Backwash Causes Lift?

writes:

There is nothing after leaving the rotor disk to change the direction
of air flow.

The airplane, helicopter, gyrocopter, and gyroplane all fly straight
and level for the same reason and it isn't air being deflected
downward.

No heavier-than-air aircraft flies without deflecting air downward, unless it
is supported directly by the thrust from its engines.

Mxsmanic wrote in
:

writes:

There is nothing after leaving the rotor disk to change the direction
of air flow.

The airplane, helicopter, gyrocopter, and gyroplane all fly straight
and level for the same reason and it isn't air being deflected
downward.

No heavier-than-air aircraft flies without deflecting air downward,


Yes, they can, and do.

Dynamic lift is usually at play but is by no means required.

Bertie

Bertie the Bunyip writes:

Yes, they can, and do.

Which ones? How do you accelerate an aircraft without accelerating anything
downward?

Mxsmanic wrote in
:

Bertie the Bunyip writes:

Yes, they can, and do.

Which ones? How do you accelerate an aircraft without accelerating
anything downward?


Send me 1,000 bucks and I'll tell you. Otherwise go find out yourself
fruitcake.


Bertie

Mxsmanic wrote:
Bertie the Bunyip writes:

Yes, they can, and do.

Which ones? How do you accelerate an aircraft without accelerating anything
downward?

Acceleration is the second derivative of position.

If the vertical postion of an aircraft is constant, i.e. straight and
level flight, the first derivative of the vertical position is zero and
hence the second derivative is also zero.

Acceleration is the first derivative of velocity.

If the horizontal velocity of an aircraft is constant, i.e. straight and
level flight, the deriviative of the velocity is zero.

An aircraft in straight and level flight is not accelerated.


--
Jim Pennino

Remove .spam.sux to reply.

wrote:
Mxsmanic wrote:
How do you accelerate an aircraft without accelerating
anything downward?
[ ... ]
An aircraft in straight and level flight is not accelerated.

Cute - classic Usenet response. Simultaneously correct, but not really
addressing the original issue.

Jim Logajan wrote:
wrote:
Mxsmanic wrote:
How do you accelerate an aircraft without accelerating
anything downward?
[ ... ]
An aircraft in straight and level flight is not accelerated.

Cute - classic Usenet response. Simultaneously correct, but not really
addressing the original issue.

The point is that talking about aircraft acceleration in straight and
level flight when discussing lift is irrelevant as the aircraft is
not accelerating.


--
Jim Pennino

Remove .spam.sux to reply.

writes:

If the vertical postion of an aircraft is constant, i.e. straight and
level flight, the first derivative of the vertical position is zero and
hence the second derivative is also zero.

Gravity is constantly trying to accelerate an aircraft downwards; something
else has to compensate for this, or it will descend.

An aircraft in straight and level flight is not accelerated.

Because a force is being applied to it that exactly counters gravity. Whence
comes this force?

Mxsmanic wrote in
:

writes:

If the vertical postion of an aircraft is constant, i.e. straight and
level flight, the first derivative of the vertical position is zero
and hence the second derivative is also zero.

Gravity is constantly trying to accelerate an aircraft downwards;
something else has to compensate for this, or it will descend.

An aircraft in straight and level flight is not accelerated.

Because a force is being applied to it that exactly counters gravity.
Whence comes this force?




From somewhere that's waaaaay beyond you , obviously.


Bertie

Mxsmanic wrote:
writes:

If the vertical postion of an aircraft is constant, i.e. straight and
level flight, the first derivative of the vertical position is zero and
hence the second derivative is also zero.

Gravity is constantly trying to accelerate an aircraft downwards; something
else has to compensate for this, or it will descend.

Your original statement:

"How do you accelerate an aircraft without accelerating anything downward?"

Go get a high school physics text and look up the difference between force
and acceleration.

An aircraft in straight and level flight is not accelerated.

Because a force is being applied to it that exactly counters gravity. Whence
comes this force?

Lift, obviously.

--
Jim Pennino

Remove .spam.sux to reply.