Our heavyweight helicopter equal in the world does not have
In Rostov started production of the most load-lifting rotary-wing car The Russian holding «Helicopt[...]
Velocity-Potential Integrals
2.2.1 3D potentials
 |
 |
The velocity fields of the
 |
One complication here is that the arctan( ) polar angle can contain some arbitrary multiple of 2n. This requires introduction of a branch cut extending from the vortex point out to infinity in some direction, as shown in Figure 2.8. The angle jumps by 2n and the potential jumps by Г across the branch cut.
 |
 |
 |
The branch cut also appears for a doublet sheet, which has the following potential in 2D.
 |
However, the branch cut now is only on the doublet sheet itself. It does not need to extend to infinity like with a vortex, unless the doublet sheet itself extends to infinity. Figure 2.9 compares the branch cuts of a point vortex and a doublet sheet, the latter being equivalent to two point vortices of opposite sign.
