Numerical study of radiative impacts on a magneto-convective flow confined an inclined two-sided wavy enclosure using hybrid nanofluid

The present work shows a numerical study of laminar, steady, and mixed convective flow inside lid-driven square cavity with intruded rectangular fin in its lower surface. The main purpose here is to maximize the heat transfer between the rectangular fin and the surrounding mixed convective flow inside a lid-driven cavity by means of constructal design. The problem is subject to two constraints, the lid-driven cavity and intruded fin areas. The ratio between the fin and cavity areas is kept fixed (ϕ = 0.05). The investigated geometry has one degree-of-freedom (DOF), the fin aspect ratio (H1/L1), which is varied in the range 0.1 ≤ H1/L1 ≤ 10. The aspect ratio of the cavity is maintained fixed (H/L = 1.0). The effect of the fin geometry over the Nusselt number is investigated for several Rayleigh (RaH = 103, 104, 105 and 106) and Reynolds numbers (ReH = 10, 102, 3.0 × 102, 5.0 × 102, 7.0 × 102 and 103). For all simulations, the Prantdl number is fixed (Pr = 0.71). The conservation equations of mass, momentum, and energy are numerically solved with the finite volume method. Results showed that fin geometry (H1/L1) has strong influence over the Nusselt number in the fin. It was also observed that the effect of H1/L1 over Nusselt number changes considerably for different Rayleigh numbers and for the lowest magnitudes of Reynolds numbers, for example, differences of nearly 770% between RaH = 106 and forced convective flow were observed for the lowest Reynolds number studied (ReH = 10).

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Free Convection in a Triangular Cavity Filled with Hybrid-Nanofluid along with Sinusoidal Heat

European Journal of Engineering Research and Science ◽

10.24018/ejers.2019.4.12.1613 ◽

2019 ◽

Vol 4 (12) ◽

pp. 48-52

Author(s):

Md.Rakibul Hasan ◽

Md. Borhan Uddin ◽

Ahmed M. U.

Keyword(s):

Nusselt Number ◽

Rayleigh Number ◽

Hartmann Number ◽

Volume Fraction ◽

Numerical Study ◽

Hybrid Nanofluid ◽

Cool Temperature ◽

Governing Equations ◽

Uniform Cool ◽

Generation Parameter

A numerical study on convective heat transfer of hybrid nanofluid packed in a right angled triangular cavity heated by a sinusoidal temperature maintained from lower side and subjected to a constant magnetic field have been studied in this work. The hypotenuse side of the triangular cavity has been kept in uniform cool temperature while the remaining side is insulated. The governing equations of the problem have been discretized numerically with help of finite element method. A fixed Prandtl number Pr=6.2 has been used for the numerical solution. Several values of Rayleigh number Ra=102-106 , and Hartmann number Ha=0-100 which are the non-dimensional governing parameters have been examined. The volume fraction =0.01, 0.05, 0.1 and the heat generation parameter Q = 1 have been taken for this work. Calculate and the graph of Nusselt number corresponding to different parameters have been presented. The results show that Nusselt number has been decreasing function of nanoparticles Rayleigh number and also it is a decreasing function of Hartmann number. Obtained results has been compared with previously obtained data by other authors.

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Numerical study of magnetohydrodynamic mixed convective flow in a lid-driven enclosure filled with nanofluid saturated porous medium with center heater

Thermal Science ◽

10.2298/tsci171105313n ◽

2019 ◽

Vol 23 (3 Part B) ◽

pp. 1861-1873

Author(s):

Thangavelu Mahalakshmi ◽

Nagarajan Nithyadevi ◽

Hakan Oztop

Keyword(s):

Heat Transfer ◽

Porous Medium ◽

Fluid Flow ◽

Convective Flow ◽

Numerical Study ◽

Bottom Wall ◽

Height Velocity ◽

Flow And Heat Transfer ◽

Mixed Convective Flow ◽

Heater Length

This present numerical study explores the MHD mixed convective flow and heat transfer analysis in a square porous enclosure filled with nanofluid having center thin heater. The left and right walls of the enclosure are maintained at temperature T . The bottom wall is c considered with a constant heat source whereas the remaining part of bottom wall and top wall are kept adiabatic. The finite volume method based on SIMPLE algorithm is used to solve the governing equations in order to investigate the effect of heater length, Hartmann, Richardson, and Darcy numbers on the fluid-flow and heat transfer characteristics inside the enclosure. A set of graphical results are presented in terms of streamlines, isotherms, mid height velocity profiles and average Nusselt numbers. The results reveal that heat transfer rate increases as heater length increases for increasing Darcy and Richardson numbers. Among the two positions of heaters, larger enhancement of heat transfer is obtained for horizontal heater of maximum length. It is observed that, Hartmann number is a good control parameter for heat transfer in fluid-flow through porous medium in enclosure. Moreover, Ag-water nanofluid has greater merit to be used for heat transfer enhancement. This problem may be occurred in designing cooling system for electronic equipment to maximize the efficiency with active and secured operational conditions.

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