Assigned Flow

The Assigned Flow junction type connects a single pipe and applies a specified steady-state and/or transient flowrate entering or leaving at a location in the system.

The Assigned Flow Properties window follows the first of the two basic Properties window formats, displaying the connecting pipe information in a fixed format.

The Assigned Flow junction type allows specification of positive mass flow rates. Negative flow rates are not accepted for steady flow, but negative flow rates are allowed for transient flow. If the junction is defined as an outflow type and the system is physically flowing in, a negative flow rate cannot be assigned to the junction. The connecting pipe reference flow direction must be reversed to be consistent with the actual flow direction, and the junction must be changed from an outflow type to an inflow type.

Transient Data

On the transient data tab a flowrate transient can be entered. A special feature is the ability to model a sinusoidal flowrate transient. Input for the amplitude and frequency is required. If data is present in the transient data table, the sinusoidal transient is summed with the data in the transient data table.

A chopped sine wave takes the absolute value of the sine function. The end effect looks like doubling the frequency in the positive domain only, and having nothing in the negative domain.

For more information on transient data, including event transients, see Junction Transient Data.

Special Conditions

You can set a Special Condition for an Assigned Flow junction, which will turn the flow off and make it act like a Dead End during steady-state.