NUMERICAL STUDY OF ENHANCED HEAT TRANSFER BY COUPLING NATURAL AND ELECTRO-CONVECTIONS IN A HORIZONTAL ENCLOSURE

2011 ◽  
Vol 18 (6) ◽  
pp. 503-511 ◽  
Author(s):  
R. Ghazi ◽  
Mohammad S. Saidi ◽  
Mohammad Hasan Saidi
Keyword(s):  
Heat Transfer ◽  
Numerical Study ◽  
Enhanced Heat Transfer

Experimental and Numerical Study on Enhanced Heat Transfer of Solid-Liquid PCM by Ultrasonic Wave

2006 ◽  
Vol 326-328 ◽  
pp. 1145-1148
Author(s):  
Ho Dong Yang ◽  
Yool Kwon Oh
Keyword(s):  
Heat Transfer ◽  
Acoustic Pressure ◽  
Numerical Study ◽  
Acoustic Streaming ◽  
Melting Process ◽  
Oscillating Flow ◽  
Enhancement Ratio ◽  
Ultrasonic Vibrations ◽  
Enhanced Heat Transfer ◽  
Solid Liquid

The present study is investigated the causes of enhanced heat transfer during the melting process of solid-liquid PCM (Phase Change Material) using an ultrasonic vibration. Paraffin (noctadecane) was selected as a PCM and experimental studies were performed as following. Heat transfer coefficient and enhancement ratio of heat transfer was measured, acoustic streaming induced by ultrasonic waves observed using a PIV (Particle Image Velocimetry) and thermally oscillating flow phenomenon observed using an infrared thermal camera during the melting process. For the numerical study, a coupled FE-BEM (Finite Element-Boundary Element Method) was applied to investigate acoustic pressure occurred by acoustic streaming in a medium. And then, the profiles of pressure variation compared with the enhancement ratio of heat transfer. The results of this study revealed that ultrasonic vibrations accompanied the effects like acoustic streaming and thermally oscillating flow. Such effects are a prime mechanism in the overall melting process when ultrasonic vibrations are applied. Also, as the acoustic pressure occurred by acoustic streaming increases, the higher enhancement ratio of heat transfer is obtained.

Numerical Study of Enhanced Heat Transfer and Flow of Water-glycol Mixture in Transversely Ribbed Circular Tubes

2010 ◽  
Author(s):  
H. X. Zhao ◽  
J. T. Han ◽  
Z. T. Yu ◽  
L. Shao ◽  
M. X. Wang ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Numerical Study ◽  
Enhanced Heat Transfer ◽  
Circular Tubes
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