矩形断面マイクロチャネル内の気液二相流に及ぼす壁面濡れ性の影響

抄録

The characteristics of air-water two-phase flows in microchannels with rectangular cross sections of 1mm × 0.5mm were investigated experimentally. Two channels with different wall wettability were tested. In Case 1, all the channel walls were treated to be hydrophobic by spray coating. In Case 2, three walls were treated to be hydrophilic and one wall was hydrophobic. It was found that water droplets flowed intermittently in Case 1 while liquid film was formed steadily in Case 2. The mean void fraction in Case 1 was much smaller than that in Case 2, but the pressure drop in Case 1 was almost the same as that in Case 2.