Control strategy on the double-diffusive convection in a nanofluid layer with internal heat generation

Mokhtar, Nor Fadzillah Mohd; Khalid, Izzati Khalidah; Siri, Zailan; İbrahim, Zarina Bibi; Gani, Siti Salwa Abd

doi:10.1063/1.4989584

Cited by 13 publications

(5 citation statements)

References 41 publications

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“…By adopting this revised model, they found that the oscillatory instability mode vanishes and the presence of nanoparticles exerts a destabilizing effect on the onset of convection. After this study, most investigations focusing on the stability of nanofluid convection in a horizontal layer employed this revised model to analyze the problems 26–30 except the work 31 . The effect of thermophoresis on nanofluids also has been explored by direct numerical simulation 32,33 .…”

Section: Introductionmentioning

confidence: 99%

The onset of natural convection in a horizontal nanofluid layer heated from below

2021

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A linear stability analysis is performed for the onset of natural convection in a horizontal nanofluid layer heated from below. The motion of nanoparticles is characterized by both the thermophoresis and Brownian diffusion effects. Different from previous studies in the literature, both the dependences of thermophoresis on nanoparticle volume fraction and Brownian motion on temperature are taken into consideration in the theoretical model. The result reveals that the base flow is mainly dominated by the effect of thermophoresis and the Brownian diffusion coefficient can be treated as a constant reasonably when a finite temperature difference is imposed across the nanofluid layer. Accordingly, a novel base solution of nanoparticle volume fraction is derived. It is found that the profile of nanoparticle concentration depends heavily on the magnitude of thermophoretic diffusion, which may exhibit a nonlinear distribution across the nanofluid layer once the effect of thermophoresis is significant. The suspended nanoparticles produce a strong destabilizing effect and a tiny volume fraction of nanoparticles is sufficient to trigger the onset of convection and make the nanofluid layer become unconditionally unstable. The dispersion spectra of unstable modes are demonstrated and the most unstable mode with the maximum growth rate is explored. The growth rate of the most unstable mode is found to increase significantly with increasing nanoparticle concentration, while the influence of heat capacity ratio of nanoparticle to base fluid on the behavior of thermal convection is negligible.

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Section: Introductionmentioning

confidence: 99%

The onset of natural convection in a horizontal nanofluid layer heated from below

2021

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“…Using this technique, information about a phenomenon is deduced based on the premise that it can be written as a dimensionally homogeneous equation with certain variables to obtain a smaller set and identify dimensionless numbers that allow the phenomenon under study to be characterized and simulated. [2][3][4][5][6][7][8][9][10][11][12] The objective of this work is to analyze the use of different nondimensionalization approaches to model the phenomenon of natural convection of an incompressible Newtonian fluid in Cartesian coordinates. The study of this phenomenon is relevant for applications that arise in research and industry.…”

Section: Introductionmentioning

confidence: 99%

“…One of the approaches most widely used by research groups has been the dimensional analysis of the governing equation of the phenomenon. Using this technique, information about a phenomenon is deduced based on the premise that it can be written as a dimensionally homogeneous equation with certain variables to obtain a smaller set and identify dimensionless numbers that allow the phenomenon under study to be characterized and simulated 2–12 …”

Section: Introductionmentioning

confidence: 99%

Comparative analysis of nondimensionalization approaches for solving the 2‐D differentially heated cavity problem

Molina‐Herrera,

Quemada‐Villagómez,

Navarrete‐Bolaños

et al. 2024

Numerical Methods in Fluids

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This work reports a numerical study on the effect of three nondimensionalization approaches that are commonly used to solve the classic problem of the 2‐D differentially heated cavity. The governing equations were discretized using orthogonal collocation with Legendre polynomials, and the resulting algebraic system was solved via Newton–Raphson method with LU factorization. The simulations were performed for Rayleigh numbers between 103 and 108, considering the Prandtl number equal to 0.71 and a geometric aspect ratio equal to 1, analyzing the convergence and the computation time on the flow lines, isotherms and the Nusselt number. The mesh size that provides independent results was 51 × 51. Approach II was the most suitable for the nondimensionalization of the differentially heated cavity problem.

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“…Analysis of the various applications of micropolar fluid mechanics was provided by [2,12] and [18]. [13] investigated the influence of an internal heat source on the initiation of Rayleigh-Bénard convection in order to develop a control strategy method for double-diffusive convection using a nanofluid layer. By concentrating on stationary convection, they demonstrated that internal heat generation causes a positive thermal efficiency while feedback control on the initial stage of double-diffusive convection causes a positive thermal resistance.…”

Section: Introductionmentioning

confidence: 99%

Behaviour of the Onset of Rayleigh-Bénard Convection in Double-Diffusive Micropolar Fluids Under the Influence of Cubic Temperature and Concentration Gradient

Idris,

Alias,

Miqdady

2023

MJMS

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Convection heat transfer especially Rayleigh-Bénard convection plays a significant role either in nature or industry applications. Particularly, in industry, the instability of the Rayleigh-Bénard convection process is important to see whether the quality of final goods is excellent or not. Therefore, in this study linear stability theory has been performed to investigate the influence of cubic temperature gradient and cubic concentration gradient on the onset of convection in a double-diffusive micropolar fluid. By adopting the single-term Galerkin procedure, parameters N1,N3,N5 , and Rs have been analyzed to investigate their influence on the onset of convection. The results found that the coupling parameter N1 and micropolar heat conduction parameter N5 will put the system in stable conditions. Meanwhile, the couple stress parameter N3 and solutal Rayleigh number Rs will destabilize the system. The results also show that by increasing the value of the solutal Rayleigh number Rs , the value of the critical Rayleigh number Rac will decrease. By enclosing the micron-sized suspended particles, we can slow down the process of Rayleigh-Bénard convection in double-diffusive micropolar fluids. It is possible to control the process of the onset of Rayleigh-Bénard convection by selecting suitable non-uniform temperature and concentration gradient profiles.

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Control strategy on the double-diffusive convection in a nanofluid layer with internal heat generation

Cited by 13 publications

References 41 publications

The onset of natural convection in a horizontal nanofluid layer heated from below

The onset of natural convection in a horizontal nanofluid layer heated from below

Comparative analysis of nondimensionalization approaches for solving the 2‐D differentially heated cavity problem

Behaviour of the Onset of Rayleigh-Bénard Convection in Double-Diffusive Micropolar Fluids Under the Influence of Cubic Temperature and Concentration Gradient

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