JP Journal of Heat and Mass Transfer
Volume 3, Issue 2, Pages 95 - 115
(June 2009)
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THE CONTRIBUTION OF VELOCITY GRADIENT TO LAMINAR CONVECTIVE HEAT TRANSFER OF A SQUARE DUCT WITH UNIFORM WALL HEAT FLUX
Liang-Bi Wang (P. R. China), Kun Huang (P. R. China), Zhi-Min Lin (P. R. China), Wei-Wei Wang (P. R. China), Liang Hua (P. R. China) and Xiang Wu (P. R. China)
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Abstract: The contribution of the velocity gradient in convective heat transfer is critical to understanding these processes and to connecting convective heat or mass transfer with the energy dissipation in flow. In order to demonstrate the contribution of the velocity gradient, its contribution in laminar convective heat transfer through a square duct with a uniform wall heat flux boundary is examined in detail. The results show that: in a developing region on a wall surface, the velocity gradient contributes to the convection of the heat flux normal to the wall surface; in a developing region and inside flow, both the velocity and the velocity gradient contribute to the convection of the flux in the stream direction; in a fully developed region on the wall surface, the velocity gradient is independent of the stream position, and the velocity gradient contributes only to the convection of the heat flux normal to the wall surface; in a fully developed region and inside flow, the heat flux in the normal direction of the wall surface is transported through convection contributed by the velocity gradient; in a fully developed region and inside flow, the heat flux in the direction of main flow transports through a no-net diffusion and a no-net convection process. |
Keywords and phrases: convective transport, heat transfer, laminar flow, contribution of velocity gradient to convection. |
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