BuildingSystems.Fluid.BaseClasses.FlowModels.basicFlowFunction_m_flow_der

# .BuildingSystems.Fluid.BaseClasses.FlowModels.basicFlowFunction_m_flow_der

1st derivative of function that computes pressure drop for given mass flow rate

## Information

Function that implements the first order derivative of BuildingSystems.Fluid.BaseClasses.FlowModels.basicFlowFunction_m_flow with respect to the mass flow rate.

#### Interface

>     function basicFlowFunction_m_flow_der
>       extends Modelica.Icons.Function;
>       input Modelica.Units.SI.MassFlowRate m_flow "Mass flow rate in design flow direction";
>       input Real k(unit = "") "Flow coefficient, k=m_flow/sqrt(dp), with unit=(kg.m)^(1/2)";
>       input Modelica.Units.SI.MassFlowRate m_flow_turbulent(min = 0) "Mass flow rate where transition to turbulent flow occurs";
>       input Real m_flow_der(unit = "kg/s2") "Derivative of mass flow rate in design flow direction";
>       output Real dp_der "Derivative of pressure difference between port_a and port_b (= port_a.p - port_b.p)";
>     end basicFlowFunction_m_flow_der;

## Revisions

- January 4, 2019, by Michael Wetter:
  Set `Inline=false`.
  See #1070.
- May 1, 2017, by Filip Jorissen:
  Revised implementation such that BuildingSystems.Fluid.BaseClasses.FlowModels.basicFlowFunction_m_flow is C2 continuous. See #725.
- July 29, 2015, by Michael Wetter:
  First implementation to avoid in Dymola 2016 the warning "Differentiating ... under the assumption that it is continuous at switching".

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