Influence of wall axial heat conduction on the forced convection heat transfer in rectangular channels

الملخص EN

In this paper the conjugate heat transfer in rectangular channel 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 channels dimensions as in microchannels.

As a results the heat conduction in the walls especially in the axial direction cannot be ignored, since it lead to decrease in the efficiency of heat transfer process.

Also the effect of entrance region is taken into consideration where the flow is assumed developing hydro dynamically 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 shows that the existing of axial heat conduction lead to 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's walls based on most of the affecting parameters.

This correlation can be used accurately to compute the value of axial conduction in rectangular channels