# OpenRocket Angle of Attack and Drag Scaling

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#### cajer

##### Member
I see in the open rocket technical guide they reference an fitting function for angle of attack vs drag scaling obtained from wind tunnel results for rocket shaped objects.

"Based on experimental data an empirical formula was produced for
calculating the axial drag coefficient at an angle of attach $\alpha$
from the zero-angle drag coefficient. The scaling function is a
two-part polynomial function that starts from 1 at $\alpha=0^\circ$,
increases to 1.3 at $\alpha=17^\circ$ and then decreases to zero at
$\alpha=90^\circ$; the derivative is also zero at these points."

I can't seem to find the function or the paper it's referencing. Does anyone have any ideas?

#### markkoelsch

##### Well-Known Member
I would start with the master thesis written by the creator of Open Rocket

#### cajer

##### Member
That quote was pulled directly from the master's thesis. There is not reference in there.

#### markkoelsch

##### Well-Known Member
That quote was pulled directly from the master's thesis. There is not reference in there.
Email the author and ask.