Modelica标准库组件AbruptAdaptor

经测试：

MSL版本：

• 3.2.1,2013-08-14，build 2（2013-08-14 08：44：41Z）

• 3.2.1,2013-08-14，build 4（2015-09-30 09：15：00Z）

下面是一个包含4个组件的模型：

• 质量流量源（M_bound）

• AbruptAdapter（abruptAdapter）

• 动态管道（pipeSmall）

• 压力源（P_bound）

该模型的两个连接案例也包含在 equation 部分中：

案例＃1：M_bound - > abruptAdaptor - > pipeSmall - > P_bound

案例＃2：M_bound - > pipeSmall - > abruptAdaptor - > P_bound

Summary ：案例＃1模拟正常，但案例＃2失败 . 生成的错误如下所示：

The following error was detected at time: 0

Model error - division by zero: (data.zeta1) / ((if data.zeta1_at_a then rho_a_des*A_a^2 else rho_b_des*A_b^2)) = (0.402964) / (0)

The stack of functions is:
Modelica.Fluid.Fittings.BaseClasses.QuadraticTurbulent.pressureLoss_m_flow_totalPressure
Modelica.Fluid.Fittings.BaseClasses.QuadraticTurbulent.pressureLoss_m_flow_totalPressure(
 -pipeBig.port_b.m_flow, 
abruptAdaptor.state_a.d, 
abruptAdaptor.state_b_des.d, 
abruptAdaptor.state_b.d, 
abruptAdaptor.state_a_nondes.d, 
abruptAdaptor.data, 
abruptAdaptor.m_flow_small)
First evaluation failed for non-linear solver.

Question ：为什么案例＃2失败并提出如何解决问题的建议？任何见解都会很棒 . 它甚至可能是 AbruptAdaptor 组件中的错误 .

型号代码

model AbruptAdaptor_1Pipe

  replaceable package Medium = Modelica.Media.Water.StandardWater;

  inner Modelica.Fluid.System system;

  Modelica.Fluid.Sources.Boundary_pT P_bound(
    redeclare package Medium = Medium,
    nPorts=1,
    p=system.p_ambient,
    T=M_bound.T);

  Modelica.Fluid.Sources.MassFlowSource_T M_bound(
    redeclare package Medium = Medium,
    m_flow=1,
    T=300,
    nPorts=1);

  Modelica.Fluid.Fittings.AbruptAdaptor abruptAdaptor(
    redeclare package Medium = Medium,
    diameter_a=1,
    diameter_b=0.5,
    m_flow_nominal=M_bound.m_flow,
    m_flow_start=M_bound.m_flow);

  Modelica.Fluid.Pipes.DynamicPipe pipeSmall(
    redeclare package Medium = Medium,
    T_start=M_bound.T,
    m_flow_start=M_bound.m_flow,
    length=1,
    diameter=0.5,
    modelStructure=Modelica.Fluid.Types.ModelStructure.av_b); // switch to av_vb with case #2

equation 

  // Case #1
  connect(M_bound.ports[1],abruptAdaptor.port_a);
  connect(abruptAdaptor.port_b,pipeSmall.port_a);
  connect(pipeSmall.port_b,P_bound.ports[1]);

  // Case #2
  //connect(M_bound.ports[1],pipeSmall.port_b);
  //connect(abruptAdaptor.port_b,pipeSmall.port_a);
  //connect(abruptAdaptor.port_a,P_bound.ports[1]);

  annotation (uses(Modelica(version="3.2.1")));
end AbruptAdaptor_1Pipe;