2007 年 2 巻 p. 25-32
In the present investigation, detailed observations on the flow patterns and measurements for pressure drop characteristics affected by the curvature effect in a micro-channel were carried out. The test channel has a square cross section that has 2.0 mm on a side, and the radii of the curvature were 1.0 mm and 3.0 mm. It was cleared that the pressure fluctuation intensity became larger in the case of the curvature 1.0mm compared with the case of the curvature 3.0 mm. Furthermore, in order to investigate the influence of the wall wettability, we applied the water repellent micro-channel. In the case of the water repellent micro-channel, the flow pattern tended to easily transit to Annular flow side compared with the normal micro-channel without the water repellent, and we can see a new flow regime like Rivulet flow due to applying water repellent. In addition, the time-averaged pressure drop was decreased in the case of water repellent compared with the case of normal wall. The reason of this is considered that the liquid slug could move easily due to the lower surface tension force at the solid-liquid interface.