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Hi everyone :)
Are those smooth circular edges even possible?:eek: I am trying to mesh a simple cylinder.I ran snappyhexmesh many times, took all the advice available online, but of no use. :mad: (used sufracefeatureextract also). PFA the image of 'cylinder after using sufracefeatureextract'. Any help would be appreciated. :) |
Your cylinder looks like the snap phase of snappyHexMesh has not taken place, just the castellated mesh was created.
Did you reconstructParMesh/look at the correct timestep 3? |
Hi Horus
I just checked it. Its looks fine now. My bad :o Thank You Turbulence |
having prism layer through to the inlet
I found this thread quite helpful to have my mesh conform more to the geometry. Now, I am having trouble though, getting the prism layer extending all the way to the flow boundaries.
I would like to have something like this mesh (made using ICEM CFD) but as of now I only manage to get this one with the snappyHexMesh utility. I would be glad for some reviews. Thank you. Sam |
You can either make the base cartesian mesh have that kind of underlying structure (but in that case you might as well create the mesh using blockMesh, it can be done), or user layer insertion with uniform layer thickness and lots of layers. This will require some experimentation.
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Hi all,
i would like to extract feature edges in a particular region of my domain. So i am usign -subsetBox option to remove edges outside specified bounding box. Which is the correct syntax? the option -subsetBox ((1 1 1)(2 2 2)) does not work. thank andrea |
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Hi,
you are right! great, now it works. best andrea |
Dear all,,,
I have problem & I think it's related to the feature edge,, Could you help me ? http://www.cfd-online.com/Forums/ope...alve-case.html best regards, Mina |
sHM - edge snapping
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Dear All,
After going through this thread I have fixed some problem, but still I have some problem with edge snapping. the steps I followed is: 1) I executed blockMesh after setting up the case ( 0 cons-> ( poly, trisurf) sys), see fig 1. 2) Secondly, as Bruno's post, the surfaceFeatureExtract command has been executed. Code:
surfaceFeatureExtract -includedAngle 150 -writeObj constant/triSurface/fanGeo.stl fanGeo Code:
castellatedMesh true; please help me to get the good edge snapping. Thanks, Sivakumar |
Hi Sivakumar,
The second image is too far from the blade details. I can't see how many cells you had available for adjusting the mesh to the blade. Best regards, Bruno PS: please use the "[CODE]" markers, as explained on the second link on my signature. |
Dear Bruno,
Thank you very much for your quick reply, I didnt refine any particular region so far. I am trying to make it possible to use of it. after getting some experience I want to do refining region and adding layers and so on... I used the blockMeshDict as follows Code:
convertToMeters 1; Sivakumar |
Hi Sivakumar,
There isn't much I can do with your "blockMeshDict" file. I wanted to see the zoom near the blade's edge, in order to be able to suggest anything useful. Either way, I suggest that you try to use the currently available GUIs, which I'll quote from here: http://openfoamwiki.net/index.php/Sn..._Interfaces.29 Quote:
Bruno |
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Hi Bruno,
I have attached the some of the zoomed figures, Thanks, Sivakumar |
Hi Sivakumar,
The number of cells available along the width of the blade, near this end of the blade, is far from enough. You need at least 2x the refinement that you have right now, near that end of the blade, for snappyHexMesh to be able to give you a barely good mesh. The other detail is that you should keep in mind to have a good base mesh that is well aligned with the blade, if possible. I think the tutorial "incompressible/pimpleDyMFoam/wingMotion", namely the sub-folder "wingMotion_snappyHexMesh", should give you a good idea of how things work. Best regards, Bruno |
Thanks Bruno, I will have a look now.
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Hello all,
I was playing with this surfaceFeatureExtract tool today. Its pretty cool, except that I cannot seem to get it to work. In particular I am playing with flow over a cube. After the eMesh file was created, I ran snappyHexMesh and got the following error: Code:
JHW |
Quote:
I managed to wipe my own ass. The correct snappyHexMeshDict file should have Code:
features Code:
features JHW |
Trailing edge not a problem
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Hi All,
I have been trying to mesh this particular geometry for more than a month now, this is my final resort to ask on the forums. What ever I do the trailing edge of the airfoil is always deforming and the sides of the serrations are always having some deformity and not having the smooth finish as th top of the airfoil. Here is my SappyCode Code:
/*--------------------------------*- C++ -*----------------------------------*\ Quote:
Even the surface layers were showing deformities now and then, about 70% of the airfoil had good surfacelayer mesh but suddenly there is a deformity similar to disscussed by artur, so as now I have planned to follow Arthurs suggestion but If there is any other way to get the surface mesh sorted in snappyHexMesh itself I will be very happy. Quote:
This is just very fine tuning of the surface finish of the mesh as we are interested in the surface boundary layer of the airfoil, the mesh on the surface of the airfoil is absolutely fine only when close to the trailing edge and the thin trailing edge that is causing this issue Thanks for your time and efforts, Hasan K.J |
Greetings Hasan K.J,
I've had this post of yours on my to-do list for quite sometime now and unfortunately I only managed to take a look into it today :(. Without access to the geometry or at least a test case to work with, I will have to guess that:
The other possibility that comes to mind is that you should have a refinement region better refined: Code:
Blade The other possibilities that comes to mind are:
Bruno |
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