# How do i find a supercritical airfoil for my preliminary design?

The following information is available but i don't exactly know where to get the information about SC Airfoils from. Do Airbus , Boeing use secret airfoil that they don't disclose?

Cruise Speed = 240 m/s or 0.7 Ma; Chord length = 5.5 meters Using online tool to get the Reynolds number gives a very high number of about 85 million. Using the standard setting for kinematic viscosity of $$1.4207E-5$$.

1.How do I find a SC airfoil for a transport jet of about 150 Pa @ 0.7 Ma?

2.Why are my Reynold's number so high? It should be around 25-30 Million.

Answer to the implicit question: Yes, the more recent airliner airfoils are indeed secret. Look for reports like this to see what is out there.

Answer to question 2: Your viscosity is for sea level. Try to use the value for the tropopause and it will be only ⅓ as large.

• Thank you but the link on NASA Technical Paper 2969 is broken. (Both links don't work) Also, that means regional aircraft that don't fly very high have very high Reynold's numbers, which implies they suffer more drag right? May 23 at 10:09
• @SherlockHomies Thank you for letting me know. Now I have changed the link to something hopefully more permanent. May 23 at 11:49