Buoyancy effects in the entrance region of an inclined multirectangular channel solar collector

Journal Article · Sun May 01 04:00:00 EDT 1983 · J. Sol. Energy Eng.; (United States)

DOI:https://doi.org/10.1115/1.3266359· OSTI ID:5378344

Morcos, S M; Abou-Ellail, M M.M.

A numerical procedure is presented for the entrance region of an inclined multirectangular-channel solar collector with significant buoyancy effects. The upper wall heat flux is taken to be uniform, while the lower wall is assumed to be insulated. The heat flux distribution on the side wall of the rectangular channel is obtained by coupling a heat-conduction numerical procedure in the metallic region surrounding the channel to the main numerical procedure which solves the hydrodynamic and energy equations of the flow inside the channel. Numerical results are presented for water flowing in a multirectangular-channel solar collector with an aspect ratio AR = 4 inclined at an angle alpha = 30 degrees to the horizontal. The resulting variable heat flux distribution on the side wall enhances the intensity of the secondary flow. The effects of the nonuniform heat flux distribution and the spacing between the rectangular channels on the variation of Nusselt number in the entrance region are presented for different values of Rayleigh number. At a value of Ra = 5 x 10/sup 5/, Nusselt number is more than three hundred percent above the constant property prediction.

• Research Organization: Mechanical Engineering Department, Cairo University, Cairo
• OSTI ID: 5378344
• Journal Information: J. Sol. Energy Eng.; (United States), Journal Name: J. Sol. Energy Eng.; (United States) Vol. 105:2; ISSN JSEED
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
141000* -- Solar Collectors & Concentrators
CHANNELING
CONFIGURATION
DISTRIBUTION
EQUATIONS
EQUIPMENT
FLUID FLOW
FLUID MECHANICS
HEAT FLUX
HYDRODYNAMICS
INCIDENCE ANGLE
INCLINATION
MECHANICS
NUSSELT NUMBER
PHYSICAL PROPERTIES
RECTANGULAR CONFIGURATION
SOLAR COLLECTORS
SOLAR EQUIPMENT
SPATIAL DISTRIBUTION
THERMAL CONDUCTIVITY
THERMODYNAMIC PROPERTIES
WALLS