A flow sensor does not affect the behavior of the system at all. This is accomplished by setting the effort at the sensor equal to zero. Thus, a flow sensor is in its effects identical with an effort source of zero effort.
The flow sensor is a passive OnePort element. It inherits the effort and flow variables from the passive OnePort. The flow sensor has an additional output signal, through which it transmits the flow value.
Since the flow sensor computes the effort (by setting it equal to zero), it has a causality stroke away from the sensor element.
Potential variables: e: Bondgraphic effort variable f: Bondgraphic flow variable, normalized positive for flows into the model
Equations:
e = 0