How to Calculate Vector Forces from Wing Tilt on 757/767 Aircraft?

[Bobthefreeradical]

For any given angle, say if the wings were tilted 28 deg, how can I calculate the vectors acting upon the plane?

 

[Astronuc]

For any given angle, say if the wings were tilted 28 deg, how can I calculate the vectors acting upon the plane?

Isn't one asking for the resultant vector due to the change in airflow (change in momentum of the air)?

Gravity acts in the vertical direction downward. The engines provide thrust along the axis of the aircraft. Then there is the airflow. The aircraft is flying at some velocity, then the inclined wings deflect the airflow downward - in addition to the pressure differential across the wing.

 

[Baluncore]

For any given angle, say if the wings were tilted 28 deg, how can I calculate the vectors acting upon the plane?

28° is a high angle of attack. I expect the wing camber and area will be changed at that AoA by the extension of flaps.

What do you mean by "tilted 28 deg" ?
Why do you need to calculate the forces ?

 

[FactChecker]

Your question is vague. Are you asking about the forces on the aircraft or just on the wing? The full answer is complicated. The "tilt" of the wings might be versus the Earth or versus the wind (angle of attack). You would need to know the aerodynamic forces at that angle of attack. Then you need to combine all the forces in their coordinate system into one force in your desired coordinate system. Aerodynamic forces are usually in the wind axis system. Engine forces are in the airplane body axis system. Gravity is in the Earth locally level axis system. There are also rotational forces and inertial moments to consider. The six degree of freedom (6 DOF) equations of motion (EOM) can be found here.

 

[berkeman]

For any given angle, say if the wings were tilted 28 deg, how can I calculate the vectors acting upon the plane?

It may be easiest to just run your experiments in Microsoft Flight Simulator and use your instruments to figure out the forces during your maneuvers...

https://msfsaddons.com/2023/03/02/rhdsimulations-releases-boeing-767-300er-for-msfs/

 

[berkeman]

For any given angle, say if the wings were tilted 28 deg, how can I calculate the vectors acting upon the plane?

Why do you need to calculate the forces ?

Your question is vague.

I think I know why the OP posted this vague question, but we'll see what they reply with. The Mentors are watching this thread...

 

[Bobthefreeradical]

sorry about that, I'll attempt to be less vague, by tilt of the wing what I probably should have said was that the Roll of the plane being 28 deg off level. ( with all other factors being 0 )

 

[Bobthefreeradical]

28° is a high angle of attack. I expect the wing camber and area will be changed at that AoA by the extension of flaps.

What do you mean by "tilted 28 deg" ?
Why do you need to calculate the forces ?

Sorry, that was an oops on my part, meant to indicate a Roll angle of 28 deg.
there are diagrams in books that have arrows showing the lift vector, & drag & gravity,
Just trying to get a handle on the magnitude of the vector(s) in this case. ( clear 'nuff, or? )

 

[phinds]

sorry about that, I'll attempt to be less vague, by tilt of the wing what I probably should have said was that the Roll of the plane being 28 deg off level. ( with all other factors being 0 )

AAAANNNDD...... you have completely ignored the very specific and very direct question you were asked

Why do you need to calculate the forces ?

Ignoring questions is bad form here on PF.

 

[FactChecker]

sorry about that, I'll attempt to be less vague, by tilt of the wing what I probably should have said was that the Roll of the plane being 28 deg off level. ( with all other factors being 0 )

If there is no roll rate and it is in level flight, then there is some coordinated yaw. The angle of attack would need to increase in order to have a component of lift that would maintain level flight. I'm afraid that I don't know simple equations for it. I will have to leave this for others to answer.

 

[Lnewqban]

... meant to indicate a Roll angle of 28 deg.
there are diagrams in books that have arrows showing the lift vector, & drag & gravity,

Something like this?

 

[FactChecker]

If you just want to represent the lift components when there is a roll angle of $\phi_{deg}$ degrees, the equations are:
$\phi_{rad} = \phi_{deg} * \pi / 180$
$F_{vertical} = F_{lift} * \cos(\phi_{rad} )$
and
$F_{horizontal} = F_{lift} * \sin( \phi_{rad} )$
Where $\cos$ and $\sin$ require inputs ion radians (that is usually true).

 

[Tom.G]

If you just want to represent the lift components when there is a roll angle of $\phi_{deg}$ degrees, the equations are:
$\phi_{rad} = \phi_{deg} * \pi / 180$
$F_{vertical} = F_{lift} * \cos(\phi_{rad} )$
and
$F_{horizontal} = F_{lift} * \sin( \phi_{rad} )$
Where $\cos$ and $\sin$ require inputs ion radians (that is usually true).

...cos and sin require inputs in radians...
??

Doesn't that depend on the look-up table you have or whether the calculator you're using is set for Degrees or Radians?

 

[FactChecker]

...cos and sin require inputs in radians...
??

Doesn't that depend on the look-up table you have or whether the calculator you're using is set for Degrees or Radians?

Good point. Yes, especially if you are using a hand calculator. In most computer programming languages, sin and cos expect inputs in radians. Also Microsoft Excel expects inputs in radians. There may be exceptions.

 

[Practical User]

sorry about that, I'll attempt to be less vague, by tilt of the wing what I probably should have said was that the Roll of the plane being 28 deg off level. ( with all other factors being 0 )

No disrespect , but questions like this are what you get from folks that have no practical experience using the end product of engineers that wish to change terms. Pilots formed their own terms from actually flying the machines. Terms that made logical sense and allowed new pilots to grasp the concepts involved in safely operating airplanes. Thus as you just found out from the diagram providing the force vectors involved with flight these wer calculated long ago.

So as a long time user of airplanes I request that academics and engineers refrain from trying to rename or changing things in aviation until a proper understanding of why the original terms were used. I could cite examples, but I think that your use of the word "tilt" is a good example. the word "tilt" is not nor have I ever heard it used to describe "bank angle". Also one should learn the vernacular before trying to converse in an established discipline. At first I also thought you were talking about "angle of incidence", perhaps like the F8 Crusader had a "tilt" wing, or perhaps "sweep wing" like the F-14 Tomcat. So terms matter when diving into someone else's back yard.

 

[berkeman]

So terms matter when diving into someone else's back yard.

I see what you did there.