added hydraulic example

Author: Brad Carman

README.md

@@ -51,7 +51,7 @@ end
 Then we can visualize the system using `ODESystemDesign()` and the `view()` functions
 
 ```julia
-path = "./design" # folder where visualization info is saved and retrieved
+path = joinpath(@__DIR__, "design") # folder where visualization info is saved and retrieved
 design = ODESystemDesign(sys, path);
 ModelingToolkitDesigner.view(design)
 ```

examples/design/Main/System.jl

@@ -0,0 +1,4 @@
+connect(stp.output, src.input)
+connect(src.port, res.port_a)
+connect(vol.port, res.port_b)
+connect(src.port, fluid)

examples/design/Main/System.toml

@@ -0,0 +1,22 @@
+[fluid]
+x = 0.38
+y = -0.01
+
+[res]
+port_a = "W"
+x = 0.47
+y = 0.09
+
+[src]
+input = "W"
+x = 0.3
+y = 0.09
+
+[stp]
+x = 0.12
+y = 0.09
+
+[vol]
+port = "W"
+x = 0.64
+y = 0.09

examples/hydraulic.jl

@@ -0,0 +1,38 @@
+using ModelingToolkit
+using ModelingToolkitDesigner
+
+import ModelingToolkitStandardLibrary.Hydraulic.IsothermalCompressible as IC
+import ModelingToolkitStandardLibrary.Blocks as B
+
+
+@parameters t
+
+@component function System(; name)
+
+    pars = []
+
+    systems = @named begin
+        fluid = IC.HydraulicFluid(; density = 876, bulk_modulus = 1.2e9, viscosity = 0.034)
+
+        stp = B.Step(; height = 10e5, start_time = 0.005)
+        src = IC.InputSource(; p_int = 0)
+        vol = IC.FixedVolume(; p_int = 0, vol = 10.0)
+        res = IC.Pipe(5; p_int = 0, area = 0.01, length = 500.0)
+    end
+
+    eqs = [
+        connect(stp.output, src.input)
+        connect(src.port, res.port_a)
+        connect(vol.port, res.port_b)
+        connect(src.port, fluid)
+    ]
+
+
+    ODESystem(eqs, t, [], pars; name, systems)
+end
+
+@named sys = System()
+
+path = joinpath(@__DIR__, "design") # folder where visualization info is saved and retrieved
+design = ODESystemDesign(sys, path);
+ModelingToolkitDesigner.view(design)