Employing the mass, momentum, and buoyancy conservation laws, together with reasonable assumptions, the governing equations are formulated to simulate gas pipeline leakage in a stratified seawater environment which forming the bubble plume. Calculation of the bubble plume radius and upward velocity are compared with the field experimental data of Fannelop & Sjoen (1980) and Milgram (1983). Numerical simulation results are found in agreement with the field experimental data. Effects of leakage gas flow rate and stratification of ambient seawater on the bubble plume behaviors (such as plume size, intrusion) are investigated and discussed.
Accidents of gas leakage from the pipeline under seawater are occurred occasionally. As a continuous stream of gas is injected into the interior of a liquid, the gas takes the form of bubbles which rise up owing to buoyancy and which impart an upward velocity to the surrounding liquid. It forms a bubble plume. It is known in some respects that a bubble plume in stratified environment is somewhat different from a plume driven by the buoyancy force. For example:
Volume flow rate of gas will increase with height due to the decrease of pressure acting on the gas.
The bubbles will rise faster than the liquid part of the plume surrounding them.
A bubble plume in a stratified environment will continue to rise past any height at which simple plume theory predicts that the plume as a whole would stop rising and would spread out horizontally. For a single-phase plume, it had been studied extensively. Chen and Rodi (1980) made a thorough review on the single-phase jet and plume. For bubble plume, previous works like Kobus (1968), Topham (1975), and Sjoen (1982,1983) were done focusing on the bubble plume in homogeneous ambient.
