Experimental and numerical investigation of forced convective heat transfer in solar air heater with thin ribs

Solar Energy ◽  
2017 ◽  
Vol 147 ◽  
pp. 277-291 ◽  
Author(s):  
Sanjay K. Sharma ◽  
Vilas R. Kalamkar
Keyword(s):  
Heat Transfer ◽  
Convective Heat Transfer ◽  
Numerical Investigation ◽  
Convective Heat ◽  
Solar Air Heater ◽  
Forced Convective Heat Transfer ◽  
Air Heater

Forced Convective Heat Transfer in Cross-Corrugated Solar Air Heaters

1994 ◽  
Vol 116 (4) ◽  
pp. 212-214 ◽  
Author(s):  
Y. Piao ◽  
E. G. Hauptmann ◽  
M. Iqbal
Keyword(s):  
Heat Transfer ◽  
Convective Heat Transfer ◽  
Convective Heat ◽  
Fluid Velocity ◽  
Local Heat Transfer ◽  
Local Heat ◽  
Working Fluid ◽  
Solar Air Heater ◽  
Forced Convective Heat Transfer ◽  
Radiant Heater

Forced convective heat transfer in a cross-corrugated channel solar air heater has been studied experimentally using air as a working fluid. The channel was formed by two transversely positioned corrugated sheets and two flat thermally insulated side walls. One corrugated sheet was heated by a radiant heater, while the other was thermally insulated. The fluid velocity and temperature, and the wall temperature and the local heat flux across the heated corrugated sheet were measured for a variety of operating flow rates. Experimental results for the channel geometry have yielded the correlation Nu=0.0743(Re)0.76. This heat-transfer coefficient is about 2.8 times that of a smooth flat channel. The experiments showed that local heat transfer rate was smaller on the valley of the corrugation than that on the peak. The ratio of the local heat transfer rates on the two locations was related to the Reynolds number.

Numerical Investigation of Buoyancy Effect on Forced Convective Heat Transfer to Supercritical Carbon Dioxide Flowing in a Heated Tube

2018 ◽  
Author(s):  
Liu Sheng-hui ◽  
Huang Yan-ping ◽  
Liu Guang-xu ◽  
Wang Jun-feng
Keyword(s):  
Heat Transfer ◽  
Carbon Dioxide ◽  
Heat Flux ◽  
Supercritical Carbon Dioxide ◽  
Convective Heat Transfer ◽  
Numerical Investigation ◽  
Convective Heat ◽  
Mass Flux ◽  
Buoyancy Effect ◽  
Forced Convective Heat Transfer

Numerical investigation of buoyancy effect on forced convective heat transfer to supercritical carbon dioxide flowing in a vertical tube was carried out. When the mass flux is low and wall heat flux high, it shows that the buoyancy effect is obvious, which might redistribute the radial and axial velocity, even M shaped distribution in the radial direction. When the zero-velocity-gradient region corresponding to the M shaped velocity distribution appears in the edge of viscous layer, the production and diffusion of eddy will be weakened, resulting in heat transfer deterioration. According to the extended simulations based on experimental data, reducing the wall heat flux, adding the mass flux or raising the inlet temperature can relieve the deterioration of heat transfer caused by buoyancy effect.

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