Learning Forum

[fa-ri]

Hello Everyone,

I'm working on flow past a 4-rotor drone.

I meshed the geometry using curvature size function and I have a tetrahedrons mesh method. I have attached a picture below,

I ran the simulation and used mesh motion for each rotating volume.

I get " negative cell volume detected in dynamic mesh "so

I reduce the time step but during of my simulation I saw the following error

"floating point exception".

I would be really grateful if anyone could help me

Thank you 

With regards

 

 

[Rob]

You've made the first sensible step by reducing time step, but I think if you're modelling a drone you'd be better looking at using sliding mesh as it's a fairly well defined rotating zone.

 

[fa-ri]

hello rwoolhou

Thank you for your response.

 I attached some pictures of my simulation. Is the mesh acceptable?

fa-ri

 

[Naresh Patre]

There is very high cell jump at the interface. You may also want to reduce this cell jump by refining the mesh at the interface for outer body.

[Rob]

I'd also look at increasing the diameter of the zone surrounding the blades, it's possible the mesh is getting twisted there too. Try and get 2-3 blade widths between the tip and the interface. 

[fa-ri]

 

Thank you for your response.

It was helpful.

 

With regards