Jan Peter Apel
Of course, also insects can only fly on the basic principle
of flying at all, the downward acceleration of air mass. But they have
their flight aligned to that, that they can fly on a point in the air
without moving forward.
Nevertheless, they too moves plates horizontally through the air, as it
makes airplanes. They do this with special designed very light wings,
which they easily can swing fast enough back and forth through the air.
But now it is no longer enough to set the wings front edge towards the
rear edge only so a little higher like on an airplane, where it can
only hardly be seen (about 6 degrees). Insects positioned them with
about 45 degrees and swing they back and forth horizontally, while of
course during the back swing they rotate the blades so that the angle
is 45 degrees again in this direction. The top on the forward swinging
wing is then the bottom during the reverse swing.
picture shows a bumblebee as the heaviest insect relative to its wing
size in that moment, in which the forward swing of the wings has
just at the end. At this moment, these air flows have revealed, which
aerodynamicist to despair. They see no more relationship to the
movements of air, which are previously caused by airplane wings.
picture of the air motions is determined by two large vortices. Out of
this was born a vortex theory, even though vortex never can be active.
Vortices must produced at all once. Vortices are only the consequences
of something, never the cause for something! On bumblebee wings they
are the consequence of the fact, that the wing moves too crossway
through the air.
Although the wings of the bumblebee moved half crossways through the
air, air will be accelerated in the perpendicular direction to the wing
downward. The vertical component of this air force is lift force. But
it is not quite enough. It is only so much how on an airplane in state
Fortunately some more adds. To move the wings half crossways
through the air, the drag against this direction of movement will be
considerably greater by the generation of the vortices. However, this
drag force also acts perpendicular to the surfaces of the wings, with
respect to the vertical 45 degrees from bottom to top, ie in the same
direction as before the air moving down "normal" by its angles of the
It does not matter for which reason air exerts a force on surface,
it is always perpendicular to the surface. Gases cannot exerts shear forces.
The combined product of the two forces generates enough vertical lift
for flying. All air forces interact perpendicular to the wings surfaces.
Because lift is the vertical proportion of air force, by 45 degrees
results a lift force from 71% of the total air force on the wings. With
this bees and all insects and the bumblebee can fly easily!
Even pigeons rotate their wings so to the back side like insects, if
they must start strong vertically. The upper wings surface shows during
the back move down.
The total amount of air that is accelerated by insect wings down, also
includes the drawn vortices: everything flows together down. Even the
little wasp produces an air flow downwards, which is clearly noticeable
in humid weather and near flight over the back of the hand.
More clearly than by the the flight of the bumblebee can the principle
of flying nowhere seen, namely that it is a purely mechanical process
and no mysterious effects such as Bernoulli or Coanda.
Why swings a bumblebee from side to side if they in fact want to stand
still on a place? Because otherwise it would fall in its
self-induced downwash. Therefore it hovers alternately to rest air to