The microchannel is an integral part of various micro systems.The flow characteristics of nitrogen in three different microchannels(hydraulic diameter of 30~3000 μm) were numerically investigated with consideration of the effect of compressibility and viscosity heating.The effects of size and Reynolds number(Re) on pressure drop
friction factor and friction constant were investigated.Especially
the priority of the research was placed on the effect of ratio of length
entrance/exit
compressibility and viscosity heating.The calculated results show that transition Re is brought forward to about 1 200 in 300 μm microchannels.