Lift Coefficient numbers
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Lift Coefficient numbers
Hello eveyrone. This is my first post here! From what I've seen so far, this forum is absolutely wonderful!
By trade, I'm an Air Traffic Controller who started life as a pilot... weird huh?? I still fly when I can, but I'm in Italy now so I'm pretty much grounded until I get back to the states.
But to the point of the post:
While I'm here, I program flight dynamics for Microsoft Flight Sim and one of the most important inputs is the lift curve. Unfortuneately, I haven't found too much information on airframe-specific numbers. I've looked through the sticky at the top of this forum and didn't see anything jump out at me. Although I could probably spend a whole day surfing from that thread.
Does anyone know where I would be able to find lift curves for airliners? Or perhaps CL0 or CL Max information? Basically anything that I could use to construct the Lift Curve and get it in the right section of the right ballpark would be extremely helpful.
Again, thanks to all who've made and maintain this forum. I'm going to enjoy surfing here.
Take care,
Scott
By trade, I'm an Air Traffic Controller who started life as a pilot... weird huh?? I still fly when I can, but I'm in Italy now so I'm pretty much grounded until I get back to the states.
But to the point of the post:
While I'm here, I program flight dynamics for Microsoft Flight Sim and one of the most important inputs is the lift curve. Unfortuneately, I haven't found too much information on airframe-specific numbers. I've looked through the sticky at the top of this forum and didn't see anything jump out at me. Although I could probably spend a whole day surfing from that thread.
Does anyone know where I would be able to find lift curves for airliners? Or perhaps CL0 or CL Max information? Basically anything that I could use to construct the Lift Curve and get it in the right section of the right ballpark would be extremely helpful.
Again, thanks to all who've made and maintain this forum. I'm going to enjoy surfing here.
Take care,
Scott
Join Date: Jul 2004
Location: Sydney NSW
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how long have you got?
I can take you through as much of the whole darn process of wing design, airframe design, engine design and flying the beggars as I have learnt in thirty odd years. Which wasn't quite enough to make it to the top. Suppose we take a harmless, obsolete lump of metal like the .... oooooh I dunno, ahem, A340-300 and I leave Dr Dmitri Simos to do..... oooh I suppose the B787 on his wondrous web.
I live in Oz, am very fond of food and my drink is Toohey's or Carlton. If you want, pm me. If anybody else wants the plain man's guide and precursor to the practical effects of Power8 I'll happily compose a pdf on why she flies and burns as she does. I'm a bit slow on account of a recent illness but coming round by degrees.
I live in Oz, am very fond of food and my drink is Toohey's or Carlton. If you want, pm me. If anybody else wants the plain man's guide and precursor to the practical effects of Power8 I'll happily compose a pdf on why she flies and burns as she does. I'm a bit slow on account of a recent illness but coming round by degrees.
Join Date: Sep 2002
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If all you want to do is get it "about right" then the following rules of thumb/hints might get you started.
1. Lift curve slope: classically, 2*pi per radian - which is close enough to 0.10 CL per degree for a rough guess. Use a wing area that's about right for the physical wing - not whatever BS number the designers may have concocted.
2. CLmax. If you can find an approach speed (vref) at MLW or takeoff speed (V2) at MTOW then assume they're using reduced reference factors (1.23 or 1.13 respectively), calculate the 1'g' stall speed that results, then use that to work out a CLmax for the config.
For clean config, find the best long range cruise speed, and assume it's at about 1.3-1.35Vs for the config. Back out Vs and hence clean CLmax.
None of those will be the right answer - I can hear the gnashing of teeth as I type - but they'll get you started. At least you'll have something that vaguely resembles the aircraft in question.
1. Lift curve slope: classically, 2*pi per radian - which is close enough to 0.10 CL per degree for a rough guess. Use a wing area that's about right for the physical wing - not whatever BS number the designers may have concocted.
2. CLmax. If you can find an approach speed (vref) at MLW or takeoff speed (V2) at MTOW then assume they're using reduced reference factors (1.23 or 1.13 respectively), calculate the 1'g' stall speed that results, then use that to work out a CLmax for the config.
For clean config, find the best long range cruise speed, and assume it's at about 1.3-1.35Vs for the config. Back out Vs and hence clean CLmax.
None of those will be the right answer - I can hear the gnashing of teeth as I type - but they'll get you started. At least you'll have something that vaguely resembles the aircraft in question.
The classic source for lift and drag vs AoA is Abbott and von Doenhoff which is a steal at $15. However the data is old and may not include more modern sections.
