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Aug 31, 2019, 11:12 AM
aerodynamics is just a theory
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B-Wing Mk.2 - Hyperstalling FIXED!


Disappointed that some hyperstall/microstall tendencies persisted in the B-Wing mk.2, I was about ready to hack off the leading edge of the wing to give it a sharper profile. In fact, I even ran some quick CFD tests of different leading edge designs to see if my extra-round leading edge was causing premature flow separation or other problems.

Quick KFm2 Leading Edge CFD test (0 min 50 sec)


While those simulations were running I decided to go out to my secret test location and run a few other scenarios with the Mk.2 to see if I could reduce the microstalling further.

First Flight: removed the AA battery that was taped on for nose weight (24 grams). Hyperstalling immediately exaggerated and a new 'diving' or 'tucking' tendency arose making it impossible to fly straight and level

Second Flight: added back the AA battery and added a second battery (total 48 grams) for nose weight. Microstalling 99% eliminated! No more tucking and no more bobbing in regular turns (only in very hard, high-g loaded maneuvers which is somewhat expected)


---------Flight Video---------
https://www.instagram.com/p/B1pv_1Ln..._web_copy_link


So for now, I suppose that ends the B-Wing microstalling/hyperstalling mystery... sort of. By changing from a KFm-2 Airfoil to a KFm-4 I saw a large improvement in flight performance. And then by dialing in the CG I was able to eliminate 99% of the remaining issues. The aircraft still doesn't fly perfectly, but that is something that can be tuned in over time (I can live with this considering it has been over 3 years since I built a plane!).

Next Step: Get my FPV pod v2 finished up and go for an FPV maiden
Last edited by corsair2014; Aug 31, 2019 at 12:46 PM.
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