Natural Convection in Porous Triangular Enclosure with a Circular Obstacle in Presence of Heat Generation

Chowdhury, Raju; Khan, Md. Abdul Hakim; Siddiki, Md. Noor-A-Alam

doi:10.11648/j.ajam.20150302.14

Cited by 17 publications

(15 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Natural convective heat transfer characteristics in enclosures have a great significance in industrial applications such as solar collectors, thermal storage systems, cooling of nuclear reactors, etc. In past years, different methods were used to augment the heat transfer in enclosures such as using porous media [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 ] and nanotechnology [ 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 ]. The corrugated annulus is a type of enhanced heat transfer techniques.…”

Section: Introductionmentioning

confidence: 99%

Natural convection heat transfer in corrugated annuli with H2O-Al2O3 nanofluid

Aljabair

Mohammed

Alesbe

2020

Heliyon

View full text Add to dashboard Cite

The present work includes a numerical study of natural convection heat transfer in symmetrical and unsymmetrical corrugated annuli filled with H 2 O-Al 2 O 3 nanofluid. In this study, higher and lower temperatures were kept constant at inner and outer cylinders of the annulus; respectively. Eight mathematical models with an aspect ratio of 1.5 were developed to find the best model giving the highest heat transfer rates. The stream-vorticity formulation in curvilinear coordinates was used to solve the governing equations of heat transfer and fluid motion. The influences of Rayleigh number. ðð10 3 Ra 10 6 Þ and volume fraction of nanoparticles. (0 ϕ 0:25Þ on isotherms, streamlines, local and average Nusselt numbers on the inner and outer cylinder were investigated. The results show that the heat transfer rate is significantly increased with an increase in nanoparticles volume fraction and Rayleigh number. The activity of the heated surface is increased with an increase in the undulation number, but the flow motion tends to be most difficult in the spaces between active undulation walls. Moreover, the heat transfer rates in unsymmetrical annuli are relatively higher than the rates in the symmetrical annuli. There are no evident changes in isotherms with an increase in the nanofluid volume fraction. Correlations for the mean Nusselt number on the inner and outer walls of annulus were deduced as a function of Rayleigh number and nanoparticles volume fraction for eight models with an accuracy range of 8-15 %.

show abstract

Section: Introductionmentioning

confidence: 99%

Natural convection heat transfer in corrugated annuli with H2O-Al2O3 nanofluid

Aljabair

Mohammed

Alesbe

2020

Heliyon

View full text Add to dashboard Cite

show abstract

“…Applications include effective cooling system for electronic components, solar collectors, thermal storage system, nuclear reactors, etc. In recent years, there are many attempts from researchers using different methods to enhance the heat transfer rate using of porous media [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15] and nanotechnology . The present study has used the second method.…”

Section: Introductionmentioning

confidence: 99%

Prediction of Natural Convection Heat Transfer Phenomena of Nanofluids in Corrugated Annulus

Aljobair¹,

Mohammed²,

Alesbe³

2020

Preprint

View full text Add to dashboard Cite

Abstract The natural convection heat transfer and fluid flow characteristic of water based Al2O3 nano-fluids in a symmetrical and unsymmetrical corrugated annulus enclosure has been studied numerically using CFD. The inner cylinder is heated isothermally while the outer cylinder is kept constant cold temperature. The study includes eight models of corrugated annulus enclosure with constant aspect ratio of 1.5. The governing equations of fluid motion and heat transfer are solved using stream-vorticity formulation in curvilinear coordinates. The range of solid volume fractions of nanoparticles extends from PHI=0 to 0.25, and Rayleigh number varies from 104 to 107. Streamlines, isotherms, local and average Nusselt number of inner and outer cylinder has been investigated in this study. Sixty-four correlations have been deduced for the average Nusselt number for the inner and outer cylinders as a function of Rayleigh number have been deduced for eight models and five values of volume fraction of nano particles with an accuracy range 6-12 %. The results show that, the average heat transfer rate increases significantly as particle volume fraction and Rayleigh number increase. Also, increase the number of undulations in unsymmetrical annuli reduces the heat transfer rates which remain higher than that in symmetrical annuli. There is no remarkable change in isotherms contour with increase of volume fraction of nanofluid.

show abstract

“…It was concluded by them due to the presence of the solid adiabatic strip, the lower portion of the cavity remains very cold compared to the upper portion. Chowdhury et al [5] performed natural convection in porous triangular enclosure with a circular obstacle in presence of heat generation. They observed that the fluid flow and temperature field strongly depend on the presence of the circular body obstructs the flow and temperature fields.…”

Section: Introductionmentioning

confidence: 99%

Numerical Simulation of Natural Convection in a Rectangular Cavity with Heated Triangle and Internal Heat Generation

Mollah¹,

Alam²,

Alim³

2019

IJTAM

View full text Add to dashboard Cite

Free convection flow and heat transfer in a rectangular cavity with heated triangle and internal heat generation is investigated numerically. A finite element analysis is performed to investigate the effects of uniform heating and is also used for solving the Navier-Stokes and Energy balance equations. The horizontal bottom wall is divided into three equal sections. The middle section of the horizontal bottom wall, bottom side of the triangle and left vertical left wall in the enclosure were kept temperature at T h . The other two parts of the horizontal bottom wall and the other two sides of the triangle were kept thermal insulation while the right vertical walls and the top wall of the cavity were maintained constant temperature T c with T h >T c . The physical problems are represented mathematically by different sets of governing equations along with corresponding boundary conditions. The dimensionless Parameters in the equations are performed for Heat generation (λ), Rayleigh number (Ra) and Prandtl number (Pr). The streamlines, isotherms, average Nusselt number, velocity profiles and temperature distribution of the fluid in the enclosure are presented graphically. The numerical results indicate that the Heat Generation and Rayleigh number have strong influence on the streamlines and isotherms. Also the mentioned parameters have significant effect on average Nusselt number at the hot wall and average temperature of the fluid in the enclosure.

show abstract

Natural Convection in Porous Triangular Enclosure with a Circular Obstacle in Presence of Heat Generation

Cited by 17 publications

References 19 publications

Natural convection heat transfer in corrugated annuli with H2O-Al2O3 nanofluid

Natural convection heat transfer in corrugated annuli with H2O-Al2O3 nanofluid

Prediction of Natural Convection Heat Transfer Phenomena of Nanofluids in Corrugated Annulus

Numerical Simulation of Natural Convection in a Rectangular Cavity with Heated Triangle and Internal Heat Generation

Contact Info

Product

Resources

About