Fix calculation of Reynolds number for non-circular pipes in Detailed…

…PipeFlow model (#1601) - pass crossArea A to Pipes.BaseClasses.WallFriction models, in addition to hydraulic diameter D - remove simplification A/D =?= pi/4*D from DetailedPipeFlow model - add Modelica.Fluid.Examples.NonCircularPipes git-svn-id: https://svn.modelica.org/projects/Modelica/trunk@8037 7ce873d0-865f-4ce7-a662-4bb36ea78beb
modelica · Jan 6, 2015 · 29a6741 · 29a6741
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diff --git a/Modelica/Fluid/Examples/NonCircularPipes.mo b/Modelica/Fluid/Examples/NonCircularPipes.mo
@@ -0,0 +1,69 @@
+within Modelica.Fluid.Examples;
+model NonCircularPipes "Comparing a circular with a non-circular pipe"
+  extends Modelica.Icons.Example;
+  replaceable package Medium = Modelica.Media.Water.StandardWater;
+  constant Real odim = 0.015;
+  constant Real idim = 0.005;
+  inner Modelica.Fluid.System system(energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial)
+                                     annotation(Placement(visible = true, transformation(origin = {-80, 80}, extent = {{-10, -10}, {10, 10}}, rotation = 0)));
+  Modelica.Fluid.Sources.Boundary_pT boundary(
+    redeclare package Medium = Medium,
+    nPorts = 2,
+    p = 10.0e5,
+    T = 293.15)
+    annotation(Placement(visible = true, transformation(origin = {-80, 0}, extent = {{-10, -10}, {10, 10}}, rotation = 0)));
+  Modelica.Fluid.Sources.MassFlowSource_T massflowsink1(redeclare package
+      Medium =                                                                     Medium, nPorts = 1, m_flow = -0.1, T = 293.15) annotation(Placement(visible = true, transformation(origin = {40, 40}, extent = {{10, -10}, {-10, 10}}, rotation = 0)));
+  Modelica.Fluid.Sources.MassFlowSource_T massflowsink2(redeclare package
+      Medium =                                                                     Medium, nPorts = 1, m_flow = -0.1, T = 293.15) annotation(Placement(visible = true, transformation(origin = {40, -40}, extent = {{10, -10}, {-10, 10}}, rotation = 0)));
+  Modelica.Fluid.Pipes.DynamicPipe circular_pipe(
+    redeclare package Medium = Medium,
+    length = 100, diameter = 0.01,
+    T_start = 293.15,
+    p_a_start = 10.0e5, p_b_start = 10.0e5)
+    annotation(Placement(visible = true, transformation(origin = {-20, 40}, extent = {{-10, -10}, {10, 10}}, rotation = 0)));
+  Modelica.Fluid.Pipes.DynamicPipe annulus_pipe(
+    redeclare package Medium = Medium,
+    length = 100,
+    crossArea = Modelica.Constants.pi * (odim ^ 2 - idim ^ 2) / 4,
+    perimeter = Modelica.Constants.pi * (odim + idim),
+    isCircular=false,
+    diameter=0,
+    p_a_start=1000000,
+    p_b_start=1000000,
+    T_start=293.15)
+    annotation(Placement(visible = true, transformation(origin = {-20, -40}, extent = {{-10, -10}, {10, 10}}, rotation = 0)));
+equation
+  connect(boundary.ports[1], circular_pipe.port_a) annotation(Line(points={{-70,2},
+          {-60,2},{-60,40},{-30,40}},                                                                                   color = {0, 127, 255}));
+  connect(boundary.ports[2], annulus_pipe.port_a) annotation(Line(points={{-70,-2},
+          {-60,-2},{-60,-40},{-30,-40}},                                                                                 color = {0, 127, 255}));
+  connect(circular_pipe.port_b, massflowsink1.ports[1]) annotation(Line(points = {{-10, 40}, {30, 40}}, color = {0, 127, 255}));
+  connect(annulus_pipe.port_b, massflowsink2.ports[1]) annotation(Line(points = {{-10, -40}, {30, -40}}, color = {0, 127, 255}));
+  annotation(experiment(StopTime=1),
+  Icon(coordinateSystem(extent = {{-100, -100}, {100, 100}}, preserveAspectRatio = true, initialScale = 0.1, grid = {2, 2})), Diagram(coordinateSystem(extent = {{-100, -100}, {100, 100}}, preserveAspectRatio = true, initialScale = 0.1, grid = {2, 2})),
+  Documentation(info="<html>
+<p>
+In this example two pipes are used to demonstrate the use of circular (default) and non-circular pipes,
+where the topmost pipe is circular with a length of 100 m and an inner diamter of 10 mm and the second pipe
+is a circular ring pipe with inner diameter of 5 mm and an outer diamter of 15 mm.
+</p>
+<p>
+Both pipes are connected to a pT source (water, 293.15 K, 10 bar) and a mass flow sink (0.1 kg/s inflow).
+</p>
+<p>
+Although the hydraulic diameter of both pipes are the same, the different cross sections lead to different
+velocities and by this different outlet pressures (7.324 bar for the circular pipe versus 9.231 bar for the
+circular ring pipe).
+</p>
+<p><img src=\"modelica://Modelica/Resources/Images/Fluid/Examples/NonCircularPipes.png\" border=\"1\"
+     alt=\"NonCircularPipes.png\"></p>
+</html>", revisions="<html>
+<ul>
+<li>
+January 6, 2014 by Alexander T&auml;schner:<br/>
+First implementation.
+</li>
+</ul>
+</html>"));
+end NonCircularPipes;
diff --git a/Modelica/Fluid/Examples/package.order b/Modelica/Fluid/Examples/package.order
@@ -6,6 +6,7 @@ ControlledTankSystem
 AST_BatchPlant
 IncompressibleFluidNetwork
 BranchingDynamicPipes
+NonCircularPipes
 HeatExchanger
 TraceSubstances
 InverseParameterization