SimScale CAE Forum

Incompressible Flow around an Aircraft

Hi!
I have a problem with my incompressible flow analysis. Whenever I run an analysis, I see I have a constant pressure field which should be impossible. I have an external flow volume; 15 m/s initial velocity ; cartesian boxes around the aircraft for better meshes and initialized potential flow for better results. Force and moment plots seem normal. My images are at below:








Can you help at this?

Hi @tuncm18,

At a first glance, it looks like some cells are developing very low pressure values, which makes the rest of the domain appear to be at the same pressure (check the range of the pressure legend).

Could you please post the project link (the URL of your project), so we can have a look?

Thanks.

https://www.simscale.com/workbench/?pid=3120999051244111622&mi=spec%3A0cb8dd7d-90ea-4b9b-b189-9a997155503c%2Cservice%3ASIMULATION%2Cstrategy%3A114
Thanks for looking, I appreciate your help Ricardo

No worries.

As I had mentioned in the previous post, the issue here is a small region of the domain which has a very low pressure. For example, inspecting the cells with low pressure using an isovolume filter, we can see where the problematic cells are:

Checking the mesh around this region, we have a very unusual pattern:

This is caused by the CAD model, which is not very clean (optimally we should have a single face here, instead of these hundreds of faces):

Would it be possible to obtain a cleaner profile for the airfoil? In case you are using Onshape, there is a neat profile generator script which gives you a smooth curve (script created by my colleague Darren).

In short, some CAD clean-up is required!

Cheers

I’ll try clean the airfoil and check the results again.
Thanks Ricardo.