Why doesn't Boeing use supercritical airfoils?

Question

It's my first question & I really want to know the answer from professionals to decide if my new design of airfoil is worth it because the initial test by CFD software (Fluent-ANSYS) indicate that I can beat Supercritical airfoil. **

We know that supercitical "Whitcomb's" airfoil is the best for transonic regime in aero-performance.

So, why Boeing company doesn't use supercritical airfoil concept similar to Airbus especially in the root part of wing. The shape of Boeing's airfoil is differ too much from Airbus. Is have something related with size, pitch moment, structural or intellectual patent rights? *

I really don't like the answers of "confidential data which can't be disclosed" because as I noticed the Lift-drag ratio of Boeing is always less than Airbus & the reason for that very obvious (They don't use Whitconmb's Airfoil Principle)

Answer 1

The Boeing 737 predates the use of supercritical airfoils at Boeing (which again predate the work of Whitcomb, but I digress). In order to keep changes to a minimum, the 737 wing airfoils only got the equivalent of a "nose job" over the years to bring their drag divergence Mach number up. Note that regional airliners fly a bit slower than intercontinental ones, so the use of supercritical airfoils is more of a priority on designs like the 777 and the 787 (and you can be sure that both use excellent supercritical airfoils). The UIUC airfoil plots are for the original 737 series and since the classic series they look a lot more like supercritical ones.

Root airfoils are a different matter again because they must be shaped to counter the Mitteneffekt. Left with the same airfoil over span, the isobars on the upper surface of a swept wing would show less sweep, creating a steep pressure recovery at the center wing (with potential for early stall) and suction peaks near the leading edge at the tips. Therefore, airfoils are changed continuously over span to squeeze the most lift from the wing at high speed.