[magicbretzel]

Hi all,

I am have a hard time creating the liner for a simple engine. In the compression ratio tab (in Applications/IC engine), I select liner/head for "boundaries around the combustion chamber", and piston for "piston (moving) boundaries. I get the following error:

ERROR: Could not loft centers of fence loops.

I then created a simple cylinder in a new project, and performed the same exercise, and still get this error. What am I doing wrong?

I'm new to this forum (and Converge), and I hope I'll eventually be able to contribute in the future! I work at a small company, and I'm the only CFD guy. So unfortunately, I don't have a Converge mentor, and my question is probably trivial (but not for me!).

Thanks,
Guillaume

P.S. I could add screenshots if needed.

[MFGT]

Hi,

then welcome to CONVERGE first

Regarding your question, its really that simple.
You need to select all "region0" cylinder boundaries for the combustion chamber, including the piston. Then in the lower area you select the moving piston boundary only.

Multi-select boundaries around the combustion chamber:

Click on the boundaries that surround the combustion chamber. In this example, the combustion chamber consists of all of the boundaries in the Cylinder region.
Piston (moving) boundaries:
Click on the boundary or boundaries that comprise the piston. In this example, this boundary is named Piston.

[MCoil]

Hi-

Are you trying to create the liner and associated boundaries, or are you trying to measure the compression ratio?

If you're trying to measure the compression ratio, then do as stated above.

If you're trying to create boundaries, you're going to want to use the tools in the "Geometry" tab. I think there are some videos on our YouTube channel that show how to do this, else you can contact support@convergecfd.com.

Thanks!

[magicbretzel]

Hi MFGT and MCoil,

I was trying to measure the compression ratio to verify that the case was set up properly. The answer provided by MFGT was the solution. Thank you very much to both of you!