Micro-orifice single-phase flow at very high Reynolds number

Micro-orifice discharge with single-phase liquid flow was experimentally investigated with six circular micro-orifices with diameters of 300 μm and 600 μm. The experiments were carried out with water at high pressure (12 MPa) and high temperature (503 K), such that the Reynolds number varied between 28,000 and 220,000, a range significantly wider than inspected during previous researches on turbulent flow conditions in micro-orifices. The dimensionless pressure drop slightly decreased with increasing Reynolds number, with no apparent influence of the micro-orifice diameter ratio or aspect ratio. Using the newly generated data presented here, the validity of an existing micro-orifice discharge prediction method for turbulent flow conditions was extended to microfluidics applications with very high Reynolds numbers.