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[ICEM] Increasing nozzle mesh quality

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Old   May 1, 2021, 04:08
Default Increasing nozzle mesh quality
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hi all,
How can I decrease the skewness of the this area?
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Old   May 1, 2021, 11:21
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Quote:
Originally Posted by saadia View Post
hi all,
How can I decrease the skewness of the this area?
Hello,

Can you please show your blocking?
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Old   May 1, 2021, 12:31
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Yes. This is my blocking.
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Old   May 1, 2021, 14:45
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Did you use an O-Grid to block this? Does not look like it...

If you have, your link edges has probably not been performed correctly. You need to link the tangent lines with the corresponding arc of the circle.
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Old   May 1, 2021, 17:50
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No, I have not used o-grid. I have linked them again but it isn't working for me. Do you think my blocking is the problem here?
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Old   May 1, 2021, 20:19
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Hello,

Then I think therein lies your issue. Using an O-grid in the blocking improves mesh quality. You must create an O-grid then link the edges after that.

I would try that first. There are a lot of videos out there on how to do it, here's a quick little basic tutorial on how to create an O-Grid: https://www.youtube.com/watch?v=B7BdQnuutnQ
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Old   May 3, 2021, 05:17
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I have used O-grid in blocking. everything seems good. But now I'm facing two surface meshes at the blocking interfaces. How can I solve this problem?
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Old   May 3, 2021, 10:53
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Originally Posted by saadia View Post
I have used O-grid in blocking. everything seems good. But now I'm facing two surface meshes at the blocking interfaces. How can I solve this problem?
Sorry, I do not quite understand the problem.

Do you mean instead of surface meshes they should be volume meshes? Are you getting an error or something?
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Old   May 3, 2021, 12:44
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I have overlapping edges at the interface plane. There is a separate Hexa mesh on each face. I have circled them red in figure 3. This isn't required because I need the purple mesh connected to the green mesh. The flow has to move from green mesh to purple mesh but they are not connected as both surfaces have meshed.
I have tried deleting face association to connect both the surfaces but it didn't work. I hope I have clarified the situation.
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Old   May 3, 2021, 13:16
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Oh, I see now. Thanks for clarifying.

Edited to add: You may have to change the area of your surfaces, actually. Like only have the surface in that area for ONE of your pieces.

You need to break the connectivity and only associate that surface with one of the pieces (i.e. the purple piece OR green piece). You can use the delete and add from part functions, respectively, to do this.
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Old   May 3, 2021, 15:59
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It might be the case that there is no connectivity in the first place - between the violet and green blocks at that location.


To test my hypothesis run this feature on a copy of your project:
blocking > split block > extend split: select all edges



If there are no additional edges in the cone, where the in-question bypass is attached, then my hypothesis seems valid.

In that case, you need to make an additional split in the cone block. It must result in the face which matches the bypass' face. That way you can plainly merge those two faces to get a continuous blocking. Just placing them next to each other won't connect them.



If my hypothesis is wrong, you might have an artifact on the face association. To fix this you need to delete the face association on the face which interfaces the bypass and cone.
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Old   May 3, 2021, 16:15
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Quote:
Originally Posted by saadia View Post
Yes. This is my blocking.

I see there is a weird constriction at the nozzle of this device - a hollow cone shape.
It seems you have only one string of block passing through the device and out into the far field. I don't see any edges which extend from the nozzle's outlet into the far field. I see only edges from the outlet cone's largest diameter which result in only one face at the farfield outlet. It seems a likely location for negative elements if you haven't done any special treatments there.



In a typical blocking i would expect a projection of the blocking structure from inside blocking at the nozzle, the covering cone, and the farfield around the nozzle. But there is only a single block at the farfield outlet. I struggle to imagine the blocking you have chosen at that location from these images. Do you have created an unstructured/swept block down stream of the nozzle?
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Old   May 3, 2021, 17:51
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I have an additional edge for the bypass which is moved towards the interface. When I try to delete the face association it ends up with figure 3 mesh. Am I doing it right?
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Old   May 3, 2021, 17:58
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Quote:
Originally Posted by bluebase View Post
I see there is a weird constriction at the nozzle of this device - a hollow cone shape.
It seems you have only one string of block passing through the device and out into the far field. I don't see any edges which extend from the nozzle's outlet into the far field. I see only edges from the outlet cone's largest diameter which result in only one face at the farfield outlet. It seems a likely location for negative elements if you haven't done any special treatments there.



In a typical blocking i would expect a projection of the blocking structure from inside blocking at the nozzle, the covering cone, and the farfield around the nozzle. But there is only a single block at the farfield outlet. I struggle to imagine the blocking you have chosen at that location from these images. Do you have created an unstructured/swept block down stream of the nozzle?
That was the previous blocking, I have updated my blocking now. I hope I have done it right this time.
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Old   May 5, 2021, 08:20
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Quote:
Originally Posted by saadia View Post
I have an additional edge for the bypass which is moved towards the interface. When I try to delete the face association it ends up with figure 3 mesh. Am I doing it right?

I'm still convinced that the face with the deleted association is not connected to the cone's blocking. I think you only moved it to this location, but did not perform enoug merging in that area.
It might be the case that you only merged the edge at the largest radius, but not the rest of the interface.
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