Numerical Investigation of Conjugate Natural Convection Heat Transfer from Discrete Heat Sources in Rectangular Enclosure

The coupling between natural convection and conduction within rectangular enclosure was investigated numerically. Three separate heat sources flush mounted on a vertical wall and an isoflux condition was applied at the back of heat sources. Continuity, momentum and energy conservation equations were solved by using control volume formulation and the coupling of velocity and pressure was treated by using the “SIMPLE” algorithm. The modified Rayleigh number and the substrate/fluid thermal conductivity ratio were used in the range 𝑹𝒂𝒍𝒛∗=𝟏𝟎^𝟒−𝟏𝟎^𝟕 and 𝑹𝒔=𝟏𝟎−𝟏𝟎𝟎𝟎 respectively. The investigation was extended to compare results of FC-77 with Air and also for high values of 𝑹𝒔>𝟏𝟎𝟎𝟎. The results illustrated that, when the modified Rayleigh number increases, dimensionless heat flux and local Nusselt number increases for both fluids. Opposite behaviour for the thermal spreading in the substrate and the dimensionless temperature 𝜽, they were decreased when 𝑹𝒂𝒍𝒛∗ is increased. Also with increasing the substrate/fluid thermal conductivity ratio for a given value of the modified Rayleigh number the thermal spreading in the substrate increased which is the reason of the decrease in the maximum temperature value. The present study concluded that, for high values of 𝑹𝒔>𝟏𝟓𝟎𝟎, the effect of the substrate is negligible.

URI

http://hdl.handle.net/10454/8021

Version

published version paper

Citation

Gdhaidh FS, Hussain K and Qi HS (2014) Numerical Investigation of Conjugate Natural Convection Heat Transfer from Discrete Heat Sources in Rectangular Enclosure. Lecture Notes in Engineering and Computer Science: Proceedings of The World Congress on Engineering 2014, WCE 2014, 2-4 July, 2014, London, U.K., pp.1304-1309. ISBN: 978-988-19253-5-0.

Link to published version

http://www.iaeng.org/publication/WCE2014/WCE2014_pp1304-1309.pdf

Type

Conference paper