Author Topic: P-38 dive flaps produce no drag  (Read 13818 times)

Offline FLS

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Re: P-38 dive flaps produce no drag
« Reply #60 on: March 18, 2014, 03:00:02 AM »
You disagreed with his method in order to show how fantastically correct you are which was irrelevant to the discussion.


It would have only been ironic if hlbly was incorrect and you were correct. You consistently derail useful and constructive threads with your ego and then whine like a petulant child when criticized for it.


Nice job Gscholz, very good detective work  :salute




You really didn't follow that at all did you?    :lol

He said there is no drag. I agree. The question is how much should there be.

You going to add more useful constructive info now?  

Offline FLS

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Re: P-38 dive flaps produce no drag
« Reply #61 on: March 18, 2014, 03:02:19 AM »
Plenty of flaps in aces high produce less drag than they should.


What's strange is leading edge slats stopping an airplane almost dead when they deploy.

I'd enjoying seeing data that supports your ideas.

Offline nrshida

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Re: P-38 dive flaps produce no drag
« Reply #62 on: March 18, 2014, 06:49:54 AM »
You really didn't follow that at all did you?    :lol

Well let's see...


So we agree the screen shots don't illustrate any part of this discussion?   :D


No we don't agree. The screenshots show that despite lowering two large flaps into the under-wing airflow the aircraft continued accelerating, even at the very edge of its top speed.

Are you just trolling now?

Yeah, the OP has sensed you were positively gushing with agreement and support here.


You going to add more useful constructive info now?  

Criticism can also be constructive.


"If man were meant to fly, he'd have been given an MS Sidewinder"

Offline GScholz

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Re: P-38 dive flaps produce no drag
« Reply #63 on: March 18, 2014, 01:23:09 PM »
Nice job Gscholz, very good detective work  :salute

 :aok
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Offline FLS

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Re: P-38 dive flaps produce no drag
« Reply #64 on: March 18, 2014, 03:26:49 PM »

Yeah, the OP has sensed you were positively gushing with agreement and support here.


Ok nrshida, you continue with the gushing and I'll take the technical questions that you can't handle.  :aok

Offline nrshida

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Re: P-38 dive flaps produce no drag
« Reply #65 on: March 18, 2014, 05:19:08 PM »
Ok nrshida, you continue with the gushing and I'll take the technical questions that you can't handle.  :aok

I think someone who finds a bug no one has found before deserves a compliment. I think someone who does nothing but look for opportunities to demonstrate how correct they are about nothing particularly special as a platform to talk down to people without making a genuine contribution and even derail technical threads to do this should be criticized.   :aok

"If man were meant to fly, he'd have been given an MS Sidewinder"

Offline icepac

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Re: P-38 dive flaps produce no drag
« Reply #66 on: March 19, 2014, 01:05:39 AM »
I'd enjoying seeing data that supports your ideas.

How about you simply try it out yourself rather than sit there like a baby bird squawking away with beak upturned so you can be spoon fed the data you argue.

Try a little experimentation.

Offline FLS

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Re: P-38 dive flaps produce no drag
« Reply #67 on: March 19, 2014, 01:20:12 AM »
How about you simply try it out yourself rather than sit there like a baby bird squawking away with beak upturned so you can be spoon fed the data you argue.

Try a little experimentation.

I tried the flaps. Now please explain how they have less drag then they should.

Offline FLS

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Re: P-38 dive flaps produce no drag
« Reply #68 on: March 19, 2014, 01:43:09 AM »
I think someone who does nothing but look for opportunities to demonstrate how correct they are about nothing particularly special as a platform to talk down to people without making a genuine contribution and even derail technical threads to do this should be criticized.   :aok

You still don't realize you're describing your current behavior here?

Offline nrshida

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Re: P-38 dive flaps produce no drag
« Reply #69 on: March 19, 2014, 02:45:56 AM »
You still don't realize you're describing your current behavior here?

The only point I am asserting I am right about (which was in response to you once again unjustifiably starting on hlbly) is that you troll as much as the next man, just with more subtle packaging. Trying to take the moral high ground afterwards and implying you get trolled by people of lesser intellect while only making contributions is simply your method to wriggle out of criticism for it (to which you seem particularly sensitive to).


Ok nrshida, you continue with the gushing and I'll take the technical questions that you can't handle.  :aok

Let's review your technical contribution to this thread:-

I don't know what it adds to the drag coefficient.

I have a P-38 pilot manual AAF 51-171-1 that doesn't mention drag at all...

I doubt it's overlooked.

<snip>

Start of irrelevant nonsense about the TAS not increasing (even though you later claim you agree with the point you are arguing with).




So we agree the screen shots don't illustrate any part of this discussion?   :D

Are you just trolling now?

(I include this last quote to prevent implications on your part that I'm the only one that thinks you troll).


Then you upload some P-47 flight data which you say states nothing about dive flap drag.


So actually FLS, you've taken precisely NO technical questions that I or anyone else can't handle, contributed nothing technical at all and done nothing but muddy the waters on this issue and harass the OP with irrelevancies and pointless criticism.


Like I say, continuing to use 'begging the question', 'escape hatch', 'moving the goalposts' and your other favourite logical fallacies in this and other threads makes you a hypocrite, and just as much a troll / griefer as if someone were to imply that someone else were an arrogant, egotistical, narcissistic horse's arse with Asperger's, who'd rather derail a thread than be seen to be wrong. Ever, for instance.

I actually find your technical contributions rather simplistic, bookish, unimaginative and yet condescending all at the same time, which is why I hold my present opinion of you.

If you were as technically fantastic as you think you are, genuinely more intelligent than the rest of us, and your only purpose was to make positive contributions (which I think is dishonest of you at best) in an environment of stupid people then why don't you produce equations to calculate the drag of the P-38 dive recovery devices?


« Last Edit: March 19, 2014, 02:51:23 AM by nrshida »
"If man were meant to fly, he'd have been given an MS Sidewinder"

Offline FLS

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Re: P-38 dive flaps produce no drag
« Reply #70 on: March 19, 2014, 04:14:28 AM »
The only data sources posted in this thread that support Gscholz are from me.

Here's a study of dive brakes and dive flaps. It's just a wing but it looks like a P-38 wing.

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20030066111.pdf

Here is more P-47 flight data. Fig.46 is the dive flap acceleration chart. Nothing about dive flap drag.

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20090022749.pdf

The point about IAS is a simple one. Gscholz pointed out that decimals may be rounded up. The same is true when considering air pressure as with speed. How much do you need to descend to change 119 mph IAS to 120 mph with a fixed TAS? If you only need to change 119.49 to 119.50 then it likely isn't very much. If there is an altitude where xxx.49 changes to xxx.50 then there is an altitude a few feet above that which you may be starting from. In any event it says nothing about the dive flaps so the screen shots do nothing to "illustrate" (get it?) the discussion. 


You and hlbly have both made the same contribution to this thread. You both made personal attacks for no reason other than spite. Now I'm thinking you don't know what irony is.  :lol


Offline -ammo-

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Re: P-38 dive flaps produce no drag
« Reply #71 on: March 19, 2014, 05:29:56 AM »
You assume the P-47's altitude changed in the two screen shots?  I assure that it did not.  I was on autopilot and mil power.  The AC's speed was stable before I deployed the dive flaps and actually increased, albeit slightly after they were deployed.

The screen shots I posted do support Gscholz's observation that there is something wrong with how dive flaps are modeled in AH. 
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Offline lyric1

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Re: P-38 dive flaps produce no drag
« Reply #72 on: March 19, 2014, 05:45:19 AM »
« Last Edit: March 19, 2014, 05:51:29 AM by lyric1 »

Offline Randy1

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Re: P-38 dive flaps produce no drag
« Reply #73 on: March 19, 2014, 06:17:30 AM »
There is no information that has been posted that documents dive flap drag in subsonic flow.  The drag from Mach drag from the top wing and mach drag at the dive flap is not documented in this thread. 

My WAG is the paint and unpainted issue of drag and weight over shadow any small drag from a subsonic deployment of the dive flap.

Another interesting point was it is thought the thick airfoil selection by Lockheed was the root cause of the problem.  Later on, raising the tail to a higher position on future designs was a better way to deal with the problems in transonic flow.

Offline FLS

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Re: P-38 dive flaps produce no drag
« Reply #74 on: March 19, 2014, 06:53:11 AM »
I think Cactus's post in the other P-38 thread made it clear that there is some drag even at low speeds and it limits your top speed. Is it a bug or a wishlist item? I expect there's a good reason it's not already modeled, along with a trim change, even if it turns out it should be.