提问人：Aleksandr Kozlenok 提问时间：6/1/2023 最后编辑：Aleksandr Kozlenok 更新时间：6/13/2023 访问量：80
如何反转 SweptVolume 块？
How to reverse the SweptVolume block?
问：
我正在尝试模拟一个简单的案例。一个 sweptVolume 连接到另一个 sweptVolume。Flange.b 到 flange.b 是这样：
当油室中的压力上升时，体积扩大，活塞向外移动。（到目前为止，一切都很好，很合乎逻辑）。
气室容积应该减小，压力应该上升（我们有一个压缩场景）。气室没有液压输出。它已关闭。
但是，在图上，我可以看到气室活塞正在向外移动，压力在降低，体积在扩大。
我认为，如果连接两个液压缸，第一个液压缸会膨胀，第二个液压缸会塌陷（这是您在 Matlab 中通常期望的）。
如何反转第二个 sweptVolume？
这是我的代码：
model Jack1
inner Modelica.Fluid.System system(energyDynamics = Modelica.Fluid.Types.Dynamics.FixedInitial) annotation(
Placement(visible = true, transformation(origin = {0, 56}, extent = {{60, -96}, {80, -76}}, rotation = 0)));
Modelica.Mechanics.Translational.Sources.Force force annotation(
Placement(visible = true, transformation(origin = {-30, 70}, extent = {{-10, -10}, {10, 10}}, rotation = 0)));
Modelica.Blocks.Sources.Ramp ramp(duration = 6, height = -250, startTime = 1) annotation(
Placement(visible = true, transformation(origin = {-70, 70}, extent = {{-10, -10}, {10, 10}}, rotation = 0)));
Modelica.Fluid.Machines.SweptVolume OilChamber(redeclare package Medium = Modelica.Media.Water.StandardWater, clearance = 0.00105, flange(s(start = 0.1)), nPorts = 1, pistonCrossArea = 0.0019625, portsData = {Modelica.Fluid.Vessels.BaseClasses.VesselPortsData(diameter = 0.014)}) annotation(
Placement(visible = true, transformation(origin = {0, 8}, extent = {{10, -10}, {-10, 10}}, rotation = 180)));
Modelica.Fluid.Machines.SweptVolume Jack(redeclare package Medium = Modelica.Media.Water.StandardWater, clearance = 0.00105, flange(s(start = 0.1)), nPorts = 1, pistonCrossArea = 0.0019625, portsData = {Modelica.Fluid.Vessels.BaseClasses.VesselPortsData(diameter = 0.01)}) annotation(
Placement(visible = true, transformation(origin = {0, 48}, extent = {{10, 10}, {-10, -10}}, rotation = -180)));
Modelica.Fluid.Machines.SweptVolume GasChamber(redeclare package Medium = Modelica.Media.IdealGases.SingleGases.N2, clearance = 0.00105, flange(s(start = 0.1)), nPorts = 0, pistonCrossArea = 0.0019625) annotation(
Placement(visible = true, transformation(origin = {0, -30}, extent = {{10, 10}, {-10, -10}}, rotation = 180)));
equation
connect(ramp.y, force.f) annotation(
Line(points = {{-59, 70}, {-43, 70}}, color = {0, 0, 127}));
connect(force.flange, Jack.flange) annotation(
Line(points = {{-20, 70}, {0, 70}, {0, 58}}, color = {0, 127, 0}));
connect(OilChamber.ports[1], Jack.ports[1]) annotation(
Line(points = {{0, 18}, {0, 38}}, color = {0, 127, 255}));
connect(OilChamber.flange, GasChamber.flange) annotation(
Line(points = {{0, -2}, {0, -20}}, color = {0, 127, 0}));
annotation(
uses(Modelica(version = "4.0.0")),
Diagram(coordinateSystem(extent = {{-100, -100}, {100, 100}})));
end Jack1;
答：
0赞
Hans Olsson
6/13/2023
#1
根本问题是 SweptVolume 应该有两个法兰（用于两侧），而不仅仅是一个。似乎可以通过一个适配器来切换法兰的方向来修复它，但我无法完全让它工作。
但是，这可能是一个开始，并且用于反转法兰方向：
model ReverseSign
parameter Real offset=1;
Modelica.Mechanics.Translational.Interfaces.Flange_b flange_b
annotation (Placement(transformation(extent={{90,28},{110,48}})));
Modelica.Mechanics.Translational.Interfaces.Flange_b flange_b1
annotation (Placement(transformation(extent={{90,-18},{110,4}})));
equation
flange_b.s=offset-flange_b1.s;
flange_b.f=-flange_b1.f;
annotation (
Icon(coordinateSystem(preserveAspectRatio=false)),
Diagram(coordinateSystem(preserveAspectRatio=false)),
uses(Modelica(version="4.0.0")));
end ReverseSign;
然后在更新的模型中使用它：
model Jack1
inner Modelica.Fluid.System system(energyDynamics=Modelica.Fluid.Types.Dynamics.DynamicFreeInitial)
annotation (Placement(visible=true, transformation(
origin={0,56},
extent={{60,-96},{80,-76}},
rotation=0)));
Modelica.Mechanics.Translational.Sources.Force force annotation (Placement(
visible=true, transformation(
origin={-30,70},
extent={{-10,-10},{10,10}},
rotation=0)));
Modelica.Blocks.Sources.Ramp ramp(
duration=6,
height=-250,
startTime=1) annotation (Placement(visible=true, transformation(
origin={-70,70},
extent={{-10,-10},{10,10}},
rotation=0)));
Modelica.Fluid.Machines.SweptVolume OilChamber(
redeclare package Medium = Modelica.Media.Water.StandardWater,
clearance=0.00105,
flange(s(start=0.1)),
nPorts=1,
pistonCrossArea=0.0019625,
portsData={Modelica.Fluid.Vessels.BaseClasses.VesselPortsData(diameter=0.014)})
annotation (Placement(visible=true, transformation(
origin={0,8},
extent={{10,-10},{-10,10}},
rotation=180)));
Modelica.Fluid.Machines.SweptVolume Jack(
redeclare package Medium = Modelica.Media.Water.StandardWater,
clearance=0.00105,
flange(s(start=0.1)),
nPorts=1,
pistonCrossArea=0.0019625,
portsData={Modelica.Fluid.Vessels.BaseClasses.VesselPortsData(diameter=0.01)})
annotation (Placement(visible=true, transformation(
origin={0,48},
extent={{10,10},{-10,-10}},
rotation=-180)));
Modelica.Fluid.Machines.SweptVolume GasChamber(
redeclare package Medium = Modelica.Media.IdealGases.SingleGases.N2,
clearance=0.00105,
flange(s(start=0.1)),
nPorts=0,
pistonCrossArea=0.0019625) annotation (Placement(visible=true,
transformation(
origin={0,-30},
extent={{10,10},{-10,-10}},
rotation=180)));
ReverseSign reverseSign(offset=0.2)
annotation (Placement(transformation(extent={{-44,-22},{-24,-2}})));
equation
connect(ramp.y, force.f)
annotation (Line(points={{-59,70},{-42,70}}, color={0,0,127}));
connect(force.flange, Jack.flange)
annotation (Line(points={{-20,70},{0,70},{0,58}}, color={0,127,0}));
connect(OilChamber.ports[1], Jack.ports[1])
annotation (Line(points={{0,18},{0,38}}, color={0,127,255}));
connect(reverseSign.flange_b, OilChamber.flange)
annotation (Line(points={{-24,-8.2},{0,-8.2},{0,-2}}, color={0,127,0}));
connect(reverseSign.flange_b1, GasChamber.flange)
annotation (Line(points={{-24,-12.7},{0,-12.7},{0,-20}}, color={0,127,0}));
annotation (uses(Modelica(version="4.0.0")), Diagram(coordinateSystem(extent={
{-100,-100},{100,100}})));
end Jack1;
但不幸的是，模拟在大约 8 秒后停止。可能存在符号错误或其他一些逻辑错误 - 但至少这是一个起点。
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