Influence of Wall Axial Heat Conduction on the Forced Convection Heat Transfer in Rectangular Channels

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  Mushtaq Ismael Hasan   |   

In this paper, the conjugate heat transfer in rectangular channels is numerically investigated, where the effect of both axial heat conduction and entrance region on the internal forced convection in rectangular channels are studied. With decreasing the dimensions of channels the thickness of walls become large and in order of the dimensions of the channel as in microchannels. As a result, the heat conduction in the walls, especially in the axial direction, can not be ignored, since it leads to a decrease in the efficiency of the heat transfer process. Also, the effect of the entrance region is taken into consideration where the flow is assumed to develop hydrodynamically and thermally. A finite volume method is used to numerically solve the conjugate heat transfer in both the fluid and wall simultaneously. The results obtained show that the existence of axial heat conduction leads to a reduction in the heat transfer and its effect increased with increasing the thickness of walls and Reynolds number. In this paper, a correlation has been developed to calculate the value of axial heat conduction in channel walls based on most of the affecting parameters. This correlation can be used accurately to compute the value of axial conduction in rectangular channels.