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-   -   Lift and Drag calculation if wing is porous in nature (https://www.cfd-online.com/Forums/fluent/131417-lift-drag-calculation-if-wing-porous-nature.html)

mooby March 14, 2014 09:22

Lift and Drag calculation if wing is porous in nature
 
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 May 8, 2014 15:05

Quote:

Originally Posted by mooby (Post 480023)
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 May 9, 2014 03:53

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 May 9, 2014 11:49

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 May 11, 2014 03:23

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 May 12, 2014 10:50

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


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