Learning Forum

[apr37]

Hello ANSYS,

I have a moderately complicated surface I would like to integrate over in the fields calculator. I am familiar with how to integrate an expression over a surface in the fields calculator, e.g.

Scl: Integrate(Surface(object), expression)

but the surface I would like to integrate over does not directly correspond to the surfaces of any objects in my model.I'll discuss a simplified example of what I mean:

Suppose I have a cylindrical cavity. I would like to integrate some quantity (such as the square of the magnetic field) over the surface of that cavity, but I would like to exclude the top base of the cylinder from the integral. I could achieve this by creating a non-model circular surface object which is only the top base of that cylinder, then in the fields calculator I could perform two integrals and take their difference.

Scl: Integrate(Surface(cylinder), expression) - Integrate(Surface(circle), expression)
or more accurately in the field calculator syntax,
Scl: -(Integrate(Surface(cylinder), expression), Integrate(Surface(circle), expression))

But for moderately more complicated geometries, this approach becomes cumbersome, such as if I would like to integrate over a surface which requires me to combine 5 or so surface integrals in the fields calculator.

Is there a way to either

a. create a non-model composite surface object, such as a cylinder with an open top

or

b. Define a composite geometry expression in the fields calculator so that I could say something like the following?

Scl: Integrate(Surface(cylinder) - Surface(circle), expression)
or more similar to fields calculator syntax,
Scl: Integrate(-(Surface(cylinder), Surface(circle)), expression))

Thanks,
Alex

[Charlotte Blair]

Hi Alex,

 

You can subtract surfaces on volumes by selecting the face of the object then 

Edit > Surface > Detach Faces

To add surfaces select both surfaces

Edit > Boolean >Unite

Regards,

Charlotte

[apr37]

I think this will fix my problem!

For future readers, it looks like a similar tool available to me, located in a similar spot, is

Edit>Surface>Create Object from Face

It seems the main difference between these two tools is the objects that are left over from the operation, other than the object you are trying to create.

Thanks for the tip, Charlotte!

-Alex