PRESSURE DROP FOR SUBSONIC GAS FLOW IN MICROCHANNELS AND NANOCHANNELS

The objective of this article is to furnish the research and design communities with a simple and convenient means of predicting pressure drop for subsonic gas flow in microducts. The pressure drop is utilized to overcome the friction against the walls and simultaneously accelerate the flow to compensate for the decrease in density. A general pressure drop model for approximately isothermal subsonic gas flow in microchannels is proposed. The momentum changes due to gas acceleration along the channel are taken into account. The model is also extended to the transition regime by employing the appropriate second-order slip boundary conditions. As for subsonic gas flow, no solutions or graphical and tabulated data exist for almost all geometries when the outlet Mach number is greater than 0.3. The developed simple model fills this void and can be used for the practical engineering design of microchannels and nanochannels by the research and design communities.