自定义Modelica介质接入MSL阀门初始化时出现负压高温问题

我基于MSL库的PartialMedium构建了燃料输送系统的自定义介质，已通过介质示例工具及3000bar压力测试。但在流系统中加入阀门后，介质初始化时出现压力负值（-2.3977e+08 Pa）、温度异常升高（192190 K），触发断言错误。

已完成的测试 #

• 使用StandardWater介质时，含阀门的简单测试模型运行正常；
• 尝试多种额定质量流量和压差参数；
• 不含阀门的简单流模型运行符合预期；
• 切换比热容符号；
• 设置阀门为常开状态。

后续排查结果 #

替换为Modelica.Fluid.Pipes.StaticPipe模型可正常运行，但我的目标是构建燃油喷射系统，必须用DynamicPipe精准捕捉压力变化，调整动态管道结构无效。进一步测试确认问题源于介质定义，改用PartialLinearFluid扩展介质后仿真可启动但速度极慢。

附相关Modelica代码 #

package SO
       
package MyMedia_v5 "Template for media models"
  extends Modelica.Media.Interfaces.PartialMedium(final mediumName = "MyLiquid", final substanceNames = {mediumName}, final singleState = false, final reducedX = true, final fixedX = true, Temperature(min = 273, max = 373, start = 298), p_default = 1e5, reference_p = 1e5, reference_T = 298, reference_X = {1}, AbsolutePressure(min = 1e-6, max = 3e8, start = 1e5), ThermoStates = Modelica.Media.Interfaces.Choices.IndependentVariables.pT);
  // Provide medium constants here
  constant SpecificHeatCapacity cp_const = 1250 "Constant specific heat capacity at constant pressure";
  constant SpecificHeatCapacity cv_const = 1100 "Constant specific heat capacity at constant volume";
  constant Temperature T0 = reference_T "Zero enthalpy temperature";
  constant MolarMass MM_const = 12 "Molar mass";
  constant DynamicViscosity eta_const = 0.05 "Constant dynamic viscosity";
  constant ThermalConductivity lambda_const = 0.1 "Constant thermal conductivity";
  constant VelocityOfSound a_const = 1300 "Constant velocity of sound";

  redeclare model extends BaseProperties(final standardOrderComponents = true) "Base properties of medium"
    equation
      d = density(state);
      h = specificEnthalpy(state);
      u = h - p/d;
      MM = 0.025;
      R_s = 0;
      state.p = p;
      state.T = T;
  end BaseProperties;

  redeclare replaceable record ThermodynamicState "A selection of variables that uniquely defines the thermodynamic state"
    extends Modelica.Icons.Record;
    AbsolutePressure p "Absolute pressure of medium";
    Temperature T "Temperature of medium";
    annotation(
      Documentation(info = "<html>  
  </html>"));
  end ThermodynamicState;

  redeclare function extends setState_pTX "Return thermodynamic state as function of p, T and composition X or Xi"
      extends Modelica.Icons.Function;

    algorithm
      state := ThermodynamicState(p = p, T = T);
    annotation(
      Inline = true);
  end setState_pTX;

  redeclare function setState_phX "Return thermodynamic state from p, h, and X or Xi"
    extends Modelica.Icons.Function;
    input AbsolutePressure p "Pressure";
    input SpecificEnthalpy h "Specific enthalpy";
    input MassFraction X[:] = reference_X "Mass fractions";
    output ThermodynamicState state "Thermodynamic state record";
  algorithm
    state := ThermodynamicState(p = p, T = T0 + h/cp_const);
  end setState_phX;

  redeclare function setState_dTX "Return thermodynamic state from p, h, and X or Xi"
    extends Modelica.Icons.Function;
    input Density d "Density";
    input SpecificEnthalpy h "Specific enthalpy";
    input MassFraction X[:] = reference_X "Mass fractions";
    output ThermodynamicState state "Thermodynamic state record";
  protected
    constant Real d_init = 892.2;
    constant Real p_init = 200;
    constant Real a1 = 4.0654;
    constant Real a2 = 10130;
    Real p_bar = state.p*1e-5;
  algorithm
    state := ThermodynamicState(p = 1e5*(Modelica.Math.log(d/d_init)*a2 + p_init)/(1 - Modelica.Math.log(d/d_init)), T = T);
  end setState_dTX;

  redeclare function extends specificEnthalpy "Return specific enthalpy"
    algorithm
      h := cp_const*(state.T - T0);
  end specificEnthalpy;

  redeclare function extends pressure "Return the Pressure"
    algorithm
      p := state.p;
  end pressure;

  redeclare function extends specificHeatCapacityCp "Return specific heat capacity at constant pressure"
    algorithm
      cp := cp_const;
  end specificHeatCapacityCp;

  redeclare function extends specificHeatCapacityCv "Return specific heat capacity at constant volume"
    algorithm
      cv := cv_const;
  end specificHeatCapacityCv;

  redeclare function extends density "Return the density"
      input ThermodynamicState state;
      output Density d;

    protected
      constant Real d_init = 892.2;
      constant Real p_init = 200;
      constant Real a1 = 4.0654;
      constant Real a2 = 10130;
      Real p_bar = state.p*1e-5;

    algorithm
      d := d_init*Modelica.Math.exp((p_bar - p_init)/(a1*p_bar + a2));
    annotation(
      smoothOrder = 1,
      Inline = true);
  end density;

  redeclare function extends temperature "Return temperature"
      input ThermodynamicState state "Thermodynamic state record";
      output Temperature T "Temperature";

    algorithm
      T := state.T;
  end temperature;

  redeclare function extends dynamicViscosity "Return dynamic viscosity"
    algorithm
      eta := eta_const;
    annotation(
      Documentation(info = "<html>  
  </html>"));
  end dynamicViscosity;

  redeclare function extends thermalConductivity "Return thermal conductivity"
    algorithm
      lambda := 0.1;
    annotation(
      Documentation(info = "<html>  
  </html>"));
  end thermalConductivity;

  redeclare function extends isentropicExponent "Return isentropic exponent"
      extends Modelica.Icons.Function;

    algorithm
      gamma := 1.16;
    annotation(
      Documentation(info = "<html>  
  </html>"));
  end isentropicExponent;

  redeclare function extends velocityOfSound "Return velocity of sound"
      extends Modelica.Icons.Function;

    algorithm
      a := 1100;
    annotation(
      Documentation(info = "<html>  
  </html>"));
  end velocityOfSound;
end MyMedia_v5;
    
model TestOfMyMedium5
  replaceable package Medium = MyMedia_v4 "Medium in the component" annotation(
      choicesAllMatching = true);
  Modelica.Fluid.Sources.Boundary_pT boundary(nPorts = 1, redeclare package Medium = Medium, p = 1e5) annotation(
    Placement(transformation(origin = {90, 0}, extent = {{-10, -10}, {10, 10}}, rotation = 180)));
  Modelica.Fluid.Pipes.DynamicPipe pipe(redeclare package Medium = Medium, length = 0.1, diameter = 0.1) annotation(
    Placement(transformation(origin = {-50, 0}, extent = {{-10, -10}, {10, 10}})));
  Modelica.Blocks.Sources.Ramp ramp(duration = 0.8, startTime = 0.1, height = 0.1, offset = 0.9) annotation(
    Placement(transformation(origin = {-36, 42}, extent = {{-10, -10}, {10, 10}})));
  Modelica.Fluid.Pipes.DynamicPipe pipe1(redeclare package Medium = Medium, diameter = 0.1, length = 0.1) annotation(
    Placement(transformation(origin = {42, 0}, extent = {{-10, -10}, {10, 10}})));
  inner Modelica.Fluid.System system(use_eps_Re = true) annotation(
    Placement(transformation(origin = {-86, 86}, extent = {{-10, -10}, {10, 10}})));
  Modelica.Fluid.Valves.ValveLinear valveLinear(redeclare package Medium = Medium, dp_nominal = 1e4, m_flow_nominal = 1) annotation(
    Placement(transformation(extent = {{-10, -10}, {10, 10}})));
  Modelica.Fluid.Sources.Boundary_pT boundaryIn(redeclare package Medium = Medium, nPorts = 1, p = 5e5) annotation(
    Placement(transformation(origin = {-90, 0}, extent = {{-10, -10}, {10, 10}})));
  Modelica.Blocks.Sources.Constant const(k = 1) annotation(
    Placement(transformation(origin = {-18, 90}, extent = {{-10, -10}, {10, 10}})));
equation
  connect(pipe1.port_b, boundary.ports[1]) annotation(
    Line(points = {{52, 0}, {80, 0}}, color = {0, 127, 255}));
  connect(pipe.port_b, valveLinear.port_a) annotation(
    Line(points = {{-40, 0}, {-10, 0}}, color = {0, 127, 255}, thickness = 0.5));
  connect(valveLinear.port_b, pipe1.port_a) annotation(
    Line(points = {{10, 0}, {32, 0}}, color = {0, 127, 255}));
  connect(boundaryIn.ports[1], pipe.port_a) annotation(
    Line(points = {{-80, 0}, {-60, 0}}, color = {0, 127, 255}, thickness = 0.5));
  connect(ramp.y, valveLinear.opening) annotation(
    Line(points = {{-25, 42}, {0, 42}, {0, 8}}, color = {0, 0, 127}));
end TestOfMyMedium5;
end SO;

内容的提问来源于stack exchange，提问作者quaternio