Double diffusive convection and thermodiffusion of fullerene–toluene nanofluid in a porous cavity

Ahadi, Amirhossein; Yousefi, Tooraj; Saghir, M. Ziad

doi:10.1002/cjce.21801

Cited by 17 publications

(11 citation statements)

References 15 publications

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“…The optical properties of the ternary mixture in different cells inside the cell array are provided, Table 2 [3,5,[18][19][20][21][22][23]. In which, @n=@T is the variation of the refractive index due to temperature, and @n=@C is the variation of the refractive index due to concentration variation.…”

Section: Optical Properties Of the Ternary Mixturesmentioning

confidence: 99%

“…In which, @n=@T is the variation of the refractive index due to temperature, and @n=@C is the variation of the refractive index due to concentration variation. The contrast factors are very weak functions of both composition and temperature [9,10,17]; because of that small variation of temperature (~T < 20 8C) and concentration (~C < 0.05), these contrast factor were assumed to be constant [6,9,10] for each specific mixture [18][19][20][21][22][23].…”

Section: Optical Properties Of the Ternary Mixturesmentioning

confidence: 99%

See 1 more Smart Citation

Results on the measurement of the soret coefficients for ternary hydrocarbons mixtures on board ISS

Ahadi

Saghir

2017

Materialwissenschaft Werkst

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The diffusion and thermodiffusion coefficients of binary hydrocarbon mixtures have been measured and analyzed in detail elsewhere, as one step forward here we measured the separation of tetrahydronaphthalene, isobutylbenzene, and dodecane mixture in a ternary hydrocarbon mixture, at five different compositions due to thermal gradients, and we determined the Soret and diffusion coefficients of this mixture. The thermodiffusion experiment was conducted by means of a Mach‐Zehnder Interferometer (MZI) using two wavelengths and in a low gravity environment on board the International Space Station (ISS). Thus, we report the chemical concentration variations of the various cases obtained by the recently developed processing technique. Eventually, based on the transient behavior of the separation of the components, the Soret coefficient of all three components for various compositions of this mixture were measured.

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Section: Optical Properties Of the Ternary Mixturesmentioning

confidence: 99%

Section: Optical Properties Of the Ternary Mixturesmentioning

confidence: 99%

Results on the measurement of the soret coefficients for ternary hydrocarbons mixtures on board ISS

Ahadi

Saghir

2017

Materialwissenschaft Werkst

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“…[3][4][5] While the Soret coefficient is recognized as difficult to determine in ground conditions because of technical constraints in the control of liquid convection and convective instabilities, [6][7][8] in conditions with thermal Rayleigh numbers lower than a critical value, a pure thermodiffusion process occurs in the convectionless regime. [9,10] Thus, two-dimensional refractive index variation in the XZ plate ( Figure 1) is expected inside the cell.…”

Section: Introductionmentioning

confidence: 96%

“…Accurate measurement of the thermodiffusion coefficient is important in oil exploration and in optimal oil recovery, since thermodiffusion causes diffusion fluxes in hydrocarbon reservoirs . While the Soret coefficient is recognized as difficult to determine in ground conditions because of technical constraints in the control of liquid convection and convective instabilities, in conditions with thermal Rayleigh numbers lower than a critical value, a pure thermodiffusion process occurs in the convectionless regime . Thus, two‐dimensional refractive index variation in the XZ plate (Figure ) is expected inside the cell.…”

Section: Introductionmentioning

confidence: 99%

Experimental thermal time estimation for Mach‐Zehnder interferometer to study coupled heat and mass transfer

2015

Self Cite

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In the present investigation, a theoretical approach and experimental models are discussed for estimating the experimental thermal time of an optical digital interferometry experiment. The investigation deals with coupling between heat and mass transfer phenomena. Mach‐Zehnder Interferometry has been found to be an accurate and precise experimental tool for visualizing the thermodiffusion phenomenon inside a parallelepiped cavity, when a thermal gradient is applied to its two opposite sides. Processing the results of this experiment requires distinguishing the two experimental phases: 1) refractive index changes due to change of temperature and 2) refractive index changes due to the separation of the components. We can separate these two phases according to the thermal time of the liquid mixture. In previous studies L2/χ (L = distance between hot and cold sides, χ = thermal diffusivity of the mixture) was used as the thermal time of the liquid. However, due to a high separation rate at the beginning of the thermodiffusion process, an accurate estimation of the thermal time can significantly affect the final result of the interferometry measurements. Here, a theoretical approach and an experimental method were developed to estimate the proper thermal time for this experiment. We also discuss the importance of precisely estimating the thermal time on the experimental results. This study shows that assuming thermal time equals L2/χ may cause noticeable underestimation when measuring the Soret coefficients and maximum separation values.

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“…When the mass diffusion due to temperature gradient occurs, the thermosolutal convection is named thermo-diffusion convection. This phenomenon is behind the occurrence of concentration stratification in an initially homogeneous composition of mixtures (Ahadi et al 2013;Jaber et al 2006). Owing to this phenomenon, thermosolutal separation is used for measurements of the diffusion coefficient, especially in liquid metals and fluids of industrial interest.…”

Section: Introductionmentioning

confidence: 99%

On the Optimization of the Species Separation in an Inclined Darcy-Brinkman Porous Cavity under the Effect of an External Magnetic Field

Hasnaoui¹,

Abdelkhalek²

2018

JAFM

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An investigation is conducted to study analytically and numerically the effect of a magnetic field on the species separation induced by the combined effects of convection and Soret phenomenon in an inclined porous cavity saturated by an electrically conductive binary mixture and provided with four impermeable walls. The long sides of the cavity are subject to uniform heat flux while its short ends are adiabatic. Uniform magnetic field is applied perpendicularly to the heated walls. The mixture satisfies the Boussinesq approximation and the porous medium, modeled according to Darcy-Brinkman's law, is assumed homogeneous and isotropic .The relevant parameters for the problem are the thermal Rayleigh number (RT = 1 to 10 6 ), the Lewis number (Le = 10), the inclination angle of the cavity (θ = 0º to 180), the separation parameter (φ = 0.5), the Darcy number (Da = 10 -5 to 10 3 ), the Hartmann number (Ha = 0 to 100) and the aspect ratio of the cavity (Ar = 12). The limiting cases (Darcy and pure fluid media) are recovered in this study. Optimum conditions leading to maximum separation of species are determined while varying the governing parameters in their respective ranges. Results show that the magnetic field can enhance the species separation in cases where the optimal coupling between thermosolutal diffusion and convection is not achieved in its absence. On the other hand, in cases where this optimal coupling is reached in the absence of the magnetic field, the application of the latter destroys the separation of species.

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Double diffusive convection and thermodiffusion of fullerene–toluene nanofluid in a porous cavity

Cited by 17 publications

References 15 publications

Results on the measurement of the soret coefficients for ternary hydrocarbons mixtures on board ISS

Results on the measurement of the soret coefficients for ternary hydrocarbons mixtures on board ISS

Experimental thermal time estimation for Mach‐Zehnder interferometer to study coupled heat and mass transfer

On the Optimization of the Species Separation in an Inclined Darcy-Brinkman Porous Cavity under the Effect of an External Magnetic Field

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