The importance of ventilation of sewer systems to avoid air entrapment

Harmful incidents can occur in sewer systems: flooding, sewer overload, geyser phenomenon, etc. These failures occur during intense rainfall events when the flow of wastewater mixed with rainwater overloads the sewer system. The initial objective of the current study is to better understand the flow pattern within the sewer system and then to propose a solution to the flooding phenomena. To this end, we developed a numerical model capable of simulating air-water flow in a confined channel using ANSYS Fluent software. The results showed that the model predicts the flow pattern inside the channels well. In addition, a comparison between a transient simulation on an initially moving air-water flow and a simulation on a resting air-water flow was performed to show the importance of a proper ventilation system in flood prevention.