Hexa meshing of impeller and diffuser assembly
 

Hi,
I do CFD analysis of pumps basically centrifugal pumps. while meshing I use ICEM Tetra meshing,
I want to do hexa meshing for the same pump and want to check my result,
though we know, hexa meshing give accurate results, but at the same time it is very difficult to do.

I will be very thankful to you, if you share your experience and help me to sort out my problem.

I have ProE model of pump assembly, I want to learn blocking technology (as it is very difficult talk and compulsory for hexa meshing) for the pump.

Thanks in advance.

The best advice I can give on hexa blocking is to practise practise practise. I spent a long number of months learning how it worked and what to do on very simple geometries before applying the skills to more complex works.

I have had a go at creating a blocking structure on a fan blade and found it quite testing. I had a number of problems, mostly relating to cell quality and skewness...

in particular I found i could get a very good grid modelling the surface of the fan blade, and the boundary layer region, but it lead to poor quality cells in the domain around the fan. when i modified the blocks, the opposite happened.

it could well have been my blocking structure - so again, the best advice is practise and perserverance

good luck!

Thanks
 

Thanks for the reply.

Would you please send me some good and easy level examples, sothat, i can practice.

I regularly followed examples given in the ICEM tutorials, now I want few more geometry for practice.

I use Ansys 12.1
I would be very thankful if you guide me further for my learning.

Topology
 

In addition to practice, having the right topology (blocking strategy) really helps. If you can show an image of what you want to block (or a similar configuration), I can help with the blocking topology...

Simon

Image of Centrifugal pump
 

Here I have attached a image geometry of centrifugal pump, i want blocking and hexa meshing of this pump.
The main trouble while blocking are: blocking of 3D impeller with assembled casing. If you have some idea of turbo machinery mesh, please share with me.

Thank YouAttachment 3017

if u send me your cad file, maybe i can help u.
shad.khosh@yahoo.com

Hi,
I want blocking and hexa meshing of pump for long long time!Do you have idea of turbo machinery mesh, please share with me! thank you!
student_yy@126.com

hi
i am trying to hexa mesh a mixing tank...
i can somehow make it for the turbines inside the tank.. but for the tank the meshes are hanging without any proper connectivity
someone please help me out..

I am actually quite experienced with hexa meshing mixing tanks. But your question doesn't give me any clues as to your actual problem.

hi,
wel, i am doing a single phase simulation of stirred tank reactors with multiple impellers.. using Multiple frame reference model.. i am still a beginner but somehow i made it till hexa meshing a rushton turbine (one of the impellers used).. for pitch blade where in the blades are inclined at 60 deg in my case.., i dont know how to mesh it.. i have used many option like align edges in line and so on.. still one of the blocks remain unatached.. how to get over it?

and also in meshing the entire tank domain the meshes are perfect except for the area of the interface..
can u help me out?
i have atached a part of my meshing..
the blocks are not aligned to the surface of the tanks properly..

Communication Gap.
 

I don't really know what this means Do you have a discontinuity in your model? Did you create the blocking by splitting (top down), or did you use a bottom up method to create blocks manually from verts? If the latter, then you need merge verts to join blocks. You must join all the verts and topology must match if you want the mesh to flow between the blocks.

Also, I don't quite get this (and you picture didn't help enough, although the right picture might). Do you mean the surface mesh is not properly associated? Or do you mean internal blocks edgesare not following the shape of the outer edges? Or do you mean your topology doesn't properly capture the geometry?

Sorry we are having a communication gap. :o

hi,
my answer will be yes for the last three qns...
see, i have manually associated vertex with edges. and i have done that part right.. as u can see (tho pic not of good quality).., the tank has three interfaces in it for three rotating domains.. for the top two interfaces meshing is perfect.. while for the bottom, the meshes are not connected properly... edit mesh option doesnt seem to work good with this..
i am stuck up with this!
and also the mesh from tank top to bottom are not aligned to the surface properly...
rather aligning outwards its aligned inward..

Sir , i am new in CFD simulation ,and i working on simulation of centrifugal pump ,the diffucult that i could not draw all the compenents of pump as diffuser , volute and impeller with icem .
please would you send me a tutorials or any guide to perfrmed this drawing with ICEM , also if it's possible to send me your file ICEM of the pump you have already worked with the curves of perfromance .
thanks in aedvance .
Faithfully .

Any help please?

Hexa Meshing
 

Hi PSYMN, I have a problem with the hexa meshing mixing tanks.
When I run my mesh in CFX it appears the error message

ERROR #001100279 has occurred in subroutine ErrAction.
| Message: | |
Floating point exception: Zero divide | | | | | | | | | | | +--------------------------------------------------------------------+ +--------------------------------------------------------------------+
ERROR #001100279 has occurred in subroutine ErrAction. | | Message: |
| Stopped in routine FPX: C_FPX_HANDLER
Can You help me? Tanks.