SimScale CAE Forum

Error in meshing


#1

hi everyone ,
i am trying to simulated vane pump in multi-phase simulation type . but there is some error in meshing .
so, please help me to solve this issue.
project link
https://www.simscale.com/workbench/?pid=6332600146032922498&mi=spec%3A027f643f-1418-4e3a-bd63-f79c26915328%2Cservice%3AMESHING%2Cstrategy%3A2&sh=1


#2

Hi Rohit!

Make sure that your geometry is watertight. It looks like are still two open inlets/outlets. Fix the geometry and re-upload the model - if you still have problems I will jump back in and help you out!

Best,

Jousef


#3

still face same problem in meshing.


project link

https://www.simscale.com/workbench/?pid=3746181991004742941&mi=spec%3Af11371d2-d10c-48c5-9e03-b70b0a7f66a1%2Cservice%3AMESHING%2Cstrategy%3A2&sh=1


#4

Hi Rohit,

the issue is that either the outside or inside of the geometry will be maintained as the material point cannot see a difference in this case. Can you give more background information on what the setup will look like? We can create an optimized model accordingly. Right now there are also overlapping surfaces inside of your model which is not recommended in your case. Tagging @Get_Barried here for additional input.

Cheers,

Jousef


#5

hi sir
i think there is no overlapping section in this geometry . i make this model in solid works and check the intersection also and there is no intersection are detected.
for simulation setup:
simulation type - multi phase
inlet pressure -7 bar
inlet velocity - 11.77 m/s
outlet pressure - 6.8 bar
thank you,

Rohit


#6

Hi @ROHIT_SR,

Your issue seems to lie at the inlet outlet. This is because your geometry has “two” surfaces and this type of geometry while applicable in real life as objects do have a cover or thickness is not easily workable for CFD meshing. My suggestion now is to just tackle the problematic area since other areas “seemed” to mesh relatively well with no illegal cells. Remove the outer wall and proceed to remesh as show below.

Cheers.

Regards,
Barry


#7

hi sir,
i dont understand what you are trying to say.
i make another cad model which have separated inlet and outlet pipe part and then mate it.
this part are simulated and again there is problem in meshing.
project link

https://www.simscale.com/workbench/?pid=7616141584232596560&mi=spec%3A9f277d53-4305-4260-b2d1-a70861187e2b%2Cservice%3ASIMULATION%2Cstrategy%3A1

thank you,
rohit


#8

Hi again Rohit (cool that you’re so active by the way :wink: )!

What Barry tries to say is that no matter where the so called material point is it will always delete either the one or the other region of your model because the mesher assumes you are doing an internal flow analysis and will get rid of unnecessary irrelevant regions. Simple example:

  • If you have a pipe and the material point is inside of the pipe \rightarrow internal flow simulation

  • If you have the same pipe but with the material point being outside \rightarrow external flow simulation (which might not make much sense, depending on your application)


So the easiest and most convenient way is to create a model that consists of one “layer” - have a look at other multiphase flow simulations and you will see how the models have been built.

Cheers,

Jousef


#9

hi sir,
thank you for your detail explanation of this topic. finally i understand and lean the NEW thing in simulation world.
this problem are happen only for multi-phase type of simulation?
if i will simulated same object in different simulation type( incompressible), then can i will face same problem ?
thank you,
ROHIT


#10

Hi @ROHIT_SR,

No, this applies to meshes which applies to all simulations that make use of internal/external flow using SnappyHexMesh as its meshing algorithm.

Cheers.

Regards,
Barry