Originally Posted by
SunofAtom
I'm trying to get my head around some of the aerodynamics, and I have yet to find a good explanation of blowback.
I understand the slight right roll (CCW main rotor) when entering transverse flow effect, and the vibrations due to the uneven airflow and forces across the disc as we move through TFE. I'm not understanding why the nose wants to come up as we are getting through TFE and into ETL. I found a couple references to it being due to dissymmetry of lift becoming present and blade flapping starting to occur, but if that's the case, why would the change be so pronounced?
Thanks!
It's just a heap of flapback similar to when you raise the collective in forward flight.
When the disc is completely through ETL, there is a massive increase in AoA all over the disc as the disc moves away from the induced flow. You can tell because not only does it pitch up, it also climbs. Since there dissymmetry of lift and L = AoA x Vē , there is a more lift on advancing blade causing the nose to come up.