DON'T MISS THIS THREAD on energy!

[Dwarf]

You can potentially use a dive to gain Energy if you terminate the dive at a speed that still permits positive Ps and you don't dive too low.  Start the dive from too high a speed or terminate the dive at too high a speed and you lose Energy every time in a prop plane.  Dive too far and you won't be able to regain current altitude at current speed either.

A zero G pushover results in an immediate (and transitory) reduction in Drag, which leads to an immediate (and growing) increase in speed which causes an immediate (and exponentially growing) increase in Drag, which leads to a need to initiate a pullout at some point.  That loads up the airframe even further, bleeding off some of the speed you dove to attain.  Drag is now having a big ole lunch on your E.  At some point, you need to initiate the climb... which once again loads up the airframe and bleeds off speed/momentum that you need to carry you back to where you started.

IF you started from a low enough speed and terminated the dive while you still had a Ps credit, and were very, very careful about the loads you applied at every stage, AND IF you accidentally hit your magical maximum energy transfer speed going back up, you might possibly make it back to where you started with some kind of Energy credit.  Not likely, but possible.

Drag is certainly less at a given speed at zero G than any other loading.  See above for why that really doesn't matter much.

What I said was that the difference in the squares of 525 and 500 is 25625. That is the additional amount that gets multiplied by the Coefficient of Drag to help give you your new total Drag.  Drag may only increase by a small percentage as a result but that percentage is certainly greater than the percentage increase in speed, and speed is only a small percentage higher also. Further, Ps is reduced at best and falls to zero or below at worst as a result.

All of which adds up to this being a very long-shot tactic in practice, even when the conditions are perfect and you hold your mouth just right.

It would be far better Energy Management to preserve or increase your existing altitude and go looking for a different target.

Dwarf

[Badboy]

 

Originally posted by Dwarf:

I won't bore you with the math (it's really arcane and tedious).  If you want to check it for yourself, see: Theory of Flight by Richard von Mises,
Dwarf

Judging by the absurd drag calculations you posted earlier, you would be better advised to read it again yourself.

Badboy


 

[Badboy]

Dwarf

First you claim that you can't gain energy in a dive... Now you say:

 

You can potentially use a dive to gain Energy

You are contradicting yourself!

 

if you terminate the dive at a speed that still permits positive Ps and you don't dive too low.  Start the dive from too high a speed or terminate the dive at too high a speed and you lose Energy every time in a prop plane.

 

What you are saying then, is that if you do it the way I said, it works?

 

IF you started from a low enough speed and terminated the dive while you still had a Ps credit, and were very, very careful about the loads you applied at every stage, AND IF you accidentally hit your magical maximum energy transfer speed going back up, you might possibly make it back to where you started with some kind of Energy credit.  Not likely, but possible.

You are correct, it is possible. That's the point I've been making all along.

 

What I said was that the difference in the squares of 525 and 500 is 25625.

No, what you said was...

 

(remember Drag increases with the square of the speed, not linearly - the difference in Drag between velocities of 500 fps and 525 fps is 25625 x Coefficient of Drag)

Which is very different. I don't think anyone who actually knew what they were talking about could make a mistake like that... do you?
 
 

Drag may only increase by a small percentage as a result but that percentage is certainly greater than the percentage increase in speed, and speed is only a small percentage higher also.

Ohh boy... Now you are really talking nonsense!

All of which adds up to this being a very long-shot tactic in practice, even when the conditions are perfect and you hold your mouth just right.

You started by saying it wouldn't work, even calling it fantasy, now you say it is a long shot... Contradicting yourself again!  

 

It would be far better Energy Management to preserve or increase your existing altitude and go looking for a different target.

Then do that, that will certainly work too, but meanwhile the guys taking my advice will be getting the kills you let get away. Not to mention, that they won't be getting killed as easy as your buddy Nuku  (Image removed from quote.)

Badboy

[Dwarf]

 

Originally posted by Badboy:
Judging by the absurd drag calculations you posted earlier, you would be better advised to read it again yourself.

Badboy

OK, you don't want to take the easy way out.

Total Drag is the sum of all the component drags the entire aircraft experiences.  The parasitic drag formula for each component is:
Dp = Cp x(air density/2) x Velocity squared x Area

Dp = parasitic drag for that component
Cp = Coeficient of drag for that component

For any given altitude all terms on the right hand side of the equation can be reduced to a constant except for Velocity.
Because the density of air is such a tiny number (0.001267 slugs per cubic foot at 20k in a standard atmosphere), this constant is always considerably less than 1.0.

Every part of the aircraft is going to experience parasitic drag no matter what G loading you impose.  The magnitude of that parasitic drag is directly the result of the Velocity you are operating at, squared.

If you operate at a Velocity of 500 fps, you multiply that constant by 250,000.

If you operate at a velocity of 525 fps, you multiply that constant by 275,625.

The difference in those two numbers is 25625.  And, that is the difference in the magnitude of the Drag the aircraft experiences between those two speeds at a loading of zero G.

Dwarf

[Dwarf]

Let's back up a minute.

Nuku presented you with a situation that you've already conceded (in another thread) is impossible.  YOU took that to mean he didn't know what he was talking about and propounded a theory to explain how it might be possible.

The simple fact is, that for the conditions he set forth, and as you have already conceded, your theory doesn't work.  (Except maybe in some simulations whose physics modeling no one seems willing to question.  [EDIT]Possibly making this the next chapter in "How To Game The Game", right along with AW's spin turns and WB's warp rolls.[/EDIT])

In all practical situations involving prop aircraft it doesn't work. (regardless of the speeds employed).

I'm simply willing to allow that... theoretically... it might work under certain VERY special circumstances.  Circumstances far different from the ones Nuku set out.

Dwarf
[EDIT] It is a viable jet tactic though.
Also keep in mind, as was also pointed out in the other thread, that props don't exhibit the molar shaped plot you're basing this theory on.




[This message has been edited by Dwarf (edited 02-07-2001).]

[Dwarf]

 

Originally posted by Badboy:
Dwarf
 Then do that, that will certainly work too, but meanwhile the guys taking my advice will be getting the kills you let get away.
Badboy

hmmmmm... guess you've never heard of Drag-n-Bag.

Dwarf

[Badboy]

Ok, the parts you copied from a book looks alright... Then you said:

 

Originally posted by Dwarf:

The difference in those two numbers is 25625.  And, that is the difference in the magnitude of the Drag the aircraft experiences between those two speeds at a loading of zero G.
Dwarf

You are saying that the difference in the magnitude of the drag on the aircraft between those speeds is 25625... When a difference in speed of 25ft/s would probably only result in a difference somewhere inbetween one and two hundred pounds of drag. The figure you are suggesting is absurd.

Badboy

[Lephturn]

Just something to think about:

We certainly have a simplified model in a simulation like Aces High, as compared to the real thing in any case.  There is no way it could model EVERY possible nuance and change.  Isn't it possible that something like this that would rarely work under special circumstances in real life might just work most of the time if done right in a computer game?

Dwarf, what I can tell you is that it seems to work in Aces High and Warbirds.  Badboy has come up with a plausible explanation for why it works.  Now maybe in real life the added complexities of flight might make it almost impossible to capatalize on this type of thing, but in the sterile, simplified environment we deal with, it works just fine.

I think the simplified "world" we deal with may have something to do with the results.  

------------------
Lephturn - Chief Trainer
A member of The Flying Pigs  http://www.flyingpigs.com
 
"A pig is a jolly companion, Boar, sow, barrow, or gilt --
A pig is a pal, who'll boost your morale, Though mountains may topple and tilt.
When they've blackballed, bamboozled, and burned you, When they've turned on you, Tory and Whig,
Though you may be thrown over by Tabby and Rover, You'll never go wrong with a pig, a pig,
You'll never go wrong with a pig!" -- Thomas Pynchon, "Gravity's Rainbow"

[Badboy]

 

Originally posted by Dwarf:

The simple fact is, that for the conditions he set forth, and as you have already conceded, your theory doesn't work.  (Except maybe in some simulations whose physics modeling no one seems willing to question.

You are confused. I have only ever agreed that it doesn't work in one special situation. It's an exception.

 

I'm simply willing to allow that... theoretically... it might work under certain VERY special circumstances.  Circumstances far different from the ones Nuku set out.

Again, the condition in which it doesn't work is the one Nuku set out, i.e. when both aircraft are at their maximum speed. That's a special case, and very rare. When the aircraft are above their maximum energy transfer speed, the technique still works, it just doesn't begin with a dive.

Dwarf, you seem to be making use of several common fallacies in your arguments that will no doubt fool many, particularly those who don’t appreciate the subtitles of the way in which you have been manipulating the thread. So just for those who haven’t seen those methods before, I’ll explain what you are doing. I don’t believe you are doing it deliberately, because you don’t seem to be that smart.

One of the most common fallacies in polemics is simply failing to accept the burden of proof or asserting a claim without presenting a reasoned argument to support it. That of course would leave most arguments a little hollow, but not if you follow it up, as you have done, with a few more fallacies. All of your messages have begun by making assumptions that no one has disagreed with. By doing that you are using a ploy known as the "Straw Man", a technique of directing your argument against a point that isn’t in dispute simply because it is easier to refute. Of course I agree that if both aircraft are already at their max speed, diving is not the right thing to do… it won’t work, and I believe I have clarified that twice in one thread or another, once before you arrived. Naturally you need to ignore that fact so that you can make repeated attacks on the same point, because like the straw man, it’s easy to knock down. Your arguments also contain several other fallacies. You make creative use of the "Non Sequitur", the false implication that one thing leads logically to another, or simply that because there is a situation in which it doesn’t work, the technique doesn’t work at all. So, in order to reinforce that fallacy you repeat the same point in one guise or another, namely that the technique doesn’t work under the conditions set out by Nuku, which is a nice combination of the "Straw Man" and "Circular Reasoning".  All you have really done is to repeat the obvious several times. Arguing that your claims are true by repeating them in different words and in different threads doesn’t make your point more valid. Nothing you have said is any truer after the third repetition than it was the first time. You have rounded all that off quite nicely by performing inept computations and repeatedly contradicting yourself… An aircraft can’t gain energy in a dive, and then it can… The technique doesn’t work, and then it does. I don’t believe you really have a clue!

The simple fact is that it does work. Aerodynamic theory predicts that it works, and the flight models of almost every current WWII simulation are sophisticated enough for us to observe it in action. Deal with it!

Badboy




[This message has been edited by Badboy (edited 02-07-2001).]

[Soda]

This whole thread is intriguing since I can't really understand how what Badboy says will work (though in no way am I claiming it won't).

My question is, in a pursuit such as has been described (not already at max speed) where does the extra E come that allows you to catch the aircraft?  My understanding of aerodynamics is related more to physics than actual aerodynamics but what actually causes the increase in E that would allow closure on the lead aircraft?  The 0 G pushover doesn't generate E, though it does aid in acceleration, thus producing more speed, an obvious component of closure.  I understand what you are saying, but why does the total maneuver result in a net gain in E (since you would have to both accelerate and climb back to you previous altitude to effect the intercept).

The path that the pursuing aircraft must fly is longer than the flat path, the acceleration component could be greater with 0'G, but the resultant speeds would lead me to believe that the drag over the leg of the flight the pursuer flies would be higher than the fleeing aircraft.  The only way I could see a gain would be in something like prop efficency if the pursuit aircraft accelerated better in a higher speed range than the lead aircraft.

Maybe Dwarf and/or Badboy can clear this up for me... like I said, I'm not saying anyone is wrong, but I'm trying to figure out in my mind why this would work.  Everything I know about physics says it shouldn't in a prop plane.

-Soda

[Dwarf]

Leph -

I agree totally.

This is a simplified situation and not all "real world" effects can, or should be expected to carry over.

I believe this is one.

Is it worth doing the series of integrations necessary to prove it?  Nah.

The only thing I'd really like to caution people about is that what Badboy outlines is really a jet tactic.  Jet engines are marvelous things in many ways and permit some maneuvers that just don't work with a prop plane.  Props make routine a couple of things that are highly dangerous in jets as well, so overall it balances out.

While I firmly believe he booted it in this instance, I'd like to repeat what I've said elsewhere about his article on EM diagrams.
Excellent work.  Something everyone should read at least twice.

Dwarf

[Dwarf]

 

Originally posted by Badboy:
Ok, the parts you copied from a book looks alright... Then you said:

 You are saying that the difference in the magnitude of the drag on the aircraft between those speeds is 25625... When a difference in speed of 25ft/s would probably only result in a difference somewhere inbetween one and two hundred pounds of drag. The figure you are suggesting is absurd.

Badboy

I'm not suggesting anything.  I'm merely pointing out to you the actual numbers that really apply to the situation you propose.

Dwarf

[Andy Bush]

Dwarf

>>Props make routine a couple of things that are highly dangerous in jets as well, so overall it balances out.<<

And what might these be? In the context of air combat maneuvers, that is.

Andy

[Dwarf]

 

Originally posted by Badboy:
Again, the condition in which it doesn't work is the one Nuku set out, i.e. when both aircraft are at their maximum speed.

Ok, Lets backup again.  Nuku started that thread by asking how "when both aircraft are at their maximum speed", the pursuing aircraft was able to catch him utilizing a series of dives.

How was your asserion that under other circumstances you believed it was possible, in any way responsive to his question?

Talk about straw men and manipulating a thread.  The conditions, and your theory that exploits those conditions pertain both to a different type of aircraft, and a different situation than he was asking about.

He was asking why a particular apple was rotten.  You started telling him about oranges.  Why use his legitimate question to confuse the issue by introducing a whole different set of circumstances?  

Simple.  You had a theory you wanted to expound and you'd written an article about that theory you wanted to flog.  So you hijacked the entire thread, and confused everyone who had identical concerns simply to tease them into reading your latest essay.

An interesting exercise in situational ethics.


 

The simple fact is that it does work. Aerodynamic theory predicts that it works, and the flight models of almost every current WWII simulation are sophisticated enough for us to observe it in action. Deal with it!

Badboy

I don't know about anybody else, but it's self eveident to me, that if two aircraft are accellerating from a speed well below their max, one aircraft can do so faster than the other by diving and then using that speed and geometry to shoot down the other aircraft.  I think most of us can get that without fancy charts or an article, or hijacking Nuku's thread to inflate your ego.

Starting your own thread about how to make a minimum time, maximum energy climb would have been the logical and ethical thing to do.  Just as disproving my numbers would be the logical thing to do.  But, they say when you can't argue the facts you argue the law, and, when you can't argue the law, you destroy the character of the witness.

If it works, do it is a philosopy that seems to fit you.  Have fun with it.

Dwarf

[This message has been edited by Dwarf (edited 02-08-2001).]

[Dwarf]

 

Originally posted by Andy Bush:
Dwarf

>>Props make routine a couple of things that are highly dangerous in jets as well, so overall it balances out.<<

And what might these be? In the context of air combat maneuvers, that is.

Andy

Anything involving low speed flight or maneuvering.  Props tolerate stalls and spins rather well.  Such gyrations tend to make the clean air converter in jets stop working.

Dwarf