How does the F4U-1A beat the Spit 16

[Stoney]

Aerodynamics is applied physics.

To be sure.  A good example is Baumer's turn radius equation.  While the equation's numerator is simply "V^2", that term represents a whole lot of dynamic stuff if you compare everything that makes that number what it is.  Further, thrust to weight is a poor relationship to use when discussing propellor aircraft.  

[thorsim]

no i said maneuvering, it is not the same as turning.

You have repeatedly claimed that size and weight *by themselves*  without reference to lift, power and drag loading will constitute some sort of disadvantage in turning, even if all other factors are equal. This is a proven falsehood. Now you are falsely claiming to have never stated the initial falsehood. But see below.

[hitech]

boomerlv:

Your equations work for the initial acceleration of the roll. Consider why the roll does not continue to accelerate but reaches equilibrium.

To do a complete calculation of the roll rate you need to integrate the lift across the length of the wing (very similar to if you think of the increasing angle of a prop toward the center).

Think about how the lift is effected at the outer portion of the wing as it goes around the circle.

I do not believe you are thinking about the opposite force to the ailerons that creates the steady roll.

HiTech

[boomerlu]

and i think you will find that size and weight may be the two most important factors determining maneuverability ...

in the real world that is ...

To go back to what you've said earlier...
Size? Is a zeppelin maneuverable because it's bigger than a Spit? Weight? Is a 1 lb rock maneuverable?

Lift and thrust. Lift loading and power loading, those are the important factors. S

Oh and your second statement is basically you implying that the flight model is not correct.

[boomerlu]

Your equations work for the initial acceleration of the roll. Consider why the roll does not continue to accelerate but reaches equilibrium.

That's the drag factor. I've used a force balance for the steady state.

To do a complete calculation of the roll rate you need to integrate the lift across the length of the wing (very similar to if you think of the increasing angle of a prop toward the center).

Yes I realized this, but I'm not about to do that integral for the sake of a BBS discussion .

I do not believe you are thinking about the opposite force to the ailerons that creates the steady roll.

That's the drag factor I used in my force balance. Force balance means no acceleration. Maybe I'm wrong on which force I picked, but the drag factor was my guess as to the opposite force.

[BnZs]

 it is the difference between how much one can maneuver and how quickly one can maneuver and it can be a significant advantage/disadvantage and it most often goes to the plane that has less mass to move around.  

Whatever are you talking about here? Turn rate is *precisely* how quickly an airplane can turn.

[boomerlu]

because most of the factors others are using are related to a steady state of flight.  the advantage i presented comes into play when changing the state of flight.  it is the difference between how much one can maneuver and how quickly one can maneuver and it can be a significant advantage/disadvantage and it most often goes to the plane that has less mass to move around.  

How does a plane change its state of flight? Lift, drag, power. More wing area means more available lift both steady state AND at higher AoA. Lift loading is a steady state parameter, but it generally scales well as you increase AoA. But the thing is, we've discounted the differences in scaling regarding increased AoA, with the operative words "all else equal" i.e., we've assumed the wing geometry is the same, only the area changes.

[BnZs]

no i said maneuvering, it is not the same as turning.

So what are we talking about now then? Roll rate? Won't help your asinine "heavier=worse" nonsense, because roll rate will once again be defined by the ratio of the aerodynamic force the ailerons can bring to bear against the resistant forces in the roll axis. If you way of "thinking" were accurate, then the heavier 190 could *never* out-roll lighter Spits, 109s, Laggs, and Yaks.   Come to think of it, the two planes with the best roll rate in the ETO, the 190 and the P-47, were also the heaviest single-engine prop fighters in their respective air forces....hmmm...I guess now I should go about claiming that heavier=better roll rate.  

[boomerlu]

To be sure.  A good example is Baumer's turn radius equation.  While the equation's numerator is simply "V^2", that term represents a whole lot of dynamic stuff if you compare everything that makes that number what it is.

Yup, I fully understand. The numerator is not a number, but rather a function of many things. But I really don't feel like doing calculus or differential equations for a BBS discussion, especially with a subject like aero. 99% of fully accurate real world physics calculations can't be solved exactly but rather must be done either numerically or solved using some approximation/simplification.

On the other hand, a very rough approximation using basic mechanics is enough to see the basic gist.

Further, thrust to weight is a poor relationship to use when discussing propellor aircraft.  

I'm not sure why. But of course this is one front where my ability to reason from physics to aero ends.

[thorsim]

not quite, a plane needs to roll before it can explore its turn rate.  a plane can be great at one and not so good at the other and be easily out maneuvered. there are 6 planes of motion and two directions of roll involved in maneuverability not just left or right.  agility in all 8 defines an aircrafts maneuverability.  at least practically.   

Whatever are you talking about here? Turn rate is *precisely* how quickly an airplane can turn.

[thorsim]

yep i did not consider balloons or rocks in my discussion about airplanes, my apologies ...

although i probably should have said practically instead of "the real world" it would have been more appropriate

sorry for the confusion.

To go back to what you've said earlier...
Size? Is a zeppelin maneuverable because it's bigger than a Spit? Weight? Is a 1 lb rock maneuverable?

Lift and thrust. Lift loading and power loading, those are the important factors. S

Oh and your second statement is basically you implying that the flight model is not correct.

[hitech]

That's the drag factor. I've used a force balance for the steady state.
Yes I realized this, but I'm not about to do that integral for the sake of a BBS discussion .
That's the drag factor I used in my force balance. Force balance means no acceleration. Maybe I'm wrong on which force I picked, but the drag factor was my guess as to the opposite force.

Sorry boomerlu, I miss read you post as not agreeing with change in roll rate, yes I agree with a basic idea that drag (if you think of it that way) increases with the ^2 of the length, and roll force increases linearly with the length.  In Aerodynamics, I tend to think of everything in AOA's when any force is applied as a lifting force, and not a drag slowing the roll.

HiTech

[boomerlu]

not quite, a plane needs to roll before it can explore its turn rate.  a plane can be great at one and not so good at the other and be easily out maneuvered. there are 6 planes of motion and two directions of roll involved in maneuverability not just left or right.

Wow. No.

A rigid object's position is defined by 6 degrees of freedom - [X, Y, Z] (translational freedom) and [roll, pitch, yaw] (rotational freedom).

Each of these has a corresponding velocity component and an acceleration component.

A pilot/airplane traveling horizontally along the X axis (which we assume for simplicity) has direct control over his acceleration in the X direction and indirect control of his acceleration in the other translational directions.

The direct acceleration control comes from throttle and drag. The pilot has indirect control over the acceleration in other translational directions via the use of roll and pitch to orient the lift vector and increase/decrease it. Alternatively the pilot could use roll and yaw to do the same, but it is generally less efficient because the lift provided by yaw is much less than the lift provided by pitch.

Of course this does not contradict your point that roll is important. But BnZs has already covered that.

[hitech]

maneuverability: Ability to change the direction of its velocity vector.

The only force that is perpendicular to the Velocity vector , simply by definition, is lift. Until you accept this very simple premise, there is no use in any discussion, because turning, and changing vel vector are 100% the same term.

HiTech

[boomerlu]

yep i did not consider balloons or rocks in my discussion about airplanes, my apologies ...

My point is simply that the difference between the zeppelin/rock and an airplane is LIFT AND THRUST. By saying "size and weight by themselves are important" you are taking lift and thrust out of the picture. Take that to the extreme, and you get rocks and zeppelins.

Yes they are important, but as we've repeatedly stated (and you seem to have come to agree), more important than size and weight by themselves are their effects on lift loading and power loading. Once again, take those two factors out of the equation and you're left with rocks.

although i probably should have said practically instead of "the real world" it would have been more appropriate

sorry for the confusion.

If that's what you meant, I'll give you the benefit of the doubt. Your history on these boards so far has indicated otherwise, so that's what I inferred.