Pump inertia has been calculated manually an checked when calculated by Hammer.
Appreciating your kind assistance please
Emad, when setting a pump as "shut after time delay", the "Time (Delay until shutdown)" represents the time at which the electrical power to the pump stops. The graph you showed is the graph of pump impeller speed. Based on the inertia of the pump (entered in the transient tab of the pump definition), the impeller will take some time to reach zero speed. This also impacts the transient response from the shutdown; typically the bigger the inertia, the longer it takes for the water column and impeller speed to slow, which results in a less severe downsurge wave. See more in our Wiki:
Modeling a pump shut down transient event
How does pump inertia effect the pump calculations during a transient simulation?
Regards,
Jesse DringoliTechnical Support Manager, OpenFlowsBentley Communities Site AdministratorBentley Systems, Inc.