Open main menu
Home
Random
Recent changes
Special pages
Community portal
Preferences
About Wikipedia
Disclaimers
Incubator escapee wiki
Search
User menu
Talk
Dark mode
Contributions
Create account
Log in
Editing
Lift coefficient
(section)
Warning:
You are not logged in. Your IP address will be publicly visible if you make any edits. If you
log in
or
create an account
, your edits will be attributed to your username, along with other benefits.
Anti-spam check. Do
not
fill this in!
==Definitions == The lift coefficient ''C''<sub>L</sub> is defined by<ref name=TWS1.2/><ref>Clancy, L. J.: ''Aerodynamics''. Section 4.15</ref> :<math>C_\mathrm L \equiv \frac{L}{q \, S} = {\frac{L}{\frac{1}{2}\rho u^2 \, S}} = {\frac{2 L}{\rho u^2S}} </math> , where <math>L\,</math> is the [[Lift (force)|lift force]], <math>S\,</math> is the relevant surface area and <math>q\,</math> is the fluid [[dynamic pressure]], in turn linked to the [[fluid]] [[density]] <math>\rho\,</math>, and to the [[flow speed]] <math>u\,</math>. The choice of the reference surface should be specified since it is arbitrary. For example, for cylindric profiles (the 3D extrusion of an airfoil in the spanwise direction), the first axis generating the surface is always in the spanwise direction. In aerodynamics and thin airfoil theory, the second axis is commonly in the chordwise direction: :<math>S_{aer} \equiv c \, s</math> resulting in a coefficient: :<math>C_{\mathrm L, \, aer} \equiv \frac{L}{q \, c \, s},</math> While in marine dynamics and for thick airfoils, the second axis is sometimes taken in the thickness direction: :<math>S_{mar} = t \, s</math> resulting in a different coefficient: :<math>C_{\mathrm L, \, mar} \equiv \frac{L}{q \, t \, s} </math> The ratio between these two coefficients is the thickness ratio: :<math>C_{\mathrm L, \, mar} \equiv \frac c t C_{\mathrm L, \, aer} </math> The lift coefficient can be approximated using the [[lifting-line theory]],<ref>Clancy, L. J.: ''Aerodynamics''. Section 8.11</ref> numerically calculated or measured in a [[wind tunnel]] test of a complete aircraft configuration.
Edit summary
(Briefly describe your changes)
By publishing changes, you agree to the
Terms of Use
, and you irrevocably agree to release your contribution under the
CC BY-SA 4.0 License
and the
GFDL
. You agree that a hyperlink or URL is sufficient attribution under the Creative Commons license.
Cancel
Editing help
(opens in new window)