[mooby]

Hi PPL,

I want to calculate lift and drag coefficients of wing whose leading edge has a cut so that air can actually go inside the wing and wing is made of porous material . for example nylon.

I use porous jump to simulate nylon. But drag and lift forces can only be calculated on walls , so in my case how should i do it ??

any suggestions would be appreciated

[chocolater]

Originally Posted by mooby

Hi PPL,

I want to calculate lift and drag coefficients of wing whose leading edge has a cut so that air can actually go inside the wing and wing is made of porous material . for example nylon.

I use porous jump to simulate nylon. But drag and lift forces can only be calculated on walls , so in my case how should i do it ??

any suggestions would be appreciated

I have same problem with porous jump. how can calculate drag of it in fluent?
mooby how u solve the problem?

[mooby]

Hi chocolater,

Unfortunately, I am still stuck with the problem. I see no solutions at the moment. If in case you get hold of something let me know

Cheers

Mooby

[Kokemoor]

Theoretically, you could measure the difference in momentum flux at your inlet and outlet to get the total force, then subtract off all of your measurable forces from walls. I've never actually tried this, so I can't guarantee its accuracy, but it seems sound. You could try it on a plain wing without the porous jump first to see if it matches the direct force reading.

[mooby]

Hi Andrew,

It might be an approximate solution .... i doubt in this process viscous forces would be accounted but only pressure forces and in Aerodynamics... viscous forces play a major role

[Kokemoor]

External forces in a momentum balance don't differentiate between pressure and viscous forces, they're treated the same.