as Rayleigh number increases the dominated of convection mode increases and Nusselt increases. Also, Nusselt is larger at the higher Darcy and thermal conductivity ratio. It was found that at Rayleigh of 106 and thermal conductivity ratio of 104 Nusselt reach its higher value which is 6.69 for Darcy of 0.1 and 6.77 for Darcy of 0.001. A comparison between this design and the traditional design was established for Darcy 0.001 and thermal conductivity ratio 102, and its showed a good enhancement in Nusselt number and the greatest enhancement percentage was 44% at Rayleigh equal 5*104 while the lowest percentage is 6% for Rayleigh equal106.

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Section: Introductionmentioning

confidence: 99%

Natural Convection in Annulus Between Two Concentric Cylinders Partially Filled with Metal Foam Distributed with New Suggested Design

Alkinani

Ali

2022

IOP Conf. Ser.: Earth Environ. Sci.

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“…Indeed, many experimental and numerical studies have been accomplished to analyze and determine quantitatively the rate of natural-convection heat transfer between two concentric cylinders [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. Mack and Bishop [1] they performed the earlier study of natural-convection between two horizontal concentric cylinders of circular cross-sectional shape.…”

Section: Introductionmentioning

confidence: 99%

“…The research produced the effects Rayleigh number and geometrical parameters (cross-sectional form, aspect ratio, inclination angle) on fluid patterns and temperature distribution. Roy [15] studied the natural-convection reduced by exothermic reaction in a concentric annulus. The cylinders of annulus are circular with some undulations which give a new form of cross-section as oval, cross, star cross-sectional shape.…”

Section: Introductionmentioning

confidence: 99%

Natural-convection of Newtonian fluids between two concentric cylinders of a special cross-sectional form

et al. 2021

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In this paper, we performed a numerical simulation of natural convection of Newtonian fluids between two cylinders of different cross-sectional form. The inner cylinder is supposed to be hot and the outer cylinder is assumed to be cold. The diameter of inner cylinder to the diameter of outer cylinder defines the radii ratio (RR= 2.5). The governing equations describing the physical behavior of fluid flow and heat transfer are solved using finite volume method. The effects of Prandtl number (Pr = 0.71 to 100), Rayleigh number (Ra = 103 to 105) and inclination angle of inner cylinder (? = 0? to 80?) on streamlines, isotherms and dimensionless velocity are presented and discussed. Also, the mean average Nusselt number of inner cylinder is plotted versus the governing parameters. All present simulations are considered in two-dimensions for steady laminar flow regime. The obtained results showed that the flow between cylinders is more stable for the inclination angle ? = 0?. Increase in Rayleigh number increases the heat transfer rate for all values of inclination angle. Furthermore, the effect of Prandtl number on the mean average Nusselt number becomes negligible when Pr is over the value 7.01. For example at Pr = 0.71 and Ra =105, increase in inclination from 0? to 40?decreases the average Nusselt number by 5.4%. A new correlation is also provided to describe the average Nusselt number as function of Pr and Ra at ? = 0?.

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“…The author used the implicit-finite difference method to discretize the equations and represented the solutions through the streamlines, isotherms, and Nusselt numbers at the inner object and outer enclosure surface. The problem presented in Roy 15 was further extended by Roy 16 by considering the convective flow in an annulus of chemically reactive liquids bounded by two wavy wall cylinders. Moreover, a range of different configurations, such as square cavity with single or multiple discrete heating sources, 17–19 partially heated porous enclosures, 20–25 L-shaped cavity, 26,27 X-shaped cavity, 28 cavity with multiple fins, 29 C-shaped cavity 30 has been discussed over the past few decades to show-up the application range of nanofluids under different wall conditions.…”

Section: Introductionmentioning

confidence: 99%

Heat transfer characteristics of nanofluids from a sinusoidal corrugated cylinder placed in a square cavity

Parvin

Roy

Saha

et al. 2021

Proceedings of the Institution of Mechanical Engineers, Part C:

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A numerical study is performed to investigate nanofluids' flow field and heat transfer characteristics between the domain bounded by a square and a wavy cylinder. The left and right walls of the cavity are at constant low temperature while its other adjacent walls are insulated. The convective phenomena take place due to the higher temperature of the inner corrugated surface. Super elliptic functions are used to transform the governing equations of the classical rectangular enclosure into a system of equations valid for concentric cylinders. The resulting equations are solved iteratively with the implicit finite difference method. Parametric results are presented in terms of streamlines, isotherms, local and average Nusselt numbers for a wide range of scaled parameters such as nanoparticles concentration, Rayleigh number, and aspect ratio. Several correlations have been deduced at the inner and outer surface of the cylinders for the average Nusselt number, which gives a good agreement when compared against the numerical results. The strength of the streamlines increases significantly due to an increase in the aspect ratio of the inner cylinder and the Rayleigh number. As the concentration of nanoparticles increases, the average Nusselt number at the internal and external cylinders becomes stronger. In addition, the average Nusselt number for the entire Rayleigh number range gets enhanced when plotted against the volume fraction of the nanofluid.

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Natural convection in the annulus bounded by two wavy wall cylinders having a chemically reacting fluid

Cited by 29 publications

References 36 publications

Natural Convection in Annulus Between Two Concentric Cylinders Partially Filled with Metal Foam Distributed with New Suggested Design

Natural Convection in Annulus Between Two Concentric Cylinders Partially Filled with Metal Foam Distributed with New Suggested Design

Natural-convection of Newtonian fluids between two concentric cylinders of a special cross-sectional form

Heat transfer characteristics of nanofluids from a sinusoidal corrugated cylinder placed in a square cavity

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