Multirotor - incorrect drag calculation

[ykoshkin-kxp]

Unless I misunderstanding something this piece of code looks to be calculating drag based on the whole propeller area at 100% of properller area size. This would mean it thinks that there are 4 giant discs as far as overall model drag is concerned. I believe there should be a lower ratio for props spectifically.

#AirLib/include/vehicles/multirotor/MultiRotorParams.hpp
Vector3r drag_factor_unit = Vector3r( front_back_area + rotors_.size() * propeller_xsection, left_right_area + rotors_.size() * propeller_xsection, top_bottom_area + rotors_.size() * propeller_area) * params.linear_drag_coefficient / 2;