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Hi

check your geometry construction doc. There are functions to generate volumes from closed surface objects, even "caps" to close an open surface. Just as you have split operations to decompose a volume into surfaces, or a surface into lines ...

Important: when you "finish" the geoemtry last node, the geometrical OBJECTS (volumes, surfaces lines and points) are analysed and transformed into FEM ELEMENTS (domains, boundaries edgs and points) the latter are unique, identified (=numbered per category) ad you apply the physics to these elements (not to the mesh in COMSOL) meshing is the last discretisation of the elements. During this "geomanalyze" your objects might be split or decomposed (in NION mode) or might make overlapping elements (in assembly mode) the latter assembly in COMSOl has nothing to do with a traditional CAD part assembly.

Have fun COMSOLing

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Good luck
Ivar

I couldn't figure out the solution yet. In case I make a drawing in 2D plane using curve or line segments and finish it by ending the last point to the start point. After that I could revolve it around to make it a surface in 3D. But I believe it become just a surface. Multiphysics has functions like "convert to solid". But is that the way to make the object volume in this case ? I cannot extrude the 2D drawing to make it volume. Neither I could make it become a volume by revolving and using the function "convert to solid". Or by first converting to solid and then revolving. The result may looks like much the same as any of the complete 3D volumes in Multiphysics like a cone or a sphere, but I cannot use it in the boolean operation "Compose" which demands inputs be domains and solid ones. Any idea in which Multiphysics document and approximately on which page I could find the answer ?

It looks like it's possible to draw closed areas using "Bezier polygon" function. If "solid" is selected the drawing appears as a gray solid area. Revolving this most likely results a volume. But I'm drawing curves using both functions "Parametric Curve" and "Bezier Polygon". The enclosed area does not turn gray and the revolved object does not become a volume.
Could that mean I cannot use "Parametric Curve" to create solid 3D volume object in Multiphysics ?

Hi

if you draw a closed "loop" with one or several lines, you can "convert" it to a surface or a solid (3D), check the "Geometry right click Conversions"

by default a Besier polyline is a closed surface in 2D

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Good luck
Ivar

Hellow,

I have a similar problem. I wouldlike to transform a 4-pointed hypocicloid designed through the parametric curves into a solid surface. Can somebody help me? I'm new to comsol...

Thanks in advance!

Hello,

I think i figured the problem. The Curve you want to convert into a solid needs to be closed or at least enclose an area. Only then you can use the "Convert into solid" function.
Neither can you select three points and convert them into a curve. They just vanish.

But that might lead to problems when you are working with parametric curves, or tangents, where you don't know the exact positions of the end points but you would like to have them as an edge of your solid.