Friday, February 6, 2009

NLF vs. turbulent



I ran some simulations for different airfoils in the same condition:
- cruise at medium low altitude, Cl = 0.4, speed = 0.26 mach, Re = 4000000, wing loading >= 20 lbs/sqft.

I first simulated a large number of different airfoils, but finally only picked the couple of NACAs and the NLF215F with -10 degree negative cruise flap and without.

The NLF215F has a clearly better overall performance all over the Cl range what it comes to Cd. Also the pitching moment of this airfoil becomes low when the cruise flap is at -10 degrees.

2 comments:

Exo Cruiser said...

Hmmm... are you now targeting a lower altitude?

I am targeting all the time somewhere below 10000 ft. Basicly without oxygen and no pressurized cabins.

I run some tests for JavaProp and it seems to give very little difference for propellers at SL or 10 000 ft.

Unknown said...

Well, same wing has to work both on below 10000 ft sufficiently well and still be able to cruise at over 40000 ft. Not every flight can be high altitude flight anyway, it takes a long time to climb up there.

I have been now looking NLF215F since the low drag bucket is easy to move on that up and down (as you can see from the picture in my next post and the NASA TP that I posted earlier).