Airflow through microtubes with diameters of 0.287 and 0.409 mm was investigated experimentally and analyzed by Fanno-line flow. Using
precise image-processing analysis, the investigated glass microtubes were
found to have a roundness deviation of 6%. Using the Alpha-step profiler,
the average microtube inner wall surface roughness was obtained below 15
nm. The pressure drop and flow rates were measured to analyze the flow
characteristics.The experimental results indicate that the friction factor fobtained from the Fanno-line flow shows good conformity with the
Poiseuille (f = 64/Re) and Blasius equations (f = 0.316/Re0.25) in both
laminar and turbulent flow. These results illustrate continuity and coherence in this research.