could not find a side polygon that surrounds the negative area side polygon
 

JOB ABORT invoked by rank 0:
ERROR: could not find a side polygon that surrounds the negative area side polygon
this means the stl file probably has problem areas
(-3.125037e-002 6.871118e-003 -2.067326e-002)

when I check the input.in files, the error appeared. what's mean of the error? and I check the coordinate, and found the point is inside the cylinder.

In this case, CONVERGE executable (flow / combustion solver) has found a problem with the surface geometry and therefore has given the error message you have seen.

To better understand the problem, please open CONVERGE Studio, File > Import case setup, and select your working directory. Using the surface Diagnosis tools (type control+D if diagnosis tab is not open), click "Find" and Studio should find one or more errors with the surface geometry. As you fix the issues (if multiple), you can rerun the diagnosis until all problems are resolved. Studio will highlight the problem areas which makes it very easy to see where the problems are.

I have used the surface Diagnosis tools, but can't find something wrong with surface.

Hi,

Open you case in Studio and create a vertex at location (-3.125037e-002 6.871118e-003 -2.067326e-002) to see where the problem area is. This might help you figure out what is causing the issue. Without looking at your geometry, its hard to tell how to fix it. We can help you find the issue if you can send us the case files to support@convergecfd.com.

Thanks,

Thank you， I have solved it. I have another question: which combustion model is suitable if I simulate knock of Spark Ignition engine

You can either use SAGE detailed chemistry model or G_EQN+SAGE in front of the flame options. I can send you a set of slides which explains the process of modeling engine knock if you can send us an email to support@convergecfd.com asking for them. Please use your official email when contacting CONVERGE support.

Thanks,

can you describe about how to solve this problem in detailed?
 

can you describe about how to solve this problem in detailed?

Excuse me，I have the same question，could I ask you how did you solve it，thanks