DON'T MISS THIS THREAD on energy!

[Lephturn]

A great thread... sorta buried in the General forum.
 http://bbs.hitechcreations.com/smf/Smileys/default/Forum1/HTML/007806.html

Read it all guys... it's a great thread.

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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"

[bike killa]

and here is a simple picture ( i hope helpfull picture )
 

[Lephturn]

That is a good description of using a dive to get into guns rang... however it is not the topic of the thread above.  (Well, the good part anyway.  )

While the above works while just short of guns range, the maximum E gaining speed discussed in the thread will help you close from much farther out.



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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"

[bike killa]

yup  
but i decided to post it here 'cuz topic is let's say "similar" (more or less) and it can be helpfull for a newbies.

[Westy]

or BadBoys new article:
 http://www.simhq.com/simhq3/sims/air_combat/energymgmt/

-Westy

[Dwarf]

 

Originally posted by Lephturn:
A great thread... sorta buried in the General forum.
 http://bbs.hitechcreations.com/smf/Smileys/default/Forum1/HTML/007806.html

Read it all guys... it's a great thread.

Read it VERY critically.  Think carefully about the theory being expounded.  If you do you will realize how wrong that theory is.

Dwarf

[Lephturn]

Please explain.

I've discussed this in the thread mentioned, and it makes sense to me.

If there is something I'm missing, please point it out.  I'm more than willing to admit I'm wrong if I've made an error.  Do you deny that this tactic works, or that it should work?  Is there some assumption here we've made in error?  Even re-reading it I don't see the problem at this point.

------------------
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"

[Dwarf]

To be sure we're not referring to different articles again... and I do apologize for my mistake in thinking the 2 URLs referred to a single article... I'm talking strictly about http://bbs.hitechcreations.com/smf/Smileys/default/Forum1/HTML/007806.html  and the linked article referenced within that thread.

See my post near the end of that thread for a fuller explanation.  The short version is that you cannot sacrifice altitude in a prop plane without also losing Energy.  And, unless you can somehow GAIN energy you cannot overtake the lead aircraft in the scenario Nuku started with.
 
Badboy's other article, covering EM diagrams and how you use them to properly employ your aircraft, is both correct and very well presented.

Dwarf

[Badboy]

 

Originally posted by Dwarf:

The short version is that you cannot sacrifice altitude in a prop plane without also losing Energy.

It is infact the quickest way to gain energy, unless of course you are already at your maximum speed and critical altitude.

 

And, unless you can somehow GAIN energy you cannot overtake the lead aircraft in the scenario Nuku started with.

I agree.

Badboy

[Andy Bush]

Dwarf

Can you fill out your profile a bit more, please? I don't mind strong opinions, but it helps to know a little more about where they are coming from.

Andy

[Dwarf]

All you gain by diving is speed, and there's more to Energy than merely speed.  

The physics of propellor driven flight are such that you can never gain enough speed in a dive to make up for the Energy you lose in altitude.  Drag and propellor dynamics see to that.

Careful Energy management can minimize the loss you incur in the dive, but unless you can accelerate to a greater speed at your current altitude, or climb to a higher altitude and accelerate to the same or greater speed there, you won't have increased your Energy state.

Dwarf

[Dwarf]

Andy -

No Thanks.

I don't ask anyone to accept anything I say without verifying it first.

This isn't about opinion, or who has the better reputation or credentials, but about which are the relevant facts.

Never accept any theory without verifying it for yourself, no matter how reliable the source.  Everyone makes mistakes.

Dwarf

[Andy Bush]

Dwarf

You appear to know something about this subject...and I admit, I don't.

With regard to this statement..."Careful Energy management can minimize the loss you incur in the dive"...what techniques do you recommend to accomplish this?

You said, "The physics of propellor driven flight are such that you can never gain enough speed in a dive to make up for the Energy you lose in altitude. Drag and propellor dynamics see to that". Would you explain this please.

I just noticed your last post. You are right...this is not about anyone being 'better' at anything...but you plainly stated that another person was wrong in what he wrote. OK. That may or may not be. The burden is on you to demonstrate why. As it stands now, you are only willing to tell us to go figure it out for ourselves.

That's not very forthcoming on your part. An explanation or a reference would be better, as would be a more complete profile that would allow the rest of us to make our own judgement about the validity of your posts.

Andy

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

[Badboy]

 

Originally posted by Dwarf:
All you gain by diving is speed,

You made the same point in another thread and I disagree.

But firstly, the method doesn't depend on gaining energy during the dive, no one said it did. The main reason for diving is to get you to the speed where you do gain energy at the fastest rate, as quickly as possible. The speed for best energy transfer. You could accelerate to it in level flight, it would just take longer.

Now, regarding energy gain in the dive, you will gain energy in a dive whenever you do it with positive Ps, just as you would at any other attitude. However, if you do the dive at 0g you will gain more energy than you would if you had stayed level because your induced drag would be much lower. The speed for maximum energy transfer is below top speed and so you will still have positive Ps and still be gaining energy when you pullout.

In the other thread you said:

 

First you have to burn some E converting from straight flight to the dive

I disagree. If you push gently to zero g you will see an immediate reduction in drag.

 

All the while Drag is more than negating every Erg you gain in the dive (remember Drag increases with the square of the speed, not linearly

Not so, drag is less at zero g than it is in level flight, speed for speed.

 

the difference in Drag between velocities of 500 fps and 525 fps is 25625 x Coefficient of Drag).

Since Cdo would be about the same at both those speeds you are saying that an increase in speed of 25fps would result in 25625 times more drag. Infact the drag would only increase by a small percentage of its original value.  


Badboy


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

[Dwarf]

Originally posted by Andy Bush:

With regard to this statement..."Careful Energy management can minimize the loss you incur in the dive"...what techniques do you recommend to accomplish this?

Use a gentle push to 0G to initiate the dive.  Be smooth in all stick movements.  Use the absolute minimum G necessary to make corrections or initiate any maneuver.  Stay coordinated and as close to neutral trim force as you can.  Just basic E conservation stuff.


You said, "The physics of propellor driven flight are such that you can never gain enough speed in a dive to make up for the Energy you lose in altitude. Drag and propellor dynamics see to that". Would you explain this please.

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,
Chapter V starts his discussion on Drag
Chapter XI is where he starts talking about propellors
and Chapter XIV is where he discusses performance
or
Theoretical Aerodynamics by L.M Milne-Thompson
He takes things up differently, and you'll be all over his book.

Dwarf