Slip Flow Heat Transfer in Annular Microchannels With Constant Heat Flux

Microscale fluid dynamics has received intensive interest due to the emergence of microelectromechanical systems technology. When the mean free path of the gas is comparable to the channel’s characteristic dimension, the continuum assumption is no longer valid and velocity slip and temperature jump may occur at the duct walls. Slip flow heat transfer in annular microchannels has been examined. The effects of velocity slip and temperature jump on the hydrodynamically and thermally fully developed heat transfer characteristics for laminar flow have been studied analytically. The analysis is carried out for both uniform wall heat flux on one wall, adiabatic on the other wall, and uniform wall heat flux on both walls. The results indicate that the slip flow Nusselt numbers are lower than those for continuum flow and decrease with an increase in Knudsen number for most practical engineering applications. The effects of Knudsen number, radius ratio, and heat flux ratio on heat transfer characteristics are discussed, respectively.