Design3D Screening error: No mesh quality report file found or readable

Hello, the error may be a little misleading, but generally, this happens if the mesh generation fails thus the quality report is not created.

Examples of the failure are:

- "negative cells" in the mesh generation, if the new parametric blade is not suitable for the Autogrid template

- if the blade was replaced by a shorter geometry that doesn't intersect the hub and/or shroud

- possible mistake or error in case of a multirow optimization

My advice is to open the *.igg file with IGG and check if the mesh looks ok. If it doesn't, go to the design directory, open the job_autogrid and you should be able to find out what's gone wrong.

Let me know how it goes, please!

Hi Domen,

Thanks for the helpful advice. I opened the autogrid file within that directory and got an intersection error between blade and hub shown below. It seems it is as you say in the second point. In your 2nd point, how does the blade being replaced by a shorter geometry occur?

In this file, I then went to expand the blade to intersect the hub. However, expanding the blade resulted in an unusual shape near the hub. It did not end up fully intersecting the hub either.

Expanding only the hub also gave an ''adapt units'' suggestion (Although the parasolids geometry that I linked the initial mesh had units in metres). I increased the sewing tolerance and adjusted the expansion ratio but still did not fully intersect the hub. 



Expanding both hub and shroud did not work either:


In addition to the intersection error, the job file also mentioned that there is a self-intersecting  error:

Not quite sure how that occurred.

So far, the only possible solution I can think of is to adjust the blade geometry in Solidworks to intersect the hub, and restart from the beginning. Is there maybe an easier solution to this problem?

Just to be sure: this geometry comes from AutoBlade, right? The objective is to optimize the impeller while the volute is unchanged. 

If this is correct, I would double-check the parametrization in Autoblade. Where are the sections positioned span-wise?

I think so, I shall get back to you on that one. Yes, after optimizing the impeller I was going to do manual adjustments on the volute.

Initially, the target geometry (geomturbo file from autogrid) did not have sectionally data so I used the slicing option in Autoblade to make three slices at 0.01 0.5 and 0.99 in the spanwise direction for this design.

In the Stream surfaces tab of the model editor, I used 3 primary sections, and their spanwise locations after fitting were at 0 0.49 1

OKOK.

One trick is to let Autoblade extend the blade, you can do that in this menu:

0.05 should be enough. If Autogrid is not able to mesh, then my suggestion would be to check the stream surfaces: if they make a "knot" or they are not following well the endwalls, you can shorten them up and have a proper surface to use to build the section. For example here, I reduced the shroud flow path, the section is built on a shorter surface and it's easier to control.