Function that implements the second order derivative of IDEAS.Fluid.BaseClasses.FlowModels.basicFlowFunction_m_flow, assuming a constant flow coefficient.
When called with m_flow_der=der(m_flow) and
m_flow_der2=der(m_flow_der), this function returns the
second order derivative of dp with respect to time.
When called with m_flow_der=1 and
m_flow_der2=0, this function returns the second order
derivative of dp with respect to
m_flow.
function basicFlowFunction_m_flow_der2 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 "1st derivative of mass flow rate in design flow direction"; input Real m_flow_der2 "2nd derivative of mass flow rate in design flow direction"; output Real dp_der2 "2nd derivative of pressure difference between port_a and port_b (= port_a.p - port_b.p)"; end basicFlowFunction_m_flow_der2;