A bubble curtain is a system that produces bubbles in a deliberate arrangement in water. This technique is based on bubbles of air (gas) under the water surface that act commonly as a barrier. When the bubbles rise they act as a barrier or a curtain. Bubble curtain is applied for breaking the propagation of waves or prevention of the spreading of particles and other contaminants. This paper paid to applications of this system for prevention of the advance of seawater in tidal estuaries and protection of environment of offshore. The multiphase flow is simulated by computational fluid dynamics method in estuary of tidal rivers. During high level of tide bubble curtain system can be used simultaneous in several parallel rows of air injection in across the river. During low level of tide air injection rate and use of the bubble curtain system is reduced. The results of the numerical models show that increasing air injection rate is caused to reduce seawater intrusion to estuary of tidal rivers.
