Centrifugal (Rotodynamic) Pump
This topic pertains to the Pump Curve Analysis Option which represents the real behavior of a centrifugal pump. For Sizing Analyses, see Pump Sizing.
A Pump Curve is required to model a centrifugal pump. This is the typical Head or Pressure vs. Flow information that will be available from any pump manufacturer. Certain features also require the definition of an NPSHR curve, and Power or Efficiency curves.
To enter curves, click Enter Curve Data. Once this data has been defined, previews of the applied curves can be seen here.
These values allow representation of different impeller trims without the need to input new curves.
Ratio as Percent - This option assumes that the pump curve represents 100% trim. Entering different values adjusts the pump curve with the Affinity Laws.
Actual Impeller - Only available if Multiple Configurations are defined. In this case, a dimensional value for impeller size can be entered here.
Represents a pump with a fixed head or pressure at suction. See Submerged Pump.
Model a check valve that can be considered part of the pump itself. If using the XTS Module, a check valve junction will not close until the time step after the reverse flow occurs. However, when used as part of the pump junction it will never allow backflow at any time step.
Forward Velocity to Close - The flow velocity, in the forward direction, that causes the check valve to close preventing any further flow. A negative value in this field indicates reverse flow through the pump.
Delta Head to Re-Open - The differential head or pressure (upstream minus downstream) required to re-open the check valve.
Figure 1: Centrifugal model with a pump curve defined
Represents a multiple stage pump that has some amount of flow removed between the upper and lower stages. See Interstage Bleed/Takeoff Flow.