Rotor in Hover #165
Replies: 2 comments 2 replies
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Hi. First, I have a question about why the thrust coefficient is so much high ? Did you ran the original |
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My best guess looking at your mid-fidelity CT monitor is that the wake went numerically unstable and the simulation is on its way to blowing up. You can check that in the enstrophy monitor. Also, I recommend visualizing the simulation any time you encounter any unexpected behavior like this (e.g., check whether the hub vortex has reversed and is about to blow up). |
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Hello everyone,
![屏幕截图 2024-04-20 231943](https://private-user-images.githubusercontent.com/85104933/324186570-54b579de-14ec-4ccd-8928-810908dcfc04.png?jwt=eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.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.B5OTFMID8T-XoXW6T9Pc2-edhEXmefpW9kxtN8JSYUQ)
I am studying “Rotor in Hover” case with a four blades rotor and have encountered some problems.
When I use Mid-high fidelity to calculate my rotor, the results are good for the first few revolutions, but then there is a sudden drop in thrust, and the force at the root of the blade is negative.
However, when I change the parameter
![屏幕截图 2024-04-20 234732](https://private-user-images.githubusercontent.com/85104933/324188407-466cb561-8e6c-47a5-928c-edcad749fd7d.png?jwt=eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.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.uSTvfDQBwy14vxfsl6bb_jz26gldT_3Z9MDZRMZqQV8)
sigmafactor_vpmonvlm
the results seem better.I notice that in High fidelity, the parameter
sigmafactor_vpmonvlm
has changed too.Why is it necessary to modify this parameter in High fidelity calculations? And how to determine the value of this parameter?
Or there are other more complex reasons(not about
sigmafactor_vpmonvlm
) cause the problems I meet?Beta Was this translation helpful? Give feedback.
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