MSL4.x中自定义修改DynamicPipe模型的编译错误求解

问题背景 #

因特定需求需修改Modelica.Fluid.DynamicPipe模型（无法用FlowModel替代），MSL3.x可直接修改本地库副本，但MSL4.x无法修改官方库，只能自建模型副本。当前自定义模型代码如下：

model w2DynamicPipe1 "Dynamic pipe model with storage of mass and energy"
  import Modelica.Fluid.Types.ModelStructure;
  // extending PartialStraightPipe
  extends Modelica.Fluid.Pipes.BaseClasses.PartialStraightPipe(final port_a_exposesState = modelStructure == ModelStructure.av_b or modelStructure == ModelStructure.av_vb, final port_b_exposesState = modelStructure == ModelStructure.a_vb or modelStructure == ModelStructure.av_vb);
  // extending PartialTwoPortFlow
  extends Modelica.Fluid.Pipes.BaseClasses.PartialTwoPortFlow (final lengths = fill(length / n, n), final crossAreas = fill(crossArea, n), final dimensions = fill(4 * crossArea / perimeter, n), final roughnesses = fill(roughness, n), final dheights = height_ab * dxs);
  // Wall heat transfer
end w2DynamicPipe1;

编译验证返回错误信息：

[86] 12:23 Validation of w2DynamicPipe1 finished 
Notification: Modelica.Fluid.Interfaces.PartialTwoPort [3:5-3:5] Missing inner. Outer declaration system is missing a corresponding inner declaration. An inner declaration will be added using the outer declaration.
Error: Modelica.Fluid.Interfaces.PartialDistributedVolume [34:5-34:5] Invalid instantiation. Modelica.Media.Interfaces.PartialMedium.BaseProperties is partial.
Validation of model w2_Models.w2pipes.w2DynamicPipe1 completed with 1 error.

解决方案 #

1. 修复PartialMedium.BaseProperties is partial错误 #

这个错误源于底层Partial类依赖具体介质模型，而非抽象的PartialMedium。有两种解决方式：

• 方式1：显式声明介质并传递给继承类
  在自定义模型中添加介质参数，并确保继承的Partial类使用该介质：

  model w2DynamicPipe1 "Dynamic pipe model with storage of mass and energy"
    import Modelica.Fluid.Types.ModelStructure;
    // 声明具体介质（可替换为你需要的介质）
    replaceable package Medium = Modelica.Media.Water.StandardWater "Medium model" annotation(
      choicesAllMatching = true);
    
    // 传递介质给PartialStraightPipe
    extends Modelica.Fluid.Pipes.BaseClasses.PartialStraightPipe(
      final port_a_exposesState = modelStructure == ModelStructure.av_b or modelStructure == ModelStructure.av_vb, 
      final port_b_exposesState = modelStructure == ModelStructure.a_vb or modelStructure == ModelStructure.av_vb,
      redeclare package Medium = Medium);
    
    // 传递介质给PartialTwoPortFlow
    extends Modelica.Fluid.Pipes.BaseClasses.PartialTwoPortFlow (
      final lengths = fill(length / n, n), 
      final crossAreas = fill(crossArea, n), 
      final dimensions = fill(4 * crossArea / perimeter, n), 
      final roughnesses = fill(roughness, n), 
      final dheights = height_ab * dxs,
      redeclare package Medium = Medium);
    // Wall heat transfer
  end w2DynamicPipe1;
  

• 方式2：直接继承原DynamicPipe再修改
  复用原模型的介质传递逻辑，避免手动处理底层依赖：

  model w2DynamicPipe1 "Dynamic pipe model with storage of mass and energy"
    import Modelica.Fluid.Types.ModelStructure;
    // 继承原DynamicPipe并覆盖需要修改的参数
    extends Modelica.Fluid.DynamicPipe(
      final port_a_exposesState = modelStructure == ModelStructure.av_b or modelStructure == ModelStructure.av_vb, 
      final port_b_exposesState = modelStructure == ModelStructure.a_vb or modelStructure == ModelStructure.av_vb,
      final lengths = fill(length / n, n), 
      final crossAreas = fill(crossArea, n), 
      final dimensions = fill(4 * crossArea / perimeter, n), 
      final roughnesses = fill(roughness, n), 
      final dheights = height_ab * dxs);
    // 在这里添加自定义修改（比如替换FlowModels/HeatTransfer）
  end w2DynamicPipe1;
  

2. 处理Missing inner/outer通知 #

这个通知是因为Fluid模型需要顶层的inner System声明：

• 在使用w2DynamicPipe1的顶层模型中添加：

  inner Modelica.Fluid.System system;
  

• 或者在w2DynamicPipe1中显式声明：

  outer Modelica.Fluid.System system;
  

  推荐前者，确保所有子模型共享同一个System实例。

后续替换自定义FlowModels/HeatTransfer指导 #

• 替换FlowModels：找到PartialTwoPortFlow中定义的replaceable model FlowModel参数，在w2DynamicPipe1中用redeclare替换为自定义模型，确保自定义模型与原FlowModel的接口一致（输入输出变量、参数匹配）。
• 替换HeatTransfer：同理，找到PartialStraightPipe或相关类中的HeatTransfer模型，用redeclare替换，保证热传递逻辑的接口兼容（比如温度、热流量的传递方式）。

内容的提问来源于stack exchange，提问作者Chris B