Skip to main content
Log in

Natural convection in a square enclosure with an internal isolated vertical plate

Natürliche Konvektion in einem quadratischen Horizontalschacht, der eine freistehende, senkrechte Platte enthält

  • Originalarbeiten
  • Published:
Wärme - und Stoffübertragung Aims and scope Submit manuscript

Abstract

Numerical computations were performed for the average Nusselt number at an internal vertical plate situated in a square enclosure, with the inner plate and the bounding wall of the enclosure maintained at uniform but different temperatures. Natural convection occurred in the air which occupied the enclosure space. The position of the inner vertical plate within the enclosure was varied parametrically. The plate height-cavity height ratio was 0.513. For narrow distance between the inner plate and the bounding wall the inner plate Nusselt number was enhanced. Aside from this, the plate average Nusselt number was remarkably insensitive to the plate position. The effect of the Rayleigh number on the velocity and temperature fields and local Nusselt numbers are also discussed. The agreement between the predicted flow pattern forRa=1.1×106 and the flow visualization result was reasonably good.

Zusammenfassung

Eine numerische Untersuchung liefert mittlere Nußelt-Zahlen an einer, in einem quadratischen Horizontalschacht freistehenden, senkrechten Platte, wobei deren Temperatur und die der umgebenden Wände jeweils konstant gehalten werden. Im Luftraum dazwischen stellte sich freie Konvektion ein. Die Position der Platte war veränderlich, ihre Höhe blieb mit 51.3% der Schachthöhe konstant. Rückte die Platte nahe an eine Schachtwand, so erhöhte sich die Nußelt-Zahl auf der dieser zugewandten Seite, während die Gesamt-Nußelt-Zahl bezüglich der Platte fast konstant bleibt. Es wird auch der Einfluß der Rayleigh-Zahl auf das Geschwindigkeitsund Temperaturfeld diskutiert. BeiRa=1.1·106 stimmten die Ergebnisse aus der Berechnung gut mit den experimentellen Befunden einer Strömungsvisualisation überein.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

Abbreviations

a :

distance between vertical plate and side-wall of enclosure thermal diffusivity (in definition ofu r)

b :

distance between vertical plate and bottom of enclosure

g :

gravitational acceleration

G :

characteristic flow rate

H :

height of vertical plate

k :

thermal conductivity

k f :

fluid thermal conductivity

K :

relative thermal conductivity,k/k f

L :

width of square enclosure

M res :

mass residual

Nu :

local Nusselt number

Nu m :

average Nusselt number

Nu L :

local Nusselt number of left side of vertical plate

Nu R :

local Nusselt number of right side of vertical plate

Nu B :

local Nusselt number of bottom side of vertical plate

Nu T :

local Nusselt number of top side of vertical plate

p′ :

effective pressure

P :

dimensionless pressure,P=p′/[ϱ(Ra Pr)(a/H)2]

Pr :

Prandtl number

Ra :

Rayleigh number,Ra=gβΔTH 3 Pr/ν 2

T :

temperature

T i :

temperature of internal plate

T o :

temperature of enclosure surface

u, v :

velocity components inx-, y-direction

U, V :

dimensionless velocities,U=u/u r, V=v/ur

u r :

reference velocity,u r=(Ra Pr)1/2/(a/H)

X, {iyY}:

dimensionless coordinates,X=x/H, Y=y/H

α :

heat transfer coefficient

β :

volume expansion coefficient

δ :

thickness of plate

ν :

kinematic viscosity

ϱ :

density

Φ :

dimensionless temperature, (T i−T)/(T i−To)

References

  1. Powe, R. E.; Carley, C. T.; Bishop, E. H.: Free convective flow pattern in cylindrical annuli. ASME J. Heat Transfer 91 (1969) 310–314

    Google Scholar 

  2. Weber, N.; Powe, R. E.; Bishop, E. H.; Scanlan, J. A.: Heat transfer by natural convection between vertical eccentric spheres. ASME J. Heat Transfer 95 (1973) 47–52

    Google Scholar 

  3. Kuehn, T. H.; Goldstein, R. J.: An experimental and theoretical study of natural convection in the annulus between horizontal concentric cylinders. ASME J. Heat Transfer 74 (1976) 695–719

    Google Scholar 

  4. Kuhen, T. H.; Goldstein, R. J.: An experimental study of natural convection in concentric and eccentric horizontal cylindrical annuli. ASME J. Heat Transfer 100 (1978) 635–640

    Google Scholar 

  5. Projahn, V.; Rieger, H.; Beer, H.: Numerical analysis of laminar natural convection between concentric and eccentric cylinders. Numerical Heat Transfer 4 (1981) 131–146

    Google Scholar 

  6. Chang, K. S.; Won, Y. H.; Cho, C. H.: Patterns of natural convection around a square cylinder placed concentrically in a horizontal cylinder. ASME J. Heat Transfer 105 (1983) 273–280

    Google Scholar 

  7. Prusa, J.; Yao, L. S.: Natural convection heat transfer between eccentric horizontal cylinders. ASME J. Heat Transfer 105 (1983) 109–116

    Google Scholar 

  8. Sparrow, W. M.; Charmchi, M.: Natural convection experiments in an enclosure between encentric and concentric vertical cylinders of different height and diameter. Int. J. Heat Mass Transfer 26 (1983) 133–143

    Google Scholar 

  9. Lee, T. S.: Computational and experimental studies of convective fluid motion and heat transfer in inclined non-rectangular enclosures. Int. J. Heat Fluid Flow 5 (1984) 29–36

    Google Scholar 

  10. Khan, J. A.; Kumar, R.: Natural convection in vertical annuli: a numerical study for constant heat flux on the inner wall. ASME J. Heat Transfer 111 (1989) 909–915

    Google Scholar 

  11. Zhang, H. L.; Wu, Q. J.; Tao, W. Q.: Experimental study of natural convection heat transfer between cylindrical envelope and an internal concentric heated octagonal cylinders with or without slots. ASME J. Heat Transfer 113 (1991) 110–121

    Google Scholar 

  12. Glapke, E. K.; Asfaw, A.: Prediction of two-dimensional natural convection in enclosures with inner bodies of arbitrary shapes. Numerical Heat Transfer 20 (1991) Part A, 279–296

    Google Scholar 

  13. Lacroix, M.: Natural convection heat transfer around two heated horizontal cylinders inside a rectangular cavity cooled from above. Numerical Heat Transfer 21 (1992) Part A, 37–54

    Google Scholar 

  14. Yang, M.; Tao, W. Q.: A numerical study of natural convection heat transfer in a cylindrical envelope with internal concentric slotted hollow cylinder. Numerical Heat Transfer 22 (1992) Part A, 289–306

    Google Scholar 

  15. Sparrow, E. M.; Stryker, P. C.; Ansari, M. A.: Natural convection in enclosures with off-center innerbodies. Int. J. Heat Mass Transfer 27 (1984) 49–56

    Google Scholar 

  16. Warrington, R. O.; Crupper, G.: Natural convection heat transfer between cylindrical tube bundle and a cubical enclosure. ASME J. Heat Transfer 103 (1981) 103–107

    Google Scholar 

  17. Warrington, R. O.; Pow, R. E.: The transfer of heat by natural convection between bodies and their enclosures. Int. J. Heat Mass Transfer 28 (1985) 319–330

    Google Scholar 

  18. Adlam, J. H.: Computation of two dimensional time dependent natural convection in a cavity where there are internal bodies. Computers & Fluids 14 (1986) 141–149

    Google Scholar 

  19. Yang, M.; Tao, W. Q.; Wang, Q. W.; Lue, S. S.: On identical problems of natural convection in enclosures and applications of the identical character. To be published in the J. of Thermal Science.

  20. Patankar, S. V.: Numerical heat transfer and fluid flow, Hemisphere. Washington, D.C., 1980

    Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Rights and permissions

Reprints and permissions

About this article

Cite this article

Wang, Q.W., Yang, M. & Tao, W.Q. Natural convection in a square enclosure with an internal isolated vertical plate. Wärme- und Stoffübertragung 29, 161–169 (1994). https://doi.org/10.1007/BF01548600

Download citation

  • Received:

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF01548600

Keywords

Navigation