Note... mesh may not be closed!

[Nikita Kharlanov]

Hi,

I'm facing a problem and can't figure out what went wrong. I couldn't identify the error through the process of elimination. Here's the situation: I'm conducting an analysis in VSPAero, analysis type R, trying to understand how to fix the yaw instability. In the model file, different versions of tails (tail, tail v2, tail v3, tail v4) have been created. There are no issues with the first three versions, but as soon as I perform an analysis with the classic tail type, the program gets stuck on the error "Note... mesh may not be closed!".

I'm using the VLM method, analysis type R, angle of attack 0, and in the "geometry set," you need to select "Tail V3+V4".

I would really appreciate your help because I have already built the airplane model, and it exhibits strong yaw instability and poor altitude maintenance. I'm trying to find the optimal angles and tail shape.

Thank you in advance.

[Brandon Litherland]

Are you able to upload the model for us to look at?

[Nikita Kharlanov]

I'm sorry, I didn't notice that I didn't add it

вторник, 25 июня 2024 г. в 16:40:05 UTC+3, Brandon Litherland:

[Brandon Litherland]

I ran without any errors in 3.39.1.

[Nikita Kharlanov]

I also have this version  3.39.1  and can’t do an analysis... We’re talking about the same version of the set, aren’t we?

вторник, 25 июня 2024 г. в 17:23:28 UTC+3, Brandon Litherland:

[Nikita Kharlanov]

And there is a question about R analysis in general. If I load a version of the tail with the name "Tail without any version" for testing, then its behavior in real flight is the same as in your video. But to better understand how the analysis works, I removed half of the tail and the fluctuations remained the same, is this normal? Off-topic question, but how to correctly analyze flight stability in yaw?  Thank you in advance.

вторник, 25 июня 2024 г. в 17:29:29 UTC+3, Nikita Kharlanov: