如何使用Modelica Standard库的SimpleGenerericrifice在管道中施加压力损失？

Question

我想建模一个液压网络，在其中使用moderica.fluid.fittings.simpleglegleglecleericorifice作为密封件，以便我可以施加管道的压力损失。使用文档中的公式，我可以计算孔口的Zeta系数。

这是一个简化的例子，在这里我试图在管道内施加50 bar的压力损失。因为端口的压力应相等，所以我认为它应该起作用：

但是，我的管道和孔口中没有任何压力损失。

有人知道如何做这项工作吗？

这是示例的代码

model Joints_HD

replaceable package Medium=Modelica.Media.Water.StandardWater constrainedby
    Modelica.Media.Interfaces.PartialMedium;

  Modelica.Fluid.Pipes.StaticPipe pipe(redeclare package Medium = Medium,diameter = 0.15, length = 1)  annotation(
    Placement(visible = true, transformation(origin = {-38, 10}, extent = {{-10, -10}, {10, 10}}, rotation = 0)));
  
  inner Modelica.Fluid.System system annotation(
    Placement(visible = true, transformation(origin = {-70, 42}, extent = {{-10, -10}, {10, 10}}, rotation = 0)));
  
  Modelica.Fluid.Sources.Boundary_pT boundary(redeclare package Medium = Medium,T = 328.15, p = 157e5, nPorts = 1)  annotation(
    Placement(visible = true, transformation(origin = {-66, 10}, extent = {{-10, -10}, {10, 10}}, rotation = 0)));
  Modelica.Fluid.Sources.MassFlowSource_T boundary1(redeclare package Medium = Medium,T = 328.15, m_flow = -0.17, nPorts = 1)  annotation(
    Placement(visible = true, transformation(origin = {72, 10}, extent = {{10, -10}, {-10, 10}}, rotation = 0)));
  
  Modelica.Fluid.Pipes.StaticPipe pipe2(redeclare package Medium = Medium,diameter = 0.15, length = 1)  annotation(
    Placement(visible = true, transformation(origin = {44, 10}, extent = {{-10, -10}, {10, 10}}, rotation = 0)));
  
  Modelica.Fluid.Fittings.SimpleGenericOrifice orifice(redeclare package Medium = Medium,diameter = 0.15, dp_nominal = 5e+06, m_flow_nominal = 2.34e-9, use_zeta = false)  annotation(
    Placement(visible = true, transformation(origin = {2, 10}, extent = {{-10, -10}, {10, 10}}, rotation = 0)));
  
  Modelica.Fluid.Pipes.StaticPipe pipe1(redeclare package Medium = Medium, diameter = 0.15, length = 1)  annotation(
    Placement(visible = true, transformation(origin = {2, -18}, extent = {{-10, -10}, {10, 10}}, rotation = 0)));

equation
  
  connect(boundary.ports[1], pipe.port_a) annotation(
    Line(points = {{-56, 10}, {-48, 10}}, color = {0, 127, 255}));
  connect(pipe.port_b, orifice.port_a) annotation(
    Line(points = {{-28, 10}, {-8, 10}}, color = {0, 127, 255}));
  connect(pipe2.port_b, boundary1.ports[1]) annotation(
    Line(points = {{54, 10}, {62, 10}}, color = {0, 127, 255}));
  connect(orifice.port_b, pipe2.port_a) annotation(
    Line(points = {{12, 10}, {34, 10}}, color = {0, 127, 255}));
  connect(pipe.port_b, pipe1.port_a) annotation(
    Line(points = {{-28, 10}, {-20, 10}, {-20, -18}, {-8, -18}}, color = {0, 127, 255}));
  connect(pipe1.port_b, pipe2.port_a) annotation(
    Line(points = {{12, -18}, {26, -18}, {26, 10}, {34, 10}}, color = {0, 127, 255}));
  annotation(
    uses(Modelica(version = "3.2.3")));

end Joints_HD;

最好的问候， Maxime

Answer 1

Pipe1具有“错误”维度（直径，长度，粗糙度等），因为它仅产生很小的压力下降。

要验证该模型的其余部分还可以 - 并且您可以在pipe1 boundard> boundard> boundard> boundard> boundare1 （0.17 kg/s）上的压力下降50 bar（0.17 kg/s） - 临时更改pipe1.flowmodel suminalTurbulentPipeFlow带有m_flow_nominal = 0.17和dp_nominal = dp_nominal = 50 bar。

随后，将流模型切换回默认（详细）模型，然后调整管道几何形状。

顺便说一句，即使不使用它，您也应该为orifice.zeta提供一个值。