Lift and drag coefficients vs AoA graphs of a specific NACA profile

[fog37]

TL;DR Summary

How the lift coefficient $C_L$ versus #AoA$curve and the drag coefficient$C_D$versus$AoA## curve are calculated for a specific NACA profile...

Hello,
I would like to understand know how the lift coefficient $C_L$ versus AoA curve and the drag coefficient $C_D$ versus AoA curve are determined for the various tabulated NACA profiles.

Are computer simulation run for the different profiles assuming a certain Reynolds' number? Or can the two curves, the lift coefficient $C_L$ versus $AoA$ curve and the drag coefficient $C_D$ versus $AoA$ curve, be calculated analytically for every profile?

Thank you.

 

[jrmichler]

If you REALLY want to know how lift and drag are calculated, get a copy of Theory of Wing Sections, by Abbott and Von Doenhoff. Read the first five chapters.

I bought my copy back in 1987, and it helped convince me that I did not want to design and build my own airplane.

 

[NatSusan]

Hello there,

Great question! The lift coefficient $C_L$ and drag coefficient $C_D$ curves for NACA profiles are typically determined through a combination of computer simulations and wind tunnel testing. Computer simulations use computational fluid dynamics (CFD) to model the flow around the profile and calculate the lift and drag coefficients at various angles of attack (AoA). Wind tunnel testing involves physically testing the profile in a controlled environment and measuring the lift and drag forces.

Both methods usually assume a specific Reynolds number, which is a dimensionless number that represents the ratio of inertial forces to viscous forces in the flow. This is because the lift and drag coefficients are dependent on the Reynolds number. However, some advanced simulation methods can also account for changes in the Reynolds number.

While it is possible to calculate the lift and drag coefficients analytically for simple profiles, NACA profiles are complex and require the use of simulation and testing for accurate results. I hope this helps to answer your question. Let me know if you have any further inquiries.