An experimental study of subsonic microjets escaping from a flat nozzle

Abstract

We have experimentally studied subsonic laminar gas jets escaping from a flat nozzle with dimensions of 83.3 × 3600 μm. Reynolds numbers calculated for the given nozzle height and average flow velocity at the nozzle output edge ranged within 58–154. The working gas was air at room temperature. Distributions of the gas velocity and its pulsation along the jet axis were determined. It is established that the obtained characteristics of laminar subsonic microjets are fundamentally different from those of macroscopic turbulent jets. Based on the results of velocity pulsation measurements, it is shown that a laminar–turbulent flow transition is present and its position is determined.