Experimental investigation of mixed convection heat transfer in a rectangular channel with discrete heat sources at the top and at the bottom

• Published in: International communications in heat and mass transfer Vol. 32; no. 9; pp. 1244 - 1252
• Main Authors: Dogan, A., Sivrioglu, M., Baskaya, S.
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Ltd 01-10-2005; Elsevier
• Subjects: Applied sciences; Channel flow; Convective and constrained heat transfer; Design. Technologies. Operation analysis. Testing; Discrete heat sources; Electronic cooling; Electronics; Exact sciences and technology; Fundamental areas of phenomenology (including applications); Heat transfer; Integrated circuits; Mixed convection; Natural convection; Physics; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Mixed convection; Discrete heat sources; Channel flow; Electronic cooling; Horizontal pipe; Rectangular pipe; Combined convection; Cooling by air; Nusselt number; Test facility; Electronic component; Experimental study; Heat transfer
• ISSN: 0735-1933; 1879-0178
• DOI: 10.1016/j.icheatmasstransfer.2005.05.003

Mixed convection heat transfer in a top and bottom heated rectangular channel with discrete heat sources has been investigated experimentally for air. The lower and upper surfaces of the channel were equipped with 8
×
4 flush-mounted heat sources subjected to uniform heat flux. Sidewalls, the lower and upper walls were insulated and adiabatic. The experimental study was made for an aspect ratio of AR
=
6, Reynolds numbers 955
≤
Re
Dh
≤
2220 and modified Grashof numbers
Gr*
=
1.7
×
10
7 to 6.7
×
10
7. From experimental measurements, surface temperature and Nusselt number distributions of the discrete heat sources were obtained for different Grashof numbers. Furthermore, Nusselt number distributions were calculated for different Reynolds numbers. Results show that surface temperatures increase with increasing Grashof number. The row-averaged Nusselt numbers first decrease with the row number and then, due to the increase in the buoyancy affected secondary flow and the onset of instability, they show an increase towards the exit as a result of heat transfer enhancement.