[rupak504]

Hi,

I was trying to mesh a geometry with a very sharp corner, as shown in the image. The orthogonal quality falls way below the required 0.1; it is around 0.0358.

And simulation diverges.

howToImproveOrthogonalQuality.PNG

Any idea how to improve the orthogonal quality?

regards

[Martin_Sz]

Improving mesh quality, especially around sharp corners, is crucial for achieving accurate and stable CFD simulations. Here are some strategies to address the low orthogonal quality in your mesh with a sharp corner:

**1. Refine Mesh Around the Corner:**

* **Global Mesh Refinement:** Increase the overall element size of your mesh while keeping a higher refinement level around the sharp corner. This ensures a finer mesh in the critical region without drastically increasing the total number of elements.
* **Local Mesh Refinement:** Utilize local sizing features in your meshing software. Apply a sizing box around the sharp corner and define a smaller element size within that region. This approach refines the mesh only where needed.

**2. Modify Meshing Method:**

* **Switch Meshing Technique:** If you're using a purely sweep or automatic meshing method, consider switching to a more manual approach like patch conforming or advancing front. These methods allow for greater control over element generation and can be helpful for capturing sharp corners.

**3. Split the Geometry:**

For complex geometries with very sharp corners, splitting the geometry at the corner can be beneficial. This allows you to define separate meshes for the faces meeting at the corner and potentially use different meshing methods for each part.

**4. Adjust Meshing Parameters:**

* **Minimum Angle:** Some meshing software offers a "minimum angle" setting. Experiment with slightly increasing this value (within a reasonable range) to allow for slightly skewed elements around the corner while maintaining overall mesh quality. However, be cautious of excessively skewed elements.

**Here are some additional tips:**

* **Visualize Mesh Quality:** Use appropriate visualization tools in your meshing software to identify areas with low orthogonal quality.
* **Convergence Monitoring:** After implementing changes, re-run your simulation and monitor convergence. Improved mesh quality should lead to better convergence and potentially more accurate results.
* **Software Documentation:** Consult the documentation for your specific meshing software. It often provides detailed information on available meshing techniques, local refinement options, and mesh quality parameters.

By implementing these strategies, you should be able to improve the orthogonal quality of your mesh around the sharp corner and achieve a more stable and accurate CFD simulation. If you're still encountering difficulties, consider sharing the image of your geometry (if possible) for a more specific analysis of the meshing challenge.

[Gert-Jan]

What kind of help is this? It is too general to be of any help. Looks like you are just trying to gain traffic to your website.

[mluckyw]

I'm assuming that you've made this using a structured blocking method. If so, try to use Y-block for the transitional area. It should help to a certain extent

[rupak504]

Originally Posted by mluckyw

I'm assuming that you've made this using a structured blocking method. If so, try to use Y-block for the transitional area. It should help to a certain extent

Yes, I have used structured blocking. I get your point, but I am not sure how to do that, can you elaborate on this?

[bluebase]

This post on volute blocking is still valid, have a look:

hex meshing volute

[mluckyw]

Originally Posted by rupak504

Yes, I have used structured blocking. I get your point, but I am not sure how to do that, can you elaborate on this?

It's quite long to explain, but search a tutorial on it. Basically you'll need to collapse a vertices so the block only has 6 total vertices and convert it into a Y-Block