Images from CAMRAD II Calculations
The images presented below are taken from calculations performed using CAMRAD II.
hovering rotor;
tip vortices are green and blue, lift is red, downwash is magenta
movie file (1.07 Mb)
note the contraction of the wake and the influence of the tip
vortex from the preceding blade on the loading
rotor
in forward flight (advance ratio 0.15); tip vortices are greens,
bound circulation is purple, lift is violetred, downwash is deeppink;
red arrows are flap bending moments and net rotor force
movie file (1.35 Mb)
note the position of the tip vortices above the blades on the
sides of the disk, the rollup of the wake into two super vortices,
and the variation of the bending loads with azimuth
helicopter in low
speed forward flight (60 knots); tip vortices are greens, blade
normal force and inplane force are violetred and purple (not to
same scale)
movie file (1.22 Mb); bvi movie file (1.07 Mb)
note the blade-vortex interaction on the advancing and retreating
sides
helicopter in
high speed forward flight (160 knots); tip vortices are greens,
blade normal force and inplane force are violetred and purple
(not to same scale)
movie file (0.71 Mb)
note the negative loading on the tip of the advancing blade
rotor at high thrust
(advance ratio 0.23, thrust coefficient divided by solidity 0.13);
blade normal force is red and inplane force is purple; rotating
frame perspective, loads shown on blade at azimuth angle 0 to
360 deg (0 azimuth downstream)
movie file (0.21 Mb)
tandem helicopter
in forward flight (100 knots), with slung load; front rotor tip
vortices are greens, rear rotor tip vortices are purples, downwash
from rotor's own wake is midnightblue, downwash from other rotor's
wake is darkgreen; red cables are to top of slung load; fixed
frame perspective
movie file (0.50 Mb)
note that the wake vorticity is deposited in the air as the
helicopter flies by
highly swept rotor
at low speed (advance ratio 0.10); tip vortices are greens, bound
circulation is darkgreen, downwash is lightgreen; blade flap bending
loads are red, blade lag bending loads are orange; rotating frame
perspective
movie file (0.77 Mb)
rotor
with trailing-edge flap (advance ratio 0.30); tip vortices are
greens, bound circulation is purple, downwash is red
movie file (1.16 Mb); closeup movie file (1.15 Mb)
note the trailed vorticity from the flap edges, and the bending
of blade
hovering helicopter
encountering a large amplitude gust (transient duration 1.5 sec,
step gust starts at 0.1 sec); blade normal force is green, red
arrow is net rotor force; fixed frame perspective
movie file (1.86 Mb)
helicopter
encountering a large amplitude gust in forward flight (100 knots,
transient duration 1.5 sec, step gust starts at 0.1 sec); blade
normal force is green, red arrow is net rotor force; fixed frame
perspective
movie file (0.99 Mb)
helicopter in
forward flight (60 knots); main rotor tip vortices are greens,
tail rotor tip vortices are darkgreen, tail rotor blade lift is
red
movie file (1.82 Mb)
note the influence of the main rotor wake on the tail rotor
airplane with large
propeller (ratio flight speed to tip speed 0.95); vortices from
propeller tip and root and from wing tips are greens, wing and
blade loading are red
movie file (1.36 Mb)
note the influence of the propeller wake on the wing loading