Gas flow in micro-channels

TLDR

The study investigates low‑Reynolds, high‑subsonic, compressible gas flow in micro‑channels. Experiments used nitrogen, helium, and argon in silicon‑wafer micro‑channels 100 µm wide, 10⁴ µm long, and 0.5–20 µm deep. Knudsen numbers spanned 10⁻³ to 0.4, and the measured friction factor matched theoretical predictions for isothermal, locally fully developed, first‑order slip flow.

Abstract

An experimental and theoretical investigation of low Reynolds number, high subsonic Mach number, compressible gas flow in channels is presented. Nitrogen, helium, and argon gases were used. The channels were microfabricated on silicon wafers and were typically 100 μm wide, 10 4 μm long, and ranged in depth from 0.5 to 20 μm. The Knudsen number ranged from 10 -3 to 0.4. The measured friction factor was in good agreement with theoretical predictions assuming isothermal, locally fully developed, first-order, slip flow.