Flow Sink

Overview and Key Concepts

The flow sink is used to destroy material at the boundary of the model. The sink has a maximum input rate at which it will accept material. This rate can be set in the properties window, or changed dynamically during the model run. By default, the maximum input rate is unlimited.


The sink uses the standard events that are common to almost all FloWorks objects. See FloWorks Triggers for an explanation of these events.

Note that the sink only accepts flow input so all events and properties that are related to the output flow, such as the On Output trigger, are not available for this object.


For statistical purposes, the sink's FloWorks state profile will be in one of the following states at various points during a simulation run. The current state can be viewed by clicking on the object and then viewing the Statistics pane in Quick Properties.


The sink is not receiving any flow. This may be because its own input is closed, upstream objects are blocked, or the maximum inflow rate is set to zero.


The sink is receiving a non-zero flow from upstream.


The flow sink tracks the following statistics. These can be viewed by clicking on the object and then viewing the Statistics pane in Quick Properties.


The total amount of flow, measured in fluid units, that has entered the sink.

Flow rate

The current input rate of the sink, measured in fluid units per time unit.


The ratio of the input volume (total amount of inflow) to the maximal possible value for that statistic.

For example, if you run the model for two hours and the maximum flow rate was 10 for one hour and 20 for the second hour, while the actual flow rate was 10 per hour during the whole run, the utilization will be (20 (total flow)) / (10 + 20 (maximal flow)) × 100% ≈ 67%.


The flow sink object uses the following properties panels:

Custom coding

You may control the behavior of the flow sink dynamically by writing FlexScript, for example in a Script window or by changing the code behind one of the options in an object trigger.

The flow sink is an instance of the FlowObject class, see the class reference for information about its properties.