Meshing_Advice_

Coreform Cubit Meshing
#1

Hi,
I have a single volume model as below. Ideally, I would like to use HEX element wherever possible but I wish to have WEDGE elements in RED regions. Is it possible to have such a mesh combination within a single volume ? Or do I need to have separate volumes in the RED region to discretize it separately ? Please advice.

image
image1278×694 61.3 KB

Best regards,
Aakash

#2

image
image1243×615 79.9 KB

Try clicking the “Allow 1 Triangle” in the mapped mesh panel. This invokes the trimap meshing algorithm and actually allows more than one triangle in this case. Sweeping the mesh with a triangle will create the wedge elements.

I modified your STEP file to recreate the sharp edges with the remove surface command.

reset
import step “~/Downloads/model.STEP” heal
remove surface 3 extend
remove surface 1 extend
surface 5 scheme trimap
imprint all
merge all
mesh surface 5
mesh Volume 1
draw wedge all

#3

Thank you very much for the amazing description!

#4

Here is now a similar case, but just a single volume (.STEP attached). I can mesh this by adopting your above strategy for a 90deg sector and then reflecting it to form a tube. However, Is it possible to mesh it as a whole so as to have wedge elements at the ends of the tube and hex at the remaining region ?

image
image958×613 34.3 KB

model_360.STEP (27.0 KB)

Many thanks

Regards,
Aakash

#5

Hi,
As a follow up query regrading previous doubt, below code creates a meshed model as shown in the attached image:

create vertex location 1.35 0 10
create vertex location 1.35 0 -10
create vertex location 1.55 0 10
create vertex location 1.55 0 -10
create vertex location 1.8 0 10
create vertex location 1.8 0 -10
create vertex location 2.1 0 10
create vertex location 2.1 0 -10
create vertex location 1.35 0 4
create vertex location 1.35 0 -4
create vertex location 0.95 0 0

create surface vertex 1 3 4 2
create surface vertex 3 4 6 5
create surface vertex 6 5 7 8

create curve arc three vertex 9 11 10
create curve vertex 9 10

create surface curve 13 14

sweep surface 4 zaxis angle 180 keep
sweep surface 1 zaxis angle 180 keep
sweep surface 2 zaxis angle 180 keep
sweep surface 3 zaxis angle 180 keep

imprint all
merge all

surface 4 scheme trimap
mesh surface 4
mesh volume all

image
image980×616 22.9 KB

As it can be seen, the overall mesh quality great, however, inside the RED regions, the mesh slightly deviates from radial direction. Is it possible to have an absolute radial mesh throughout this setup ?

Many thanks in advance!

With kind regards,
Aakash

#6

Use a planar webcut through the entire model at the plane defined between the blue and gray volumes to enforce the radial mesh at that location.

#7

You must have surfaces, not curves, to define a swept volume. You would need to cut the volume into quarters at least. I would recommend a process like:

webcut the volume into quarters
imprint and merge
set the cross section surfaces to scheme trimap
mesh volume all

Karl

#8

Thank you so much for your advice. I shall work it out :slight_smile:

Regards,
Aakash