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