functionbasicFlowFunction_dp_der2
2nd derivative of function that computes mass flow rate for given pressure drop
Extends from Modelica.Icons.Function (Icon for functions).
Information
Function that implements the second order derivative of Buildings.Fluid.BaseClasses.FlowModels.basicFlowFunction_dp, assuming a constant flow coefficient.
When called with dp_der=der(dp) and dp_der2=der(dp_der),
this function returns the second order derivative of m_flow
with respect to time.
When called with dp_der=1 and dp_der2=0,
this function returns the second order derivative of m_flow
with respect to dp.
Inputs
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Units.SI.PressureDifference | dp | Pressure difference between port_a and port_b (= port_a.p - port_b.p) | |
| Real | k | Flow coefficient, k=m_flow/sqrt(dp), with unit=(kg.m)^(1/2) | |
| Modelica.Units.SI.MassFlowRate | m_flow_turbulent | Mass flow rate where transition to turbulent flow occurs | |
| Real | dp_der | 1st derivative of pressure difference between port_a and port_b (= port_a.p - port_b.p) | |
| Real | dp_der2 | 2nd derivative of pressure difference between port_a and port_b (= port_a.p - port_b.p) |
Outputs
| Type | Name | Default | Description |
|---|---|---|---|
| Real | m_flow_der2 | 2nd derivative of mass flow rate in design flow direction |
Revisions
-
January 4, 2019, by Michael Wetter:
Set `Inline=false`.
See #1070. -
May 1, 2017, by Filip Jorissen:
Revised implementation such that Buildings.Fluid.BaseClasses.FlowModels.basicFlowFunction_dp is C2 continuous. See #725. -
January 22, 2016, by Michael Wetter:
Corrected type declaration of pressure difference. This is for #404. -
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".