local_stability_axesΒΆ
Rotates the body axes onto stability axes. This rotation is equivalent to the projection of a vector in S onto B.
The stability axes are defined as:
x_s
: parallel to the free stream
z_s
: perpendicular to the free stream and part of the plane formed by the local chord and the vertical body axisz_b
.
y_s
: completes the set
- param dir_urel
Unit vector in the direction of the free stream velocity expressed in B frame.
- type dir_urel
np.array
- param dir_chord
Unit vector in the direction of the local chord expressed in B frame.
- type dir_chord
np.array
- returns
Rotation matrix from B to S, equivalent to the projection matrix \(C^{BS}\) that projects a vector from S onto B.
- rtype
np.array