Abstract
An effect of dissolved air on bubble growth from hydrophobic spots has been experimentally studied. Experiments were conducted using pure water at a subcooling of 20 K and the atmospheric pressure. Dissolved air produces negative wall superheats at the bubble incipience from hydrophobic spots and enhances bubble growth. The shape of bubbles attaching on the hydrophobic spots are also different between an open and closed conditions. It is assumed that this difference is caused by existence of air inside the bubble. In the open condition, the bubble consists of vapor and air and saturated temperature of the bubble is lower than saturated temperature of pure vapor, therefore the bubble grows over superheated liquid layer.
