A study has been made of the behavior of gas jet injected into a thin sheet of mercury (i.e., a "two-di-mensional" environment). The vessel was made of acrylate resins. The sheet of mercury was 0.5 cm in thickness. Nitrogen gas (5803 200 cm³/s) was injected into the mercury bath through an orifice of 0.2 cm in diameter. The gas jet behavior was observed by using a high speed camera.
It is observed that, when jetting occurs, many tiny droplets are formed in the gas jet at the orifice exit. The present result for bubbling-jetting transition agrees well with the previous data obtained by three dimensional bath. It is shown that the jetting behavior is determined exclusively by the gas-flow velocity. The injected gas does not form a continuous gas channel even in the sonic velocity region. The injected jet breaks up at some distance from the orifice exit, leaving a gas jet residual. The minimum length of the gas jet residual is fixed for each gas-flow velocity. Thus, it has been found that the gas phase forms a small continuous jet extending from the orifice exit to the top of the jet residual.