Abstract: Effect of non-condensable gas on pressure oscillation of submerged steam jet is studied experimentally. With the presence of non-condensable gas, the pressure oscillation intensity reduces significantly compared with that of pure steam. As the air mass fraction increases, the axial position of pressure oscillation peak shifts downstream. The oscillation intensity peak value increases with the air mass fraction when the water temperature is below 45℃, while it decreases when the water temperature is higher than 50℃. When the water temperature is within the range between 45 and 50℃, the peak value of oscillation intensity is almost invariant with the air mass fraction. Furthermore, the oscillation frequency decreases with the increase of the air mass fraction, steam mass flux, and subcooled water temperature.

Key words: submerged steam jet, non-condensable gas, pressure oscillation intensity, oscillation frequency