Can I see air shape in pipeline in transient in Bentley hammer?

Hello,

By default, HAMMER has limited tracking of air pockets. It assumes that they only exist at the point of formation. You can use the "Extended CAV" calculation option to enable HAMMER to track the air-liquid interface (and therefore the "shape" of the pocket) but that only supports the two adjacent pipes, and only of the two adjacent nodes are at a lower elevation. See more in these articles:

Assumptions and limitations of tracking air or vapor pockets in HAMMER

User Notification "Concentrated CAV model must be used..."

Typically in a transient simulation, the important thing is the speed of the air release (and adjacent water column collision) at the moment that all of the air is released. In a case of a vacuum breaker with no air release, the impact of how the air pocket moves in the system is not analyzed. You may need to think about what potential transient impact it might have in the system (how would it eventually be released?) and use an appropriate approximation for a transient simulation to check that.

Hello,

By default, HAMMER has limited tracking of air pockets. It assumes that they only exist at the point of formation. You can use the "Extended CAV" calculation option to enable HAMMER to track the air-liquid interface (and therefore the "shape" of the pocket) but that only supports the two adjacent pipes, and only of the two adjacent nodes are at a lower elevation. See more in these articles:

Assumptions and limitations of tracking air or vapor pockets in HAMMER

User Notification "Concentrated CAV model must be used..."

Typically in a transient simulation, the important thing is the speed of the air release (and adjacent water column collision) at the moment that all of the air is released. In a case of a vacuum breaker with no air release, the impact of how the air pocket moves in the system is not analyzed. You may need to think about what potential transient impact it might have in the system (how would it eventually be released?) and use an appropriate approximation for a transient simulation to check that.