Experimental study on gas flow in quartz microtubes and holey optical fibers

An experimental setup was built to investigate the gas flow characteristics in quartz microtubes with diameters of 20 μm and 50 μm, and in a type of holey optical fiber. The pressure drops between the inlet and outlet were measured with various mass flow rates. The Darcy friction factor and the Poiseuille number dependencies of the Reynolds number were calculated and then compared with numerical simulation results based on Navier-Stokes equations. It was shown from the Knudsen number that the flow partially enters slip regime in the mass flow rate range discussed. The flow resistances in quartz microtubes and holey optical fibers are larger than those in conventional scale channels.