This example compares the power consumed by pumps that take three different control signals. Each pump has identical mass flow rate and pressure rise.
Note that for the instances Annex60.Fluid.Movers.FlowControlled_dp
and Annex60.Fluid.Movers.FlowControlled_m_flow,
we had to assign the efficiencies (otherwise the default constant
efficiency of 0.7 would have been used). In these models,
the power consumption is computed using similarity laws, but using
the mass flow rate as opposed to the speed, because speed is not
known in these two models. This is an approximation at operating
points in which the speed is different from the nominal speed
N_nominal because similarity laws are valid for speed
and not for mass flow rate.
The figure below shows the approximation error for the power calculation where the speed Nrpm differs from the nominal speed Nnominal.

| Name | Description |
|---|---|
| Medium model |
pump_dp and pump_m_flow,
because using a parameter and assigning this
parameter leads in OpenModelica to the error message
expected subtype of record
Annex60.Fluid.Movers.Data.Generic.