Browsing by Author "Huang, Jieh-Chau"

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An investigation of a high temperature difference natural convection in a finite length channel without Bossinesq assumption
(2009-05-01)
Fu, Wu-Shung
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Li, Chung-Gang
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Huang, Chien-Ping
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Huang, Jieh-Chau
;
機械工程學系
For expanding industrial applications of a natural convection in a channel under a high temperature difference, a compressible fluid flow is taken into consideration in governing equations instead of renunciation of the Bossinesq assumption. Due to the slowness of the velocity of fluid in the natural convection, the Roe scheme matching methods of preconditioning and dual-time stepping are used to solve the governing equations. In order to resolve reflections induced by acoustic waves at the boundaries of the channel, non-reflection conditions at the boundaries of the channel are derived. The results show that a more reasonable pressure distribution in the channel is first validated and average Nusselt numbers are expressed in terms of Rayleigh number for a wide range temperature difference. (C) 2009 Elsevier Ltd. All rights reserved.
Enhancement of forced convection heat transfer in a three-dimensional laminar channel flow with insertion of a moving block
(2010-09-01)
Fu, Wu-Shung
;
Huang, Jieh-Chau
;
Li, Chung-Gang
;
機械工程學系
;
Department of Mechanical Engineering
Enhancement of heat transfer rate of a heat surface in a three-dimensional channel flow with insertion of a moving slender block is investigated numerically. A slender block is installed along the direction of the channel flow, and the movement of the slender block is in periodic motion and transverse to the channel flow. Due to the interaction between the channel flow and slender block moving, a large circulation vertical to the channel flow is induced and follows the moving slender block closely. The behaviors of the slender block and circulation destroy and suppress the velocity and thermal boundary layers on the heat surface periodically. These phenomena first observed cause the heat transfer rate of the heat surface to be enhanced especially in the downstream of the heat surface. The maximum magnitude of enhancement in this study is about 50%. (C) 2010 Elsevier Ltd. All rights reserved.