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6:08 AM

Hello Everyone! I hope you people are having a nice weekend.

I want to study heat transfer in a hollow sphere using FEM.

How can I build a hollow sphere as a region of study having length 10, inner radius 1 and outer radius 5?

Any suggestion please?
Thanks

6 hours later…

Kuba

11:45 AM

@MMM what is the length of a hollow sphere? p.s. RegionDifference[Ball[{0, 0, 0}, 5], Ball[]]?

zhk

12:03 PM

@Kuba 10

zhk

12:14 PM

@Kuba But I get an error when i try this RegionPlot[RegionDifference[Ball[{0, 0, 0}, 5], Ball[]]]

Kuba

@MMM I mean, that does it mean the lenght of a spehere?

@MMM

Show[Region@RegionDifference[Ball[{0, 0, 0}, 5], Ball[]],
 ClipPlanes -> {{1, 0, 0, 0}}]

zhk

@Kuba the sphere 10 m/in/ft long.

@Kuba Still get an error

Kuba

12:29 PM

@MMM sphere is determined by radius and center's position. Define lenght

Code above works well in 11.1. What error did you get and in which version?

zhk

12:43 PM

@Kuba The length is 10, the inner radius is 1 and the outer is 5

@Kuba Show::gtype: Region is not a type of graphics.

zhk

1:00 PM

@Kuba AM I not making any sense?

Kuba

@zhk not for me, sorry. Don't know what does it mean 'the length of a sphere". I have to go now.

zhk

@Kuba OK we will discuss next time. Thx

@Kuba Sorry dear my bad I was thinking about cylinder and talking about sphere

@Kuba my bad really sorry

halirutan

@Szabolcs Can you tell me what distribution and version you are using?

3 hours later…

zhk

4:24 PM

@Kuba Hello there!

The issue remain unresolved

Show[Region@RegionDifference[Ball[{0, 0, 0}, 5], Ball[]]]
gives me
Show::gtype: Region is not a type of graphics.

RegionPlot[RegionDifference[Ball[{0, 0, 0}, 5], Ball[]]]
gives me
RegionPlot::nnregion: RegionDifference[Ball[{0,0,0},5],Ball[{0,0,0}]] cannot be automatically discretized.

"11.0.1 for Microsoft Windows (32-bit) (September 21, 2016)"

2 hours later…

Kuba

6:27 PM

@zhk yep, Cylidner makes sense :) I don't do so much with regions so I don't know how were they updated recently and what should work in which version.

@zhk what about DiscretizeRegion@RegionDifference[Ball[{0, 0, 0}, 5], Ball[]]?