## 3D Design

#### Geometry scaling

• rumth
Subscriber

Hi,

I have a domain in large scale (18.5 m height and 10 m diameter) but my computational system (computer) is not updated enough to run the simulation. Can I use "Scale" to reduce the full scale domain to run the simulation?

Ansys Employee

yes, you can use scale to reduce domain.

you can reduce it in design modeler or spaceclaim.

if you already of mesh then you can also change the scale it in fluent using setting up domain - mesh - scale.

if this helps you please mark this as 'is solution' to help others on forum.

• peteroznewman
Subscriber

Hi Raju,

The physical size of the domain isn't the determining factor in whether your computer has enough resources to solve a model on that domain. A domain of 18.5m x 10m doesn't take any more computational resources to solve than a domain of 18.5mm x 10mm.

It's the number of nodes and elements it takes to fill the domain. If your computer can't handle that, or if the ANSYS Student license limits prevents the solver from running, then you need to reduce the number of nodes and elements. There are a few ways to do that.

1) Use symmetry.  Is there any plane of symmetry in your model?  Use that to cut the geometry in half, and that will also cut the nodes and elements about in half.  There may be two or three planes of symmetry.

2) Use Hex elements instead of Tet elements.  It takes about twice as many tet elements to fill a volume than hex elements for the same element size.

3) Use a coarse mesh in the large volume that has a low gradient in the solution quantity, and apply mesh controls to have a fine mesh in the small volume of high gradient.

Please post a picture to explain what you are trying to model.

Regards,
Peter

• rumth
Subscriber

Hi Peter,

Yes, meshing is the matter with computation resources.

Here is my 3d domain. I didn't mesh yet. What should I do to transparent the geometry to see inside of the geometry?

• Rob
Ansys Employee

In Meshing you can select the body (solid in this example) & then set transparency; 0.5 is a good value. For several bodies pick them all at the body level.

• rumth
Subscriber

Hi,

How can I take a cross section of a 3D cylinder?

Raju.

Ansys Employee

i assume you want to create a 2d surface at cross section.

create a plane at cross section position.

use Create - Slice option to split geometry with plane created.

copy the required surface at cross section using Concept - Surface from face.

• rumth
Subscriber

Hi,

I want to draw a circle with centre (2,3) using the sketching tool. How to draw it? I am drawing a circle with specific radius but cann't position the center to my expected point.

Is it possible to modify (change the center) a circle after sketch?

Raju.

Ansys Employee

yes, you can change it.

please use 'dimension' tab in sketch mode.

please give vertical and horizontal dimension.

please select center of circle, press ctrl key and select x axis or y axis and give dimension.

if this helps, please mark this as 'is solution' to help others on forum.