NUMERICAL INVESTIGATION OF LAMINAR MIXED CONVECTION IN TROMBE WALL CHANNEL
Main Article Content
Abstract
The two dimensional steady, combined forced and natural convection in vertical channel is
investigated for laminar regime. To simulate the Trombe wall channel geometry properly, horizontal
inlet and exit segments have been added to the vertical channel. The vertical walls of the channel are
maintained at constant but different temperature while horizontal walls are insulated. A finite
difference method using up-wind differencing for the nonlinear convective terms, and central
differencing for the second order derivatives, is employed to solve the governing differential
equations for the mass, momentum, and energy balances. The solution is obtained for stream
function, vorticity and temperature as dependent variables by iterative technique known as successive
substitution with overrelaxation. The flow and temperature patterns in the channel are obtained for
Reynolds numbers and Grashof number ranging from 25 to 100 and (100 to 1,000,00,) respectively.
A computer program ( Fortran 90 ) is built to calculate the fraction factor and the total
average Nusselt number (Nu) also the average heat transfer Q in steady state and for Aspect ratio Ar
(10) and Grashof number GR (10 2 − 10 5 ), the fluid Prandtl number is fixed at (Pr=0.733) and
Reynolds number Re (25-100).
The results show reasonable representation to the relation between Nusselt number and friction
factor with other parameters (Ar, GR and Re). Nu is increased with increasing Re and GR but it
decreases with Ar increase and (Q) is increased with increasing Re ,GR and Ar. At the same time, the
product friction factor(fRe) increased with (GR) and (Ar)increased and (Re )decrease.
Comparison of the result with the previous work shows a good agreement
Article Details
How to Cite
Publication Dates
References
Robert, J. L , and Trombe, F., (1978) "Experimental study of passive Air‐cooled Flat ‐ Plate Solar Collectors: Characteristics
and working Balance in the Obeillo Solar House, " Energy conservation in Heating and cooling and Ventilating Buildings,
Hemisphere Publishing Corp., Washington, Vol. 2, pp. 761‐782
Nogotov, E. F., (1978) Application of Numerical Heat Transfer, Hemisphere Publishing Corp., Washington.
Samarsky, A. A. (1971) " Vvedenie v teoriyu raznostnkyh skhem"( "Introduction to the difference
secheme theory" ) , P. 496, Moskva, Nauka.
Gosman, D., (1969) Heat and Mass Transfer in Recirculating Flows, Academic Press, New York.
Shih T. M, (1984) “Numerical Heat Transfer”, McGraw‐Hill, Washignton,. Davis, G., de Vahl, (1983) "Natural Convection of Air in a Square Cavity: A Bench Mark Numerical Solution," International Journal of Numerical Methods in Fluids, Vol.3, pp. 249‐264.
Chaturvedi, S. K., and Huang, G. C., (1988)"Mixed Laminar convection in Trombe Wall channels" Solar Energy, Vol. 110, pp. 31‐37.
Yasser, A., Al Whabb " Numerical Investigation of Laminar Mixed Convection in Tromb Wall Channel", Department of
Mechanical Engineering, University of Baghdad, M.SC., 2008.