Originally Posted by
tdracer
Tak, that's NOT why the strake is there, The reason for the strake is is engine out approach - basically if the engine is not running, at higher angles of attack all that airflow spilling out of the inlet can cause flow separation on the wing - the strake acts as a big vortex generator to re-energize the flow and keep it attached over the wing. That's why you'll see strakes on the inboard side of the nacelles of most wing mounted big turbofan engines. Not to say they may not help in the way you're suggesting, but that's not why we put them there.
As for the wings being hung below the wings instead of out front - there are two main reasons for that unrelated to ground clearance (granted, the MAX is a pretty extreme case due to ground clearance). One is rotorburst - sticking the engine out front limits the amount of wing (and associated systems) that are exposed to damage due to a rotorburst. The other is that it's aerodynamically better - if the engine is too close to the wing, at cruise speeds and power settings you get interference drag due to the interaction of the fan flow with the free stream airflow. The drag penalty can be substantial - as much as 2% fuel burn. On the 747-8, they couldn't mount the engines as far forward as they wanted due to flutter issues and had to pay a not insignificant drag penalty as a result.
Nice explanation TD. I have to admit that in my flying years, that go back to the late 80's , I did not know that. In general yes, but not specifically like that. Always appreciate your insights from the engineering side.