August 2, 2018 at 9:01 amopenACSubscriber
I have a complex 3D geometry with internal flow. As I try to use volume extract in Ansys SpaceClaim 18.1 (Institute Academic License) for extracting the fluid domain, I do obtain a fluid volume. However, the volume extracted looks poor quality for some reason. The original geometry has much smoother surfaces for the same component.
Has anyone else faced something similar? Is there a precision or a tolerance setting I need to use before volume extraction?
See image-1 for a test surface that is on the actual solid structure. Image-2 shows the surface on the extracted volume corresponding to the above surface. The actual solid looks smooth and the extracted solid looks faceted like in image-2. Interestingly, if I take this surface from my extracted volume and either "detach" it or paste it to a fresh design window, it looks smooth again.
August 2, 2018 at 9:06 am
August 2, 2018 at 9:38 amopenACSubscriber
Thank you for replying, Aniket.
The rendering quality goes from 1(Lowest) to 7(Highest) on my old laptop -- Intel Pentium CPU N3520 @ 2.16GHz.
If I select anything other than 3, the "Recalculate Rendering" Button becomes inactive.
You maybe right about this being a rendering issue, but then why do I see a smoother geometry for the solid structure but not for the extracted volume?
August 2, 2018 at 11:13 ampeteroznewmanSubscriber
I saw the same thing in this example, but I didn't know how to extract that face off the filled volume to study it separately.
August 2, 2018 at 1:23 pmopenACSubscriber
@peteroznewman I also couldn't separate it from the full body by hiding the other faces. If I "Detach" by right clicking on that surface and selecting "Detach", then I can see it separately, but then the surface looks smooth like in the original solid.
I am puzzled what may be going on.
August 6, 2018 at 12:20 pmFrankDAnsys Employee
There is almost no need to put the rendering at 10. This was added for resolving extremely small surfaces on very large models, and has the potential to drag the performance down significantly, on even the highest end graphics cards (this is why it is colored red in the UI.)
You will not be able to distinguish with the naked eye, any improvement over setting 7 (the highest in regular use)
Perhaps, Aniket, you could re-snap your image showing setting 7, so as not to encourage the use of 10?
August 7, 2018 at 5:02 pmopenACSubscriber
I did some more analysis, by taking a simple expanding nozzle like solid. See the attached figure. If I just take my nozzle solid and extract the inner volume, it looks very smooth. However, if I add a large (about 4 times the maximum diameter) outlet domain body to this test nozzle, while my solid still looks smooth, the extracted volume has very poor quality surface to capture the nozzle surface.
Maybe there is an optimization algorithm that comes into play while extracting that has the domain size as its parameter.
I am curious how I can address this.
Of course, for now I think that I can simply do the volume extraction on the nozzle geometry and add the outlet domain on the extracted volume. But, my concern is that there is some tolerance or some parameter I am missing to control the tesselation.
August 8, 2018 at 3:09 amKeyur KanadeAnsys Employee
First you may want to use latest version which is R19.1. Please check it resolves your issue.
If you are importing in Fluent Meshing, then there are Tolerance controls while importing. Please use tolerance of 0.01 or 0.001 while importing in Fluent Meshing.
Also please check by taking geometry from SpaceClaim to Workbench Meshing. You can generate surface mesh in Workbench Meshing for particular part in question and then export .msh file to take it to Fluent Meshing. I would prefer this approach for nozzle so that I can accurately capture all curvatures.
August 8, 2018 at 12:29 pmopenACSubscriber
I tried using the tolerance parameter as 0.001 while importing to Fluent Meshing. The faces on the large outlet domain look much smoother than before, and I can see the number of tessellated faces has increased, but the curve of the nozzle is still poor as though it only knows that piecewise linear geometry with 4 or 5 segments. I am increasingly sure that something is happening during volume extract that affects the extracted faces when the large outlet domain is present.
Thank you for your tips on mixing Workbench meshing and Fluent meshing. I will think about how to do this.
August 9, 2018 at 12:10 pmopenACSubscriber
Thanks for all you suggestions.
For now, I have solved my problem. In case anyone comes across this in future, here are my notes:
1. Extract the fluid volume only from the nozzle geometry using the standard "Volume extract" tool.
2. Above step results in the extracted volume that has surfaces as smooth as the original solid.
3. I add the large outlet volume on this extracted volume of the nozzle. The surface quality remains good in this case.
- The topic ‘Poor quality surface in extracted volume – Ansys SpaceClaim’ is closed to new replies.
Boost Ansys Fluent Simulations with AWS
Computational Fluid Dynamics (CFD) helps engineers design products in which the flow of fluid components is a significant challenge. These different use cases often require large complex models to solve on a traditional workstation. Click here to join this event to learn how to leverage Ansys Fluids on the cloud, thanks to Ansys Gateway powered by AWS.
Earth Rescue – An Ansys Online Series
The climate crisis is here. But so is the human ingenuity to fight it. Earth Rescue reveals what visionary companies are doing today to engineer radical new ideas in the fight against climate change. Click here to watch the first episode.
Subscribe to the Ansys Blog to get great new content about the power of simulation delivered right to your email on a weekly basis. With content from Ansys experts, partners and customers you will learn about product development advances, thought leadership and trends and tips to better use Ansys tools. Sign up here.
- No longer possible to import f3d with 2023?
- line bodies and surface body shared topology
- How to chang unit in Ansys Discovery 2023?
- ANSYSLI Exited or could not read server port ANSYSLI_FNE_PORT
- SpaceClaim Script: Selection by FilterByBoundingBox
- Assignment of revolute joint
- Max/min over time results in AIM
- Axisymmetric model – Rubber seal
- To change language in Ansys Discovery
© 2023 Copyright ANSYS, Inc. All rights reserved.