Lift Coefficient tests

[SgtPappy]

I looked all over the place for this test and found nothing in the BB, though someone hinted at it.

It's a NACA 1945 test that documents the maximum lift coefficients and stall characteristics of various planes including the P-51B/C, F4U and P-38. I think it's the test that HTC has been using for modeling our super F4U that people have been doubting.

On the Complete Waste of Space BB, someone posted the test, but as usual, good, hard to find data is damaged so I could not download it. Does anyone have the test that is on the first post of this link? : http://www.acompletewasteofspace.com/modules.php?name=Forums&file=viewtopic&t=12505

[Badboy]

On the Complete Waste of Space BB, someone posted the test, but as usual, good, hard to find data is damaged so I could not download it. Does anyone have the test that is on the first post of this link? : http://www.acompletewasteofspace.com/modules.php?name=Forums&file=viewtopic&t=12505

There is nothing wrong with the link at that site, it is a link to the official report server and the file is not damaged. I just downloaded it and I can scroll through it perfectly using the adobe acrobat reader. Try again, it may have become corrupted on route.

Badboy

[SgtPappy]

Alright I'll try again without firefox.

When I first tried it i had a notice pop up stating that it was damaged... I hope it works. Thanks.

[Brooke]

C_L_max can also be calculated from power-off stall speed.

Since C_L is defined by L = 0.5 * rho * v^2 * S * C_L, where L = lift, rho = air density, v = airspeed, S = wing area; since L = W at stall; and since C_L = C_L_max at stall,

C_L_max = 2 * W / (rho * v_stall^2 * S)

It's a handy way to calculate C_L_max based on things that are easier to find in literature (stall speed, weight, and wing area).

[Captfish]

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19930092669_1993092669.pdf

[SIK1]

C_L_max can also be calculated from power-off stall speed.

Since C_L is defined by L = 0.5 * rho * v^2 * S * C_L, where L = lift, rho = air density, v = airspeed, S = wing area; since L = W at stall; and since C_L = C_L_max at stall,

C_L_max = 2 * W / (rho * v_stall^2 * S)

It's a handy way to calculate C_L_max based on things that are easier to find in literature (stall speed, weight, and wing area).

Your way a person would have to think. It is much easier to just look up a document and let someone else do all the thinking.

[Brooke]

Your way a person would have to think. It is much easier to just look up a document and let someone else do all the thinking.

Heh!  I suppose.  But -- it's really hard to find C_L_max numbers for aircraft, but pretty easy to find stall speed, wing area, and weight.  So, in the end, my way is the lowest-effort way for a lazy person like me.