Frictional performance of highly viscous fluid in minichannels

This study is to experimentally examine the frictional characteristics inside minichannels (Dh=0.198–2.01 mm) with water and lubricant oil as the working fluids. Tests were performed in both round and rectangular configurations. The test results indicated a negligible influence of viscosity on the friction factor if the hydraulic diameter is greater than 1.0 mm. In addition, the measured data can be well predicted by the conventional correlation in both laminar and turbulent flow conditions. For rectangular configuration having a gap distance of 0.1 mm, the measured friction factors for water can be roughly predicted by the conventional correlation. However, the measured friction factors for lubricant oil are slightly lower than those of predicted value (10–30% lower). It is likely that this under-prediction is attributable to the viscous heating.