Buoyancy and radiation effects on low velocity flows in an asymmetrically heated channel
Combined effects of buoyancy and radiation for low velocity turbulent flow in an asymmetrically heated channel were investigated to provide basic information for analyzing heat transfer in a flat plate solar collector. An asymmetrically heated channel was constructed and instrumented to measure air temperature and velocity profiles and surface temperatures. Heat transfer within the channel was then analyzed over the fully developed region. Experimental Nusselt number results for the heated lower surface showed that buoyancy increased heat transfer as compared to turbulent forced convection. Buoyancy from the upper surface reduced heat transfer as compared to turbulent forced convection. Within the channel, thermal radiation effectively redistributed energy from the lower surface to the upper and side surfaces. When compared to the lower surface heating rate, the percent radiation transferred from the lower surface to the other channel surfaces over the fully developed region averaged 34.4%. The percent radiation received by the upper surface averaged 29.4% with 85.7% being convected into the air stream.
- Research Organization:
- North Carolina State Univ., Raleigh (USA)
- OSTI ID:
- 6516022
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
141000* -- Solar Collectors & Concentrators
42 ENGINEERING
420400 -- Engineering-- Heat Transfer & Fluid Flow
CONVECTION
ENERGY TRANSFER
EQUIPMENT
FLAT PLATE COLLECTORS
FLUID FLOW
FORCED CONVECTION
HEAT TRANSFER
MASS TRANSFER
NUSSELT NUMBER
RADIATIONS
SOLAR COLLECTORS
SOLAR EQUIPMENT
TEMPERATURE MEASUREMENT
TURBULENT FLOW