The Study of Axial Heat Conduction with Various Hydraulic Diameters of Microchannel

This study presents the discussion of axial heat conduction in different hydraulic diameters of rectangular polydimethylsiloxane (PDMS) microchannels at a Reynolds number of 15. The hydraulic diameters of selected microchannel devices vary from 40 to 196 μm with an aspect ratio (i.e. height/width) of 0.1. The temperature data were acquired by the molecule-based temperature sensors technique with both fluid and surface temperature measurements. The temperature variation inside the microchannel shows enhanced temperature increase at channel inlet in the microchannel with hydraulic diameter of 40 μm due to axial heat conduction effect. From these results, it can be concluded that the smaller hydraulic diameter cause the more severe influence of axial heat conduction.