Hmmm ... that number 50N looks proper. I see I clipboarded my drag number from cell before adding induced drag ... sorry for confusion. Fortunatelyy someone reads what I write , thanx Howard.
Yes it is right, 2^2 (lift SQR)/pi/5.5(AR) ~= 0.25
means the drag on 0.5m^2 at 25 m/s will be (1.2/2) * 25^2 * 0.25 * 0.5 ~= 50N
Anyway, the speed loss in corner 0.2s is still less than speed loss in climbing
If the model weighs ~60oz (1.7kg), then the airspeed loss would be ~6m/s, out of the original ~24-25 m/s. This isn't negligible.
I just don't seem to be seeing such a dramatic airspeed loss. Maybe I am not even making 10 foot corners though!
Here is some data from a flight last week where I think the airspeed and altimeter are nominally working. This is the wingover. The blue vertical line (at t=178 seconds) is where I think I hammer the plane (Nobler). The white trace is airspeed (mph-- right vertical axis for scale), the red is altitude (feet -left vertical axis for scale), and the purple is the power into the motor (kwatts--right vertical axis for scale).
A couple of caveats--I still feel a little uncertain about how well the sensors are working. For example the airspeed is indicating ~46mph level, while my lap times show ~54mph. The altimeter accuracy is something on the order of 4 feet. Also each tick is 0.1 second.
The max power into the motor coincides with minimum airspeed , which seems to occur a little before the top of the wingover. I wish the data was a little cleaner.
I need to go out and hammer some corners and use my video camera to synchronize when exactly the corner occurs!