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jayhall0315
09-15-2008, 07:55 PM
Okay, having faced many, many veterans now and some really top notch aces both in full real circumstances and lowly open cockpit servers, I still keep running into guys who swear by using flaps after the initial pass and believe they are floating higher due to their use (that is they feel they are guarding their potential energy advantage well by using them to maintain more altitude).

The only problem ?

After much testing, I can only see that everytime I use flaps, I gain LESS altitude than when I do not. The in-game drag that is generated is simply greater than any possible lift advantage and my altitude is usually much less. Without any nod to being cocky as well, the combat results do not bear out these guys either. I am usually doing quite well against them and maintaining both greater altitude and more potential energy after the initial pass.

So my question is, why do so many swear by using flaps to float to higher elevations ? It seems just using the best climbing speed with no flaps deployed is the best strategy ?

jayhall0315
09-15-2008, 07:55 PM
Okay, having faced many, many veterans now and some really top notch aces both in full real circumstances and lowly open cockpit servers, I still keep running into guys who swear by using flaps after the initial pass and believe they are floating higher due to their use (that is they feel they are guarding their potential energy advantage well by using them to maintain more altitude).

The only problem ?

After much testing, I can only see that everytime I use flaps, I gain LESS altitude than when I do not. The in-game drag that is generated is simply greater than any possible lift advantage and my altitude is usually much less. Without any nod to being cocky as well, the combat results do not bear out these guys either. I am usually doing quite well against them and maintaining both greater altitude and more potential energy after the initial pass.

So my question is, why do so many swear by using flaps to float to higher elevations ? It seems just using the best climbing speed with no flaps deployed is the best strategy ?

M_Gunz
09-15-2008, 08:27 PM
There was a thread over a year ago where Kettenhunde showed use of the rectilinear formula for
zoom climb. You might get him to run through it again now that the troll who buried it over
and over under pages of spam is banned.

X32Wright
09-15-2008, 08:45 PM
What they claim would only be true if they are using planes with 'leading edge' slats like the 109 or Lavochkin. And for me this would be true only if you are on the edge of stall since the 109 would still be responsive due to the slats and adding flaps would further delay the stall. Normally this means 90-110kph in a 109.

If they are talkign about something else then I don't know since I don't do this for any other planes only the 109/Lavochkin and even then I only mostly use this for the 109. Other use it in the mustang and P-39 to delay stalling and still have some control.

M_Gunz
09-15-2008, 09:00 PM
On several sites there are historic time to alt test documents for many different planes.

Please ANYONE show me such a document where flaps were used.

WTE_Galway
09-15-2008, 09:43 PM
Note that not all flaps are the same, there is a massive difference between the effect of Fowler flap on planes like the P38 and the barn door style fitted to a Spitfire.

Also bare in mind that gamers are often not that much up on the theory and hence do not really understand flaps. For example the first thing you learn about flaps in real world flight school is that aside from a lower stall speed they give you a REDUCED angle of attack and more visibility at a particular speed. I have seen threads on this forum where people have obsessively insisted on the opposite.

Altamov_Steppes
09-15-2008, 09:53 PM
Greater Speed makes the wing produce greater lift.

However, if you've got sufficient energy the intitial climb rate may be boosted for a short burst with the use of combat flaps but this is effective for combat bursts only - not for sustained climb rate - and an eye has to be kept on the Vertical Velocity Indicator. Better to lower the nose when in the clear and accelerate to intitial rate of climb airspeed for a climbout.

Flaps are designed to increase the lift co-efficient but the perception from inside the cockpit that it is the flaps making the climb faster is an illusion - much like the illusion when looking behind in a horizonatal turn and perceiving that the aircraft is not horizontal in the turn but diving; when in fact it is horizontal throughout the turn when you look at the instruments.

in fact an aircraft can have its nose nearer to horizontal and be climbing very quickly.

The only flaps I know of that assist performance by not inducing a great drag penalty are fowler flaps - but this performance is more characteristic in making a turn tighter.

Regards KT

Stingray333
09-15-2008, 10:54 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by M_Gunz:
There was a thread over a year ago where Kettenhunde showed use of the rectilinear formula for
zoom climb. You might get him to run through it again now that the troll who buried it over
and over under pages of spam is banned. </div></BLOCKQUOTE>

Is it this thread? 45 pages....

http://forums.ubi.com/eve/forums/a/tpc/f/23110283/m/2421020665/p/1

Going to take a while to read

Stingray

jayhall0315
09-15-2008, 11:08 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by X32Wright:
What they claim would only be true if they are using planes with 'leading edge' slats like the 109 or Lavochkin. And for me this would be true only if you are on the edge of stall since the 109 would still be responsive due to the slats and adding flaps would further delay the stall. Normally this means 90-110kph in a 109.

If they are talkign about something else then I don't know since I don't do this for any other planes only the 109/Lavochkin and even then I only mostly use this for the 109. Other use it in the mustang and P-39 to delay stalling and still have some control. </div></BLOCKQUOTE>

Simple question Wright; How do you specifically activate leading edge slats in-game? I know how to activate the three (combat, ..) main types of regular flaps, but leading edge slats ? .... clueless.

Thanks - Jay

WTE_Galway
09-15-2008, 11:22 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by jayhall0315:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by X32Wright:
What they claim would only be true if they are using planes with 'leading edge' slats like the 109 or Lavochkin. And for me this would be true only if you are on the edge of stall since the 109 would still be responsive due to the slats and adding flaps would further delay the stall. Normally this means 90-110kph in a 109.

If they are talkign about something else then I don't know since I don't do this for any other planes only the 109/Lavochkin and even then I only mostly use this for the 109. Other use it in the mustang and P-39 to delay stalling and still have some control. </div></BLOCKQUOTE>

Simple question Wright; How do you specifically activate leading edge slats in-game? I know how to activate the three (combat, ..) main types of regular flaps, but leading edge slats ? .... clueless.

Thanks - Jay </div></BLOCKQUOTE>
\

Whereas many modern aircraft with slats such as the Cessna Citation business jet or the heavies like the 747 have the slats activated electrically or hydraullically, as far as I know all the aircraft in game with slats were similar to the bf109 where the slats are automatic.

The 109 slats are spring loaded and activate whenever the air pressure at the leading edge can no longer hold them shut.

Just fly a 109 and watch the slats out the window when you pull up into a steep climb and lose speed.

Theoretically the historical best turn in a 109 involved manipulating the slats by pulling hard to tighten the turn and opening the slats and then easing off to regain speed as they closed before repeating it all over again giving you an egg shaped turn. I have no idea if this works in game or not.

OMK_Hand
09-16-2008, 04:10 AM
Here's the intro and summary taken from an article on flyingmag.com, titled "Can Flap Deflection Help You Climb?" By Peter Garrison, dated November 2006.

"I always use flaps for climb. I get more lift that way."
Some would call this statement perfectly logical, because flaps do increase lift and increased lift certainly ought to make an airplane climb faster. Others would say that the reasoning is fallacious, and that flaps, by increasing drag, reduce rate of climb rather than increase it...
... While rate of climb may or may not be affected by a small flap deflection, angle of climb is. Angle of climb is essentially a matter of how slowly you can fly, other things being equal; and so a flap setting that lowers stalling speed without disproportionately increasing drag will allow an airplane to climb at a steeper angle. The deal-breaker here is that proviso about not increasing drag. Flaps do increase drag, and the more you deflect them the more drag you get. Some airplanes can't climb at all with their flaps fully deflected.
In the final analysis"”a phrase often used to make a collection of uncertainties seem more informative than they really are"”the effect of flaps on rate of climb depends on so many factors that no general claim can be made. In my opinion, it is unlikely that any flap deflection has a discernible positive effect upon rate of climb, but I would be interested in seeing evidence"”from actual flight test, not anecdote"”to the contrary."

http://www.flyingmag.com/technicalities/723/can-flap-de...you-climb-page2.html (http://www.flyingmag.com/technicalities/723/can-flap-deflection-help-you-climb-page2.html)

M_Gunz
09-16-2008, 05:07 AM
Stingray:
Starting on page 15 we get the first post of the rectilinear formula.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Kettenhunde

Posted Wed June 13 2007 17:50 Hide Post
How high should my plane zoom????

Characteristics of our theoretical aircraft:

Weight 9000lbs
Thrust in lbs = 1000lbs
Drag in lbs = 500

Zoom climb from 300mph to Vy at a 45 degree angle:

300mph = 441fps
Zoom Angle 45 degrees
Vy = 150mph = 220.5fps

Zoom height:

Sum the forces on the flight path -

9000lbs * sin 45 = 6364lbs
1000lbs – 500lbs – 6364lbs = 5864lbs

a = F/m

m = 9000lbs/32.2 = 279.5 lb-s^2/ft
a= 5864lb/279.5lb-s^2/ft
a = 20.98 ft/s^2

s = (V1^2 – V2^2 ) / 2a

s = (441^2 – 220.5^2)/(2 * 20.98ft/s^2) = 3476.18 ft

3476.18 ft * sin 45 = 2458 ft

All the best,

Crumpp </div></BLOCKQUOTE>

In further Q&A the terms get explained.


But I ask plainly, what plane ever made best climb time to any useful alt with flaps deployed?

Lots of docs and charts here. (http://www.spitfireperformance.com/)

Find one that shows best climb rate with flaps down to any setting.

Even P-38 please; The P-38 Lightning - Evolution of Speed and Climb Performance (http://www.wwiiaircraftperformance.org/p-38/p-38-wayne.html)

It does mention: <BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">The Focke-Wulf 190D-9 and late model Bf-109s had better speed and climb performance than the Lightning, but with boosted ailerons and combat flaps, it was more maneuverable. </div></BLOCKQUOTE>

Which doesn't say at what speeds and doesn't single out the flaps either.
Still I don't expect the grab on, close eyes and insist crowd to bother with whole statements
or anything but the little bits here and there that support their fantasies. The P-40B is
more maneuverable than the P-51D for all that's worth, and the I-15 is more than either one
if you pick the right speeds.

M_Gunz
09-16-2008, 06:06 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by OMK_Hand:
Here's the intro and summary taken from an article on flyingmag.com, titled "Can Flap Deflection Help You Climb?" By Peter Garrison, dated November 2006.

http://www.flyingmag.com/technicalities/723/can-flap-de...you-climb-page2.html (http://www.flyingmag.com/technicalities/723/can-flap-deflection-help-you-climb-page2.html) </div></BLOCKQUOTE>

As that same article points out (and aero sites also show), sustained climb is about power not lift.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Now, why all this talk about drag, when we're interested in climbing and therefore presumably in lift? Because it's not true that excess lift makes an airplane climb. An airplane in a steady climb has essentially the same lift as one in level flight"”just one or two percent more, at most, because in a climb the lift vector is at a slight angle to the vertical. </div></BLOCKQUOTE>

You can raise a plane through lift alone by keeping level and going faster, sure thing.
And then the nose raises so you push the stick forward to maintain your pitch.
Try out-climbing someone who points their nose up by doing that. Yeah, life is just tough.

When the plane is tilted upwards and moving upwards (transition from level established) then the
lift vector from the wings is tilted BACK and often the plane flys slower, but not always
since not everyone starts out at full possible power and can increase power to climb.

If you need a picture, check Fig 2 (http://www.free-online-private-pilot-ground-school.com/Aerodynamics_in_flight.html)

Even with flaps down the lift is still tilted back and once you've slowed down due to the
flaps you don't have more lift. It takes POWER to overcome the backward component of the
back-tilted lift vector which is generally not increased. That's why it is POWER that makes
the climb.

OTOH you can try keeping the nose level, drop those flaps and lift on up faster than...?

Or find a POH for any of these planes that recommends dropping flaps to climb.

Here's Embry-Riddle Aeronautics University on the subject: (http://www.erau.edu/er/newsmedia/articles/wp6.html)

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">With all this talk of excess thrust, one might ask, what does lift have to do with climbs? Many pilots wrongly think it is excess lift that makes an aircraft climb. </div></BLOCKQUOTE>

But read more if you need to. They explain how excess lift deflects the path of the plane
upward which is why when adding speed you have to push the stick forward to maintain your
pitch.

Stingray333
09-16-2008, 12:05 PM
Interesting, thanks for quoting that M_Gunz, going to take me a bit to take it all in

Stingray

LEBillfish
09-16-2008, 12:21 PM
My "guess"......They're like all things in life working on a bell curve of sorts. Too slow and flaps don't help the speed limiting you, you simply adding more drag though adding stability. Adding flaps most likely would help right up till the point the speed is reduced from optimum. It also possible that the reduction in speed due to flaps might either increase of decrease dependant upon speed.

However....As much as they tried to make the sim real world, it's still a sim and bound by the limitations within it such complex shifting factors very possibly not taken into account.

SOooOOoOoooOooo....That means you need to do some testing......See if Tagert or one of these others who use charting software could run some tests though I believe Tagert was killed and eaten by cannibals.

K2

Altamov_Steppes
09-16-2008, 06:16 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Stingray333:
Interesting, thanks for quoting that M_Gunz, going to take me a bit to take it all in

Stingray </div></BLOCKQUOTE>

Then while people are taking all that in, take this in before confusion reigns:

In general terms (for general aircraft and depending on the angle of incidence of the wing and other lesser factors) the most efficient AoA occurs at an angle approximately 4 times lower than the angle of maximum lift.

At this most efficient angle lift is around 12 times greater than drag (from standard Lift/Drag Curve).

Both figures are without flaps.

As has been stated AIRSPEED is the major determinant for maximum ROC (which is what the original question is inferring I think).

Regards KT

M_Gunz
09-16-2008, 07:19 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Stingray333:
Interesting, thanks for quoting that M_Gunz, going to take me a bit to take it all in

Stingray </div></BLOCKQUOTE>

If you can get him free, Kettenhunde (Crumpp) is good about answering questions and helping
with both big picture and straightening details.

The big deal being that speed is the only 2nd order (squared) factor while the rest are 1st
order. The thing is that speed is part of drag and squared within determination of that too
so until all the terms are expanded (into a wider, messier mathematical explanation) it's
not so easily clear how extremes come into play, esp in determining the averages like speed.
In a zoom starting well above maximum level speed it doesn't work the same as one starting
below maximum level speed (speed where thrust = drag) even though a simple work-through won't
show that.
That's only saying that that formula won't always get the exact result but hey, it's ballpark
and more than enough to compare two -very- similar cases except for starting speed.

M_Gunz
09-16-2008, 07:26 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by LEBillfish:
I believe Tagert was killed and eaten by cannibals.

K2 </div></BLOCKQUOTE>

He shot himself in the head at the same time as some of his other logins were discovered.
You could say he was always very self-supportive.
It's not like he's gone.

M_Gunz
09-16-2008, 07:44 PM
Best sustained climb speed of an earlier FW is about 270 kph IAS (depends on alt) and made in
clean configuration, ie without flaps.

If the FW is going faster then a zoom until you slow down to best sustained gets the most.
But go right ahead and pop flaps to zoom with until you slow to the same speed, then compare
that to how high zooming clean to the same best climb speed will get you. And then come and
say the FM is wrong.

Flaps will slow you down and let you climb steeper. To the person *right* behind you, you
have pulled some kind of trick. To the person 300+m back you have presented an easy kill.

Flaps will slow you down and let you turn in a smaller radius as well as not stall while
crawling along. to the person *right* behind you, you have made an incredibly tight turn.
The person 300+m back might have to bank quick to get shots in depending on how fast they
were closing before you put the brakes on.

It's a matter of distances, perspectives and relative speeds that might lead to oversimplified
generalizations like "wow, those flaps make him climb better!".

During the war it was the job of the interceptors to get to high alt as fast as possible.
A lot of lives were on the line.
Please show where interceptors climbed to alt with flaps down to any degree.
I am more than sure that had that been procedure, even unofficial, it would have been documented.

Altamov_Steppes
09-16-2008, 08:03 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by M_Gunz:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Stingray333:
Interesting, thanks for quoting that M_Gunz, going to take me a bit to take it all in

Stingray </div></BLOCKQUOTE>

<span class="ev_code_YELLOW">As you suggest below, some of this is messy)</span>

If you can get him free, Kettenhunde (Crumpp) is good about answering questions and helping
with both big picture and straightening details.

The big deal being that speed is the only 2nd order (squared) factor while the rest are 1st
order <span class="ev_code_YELLOW">(should be V^2 as a vector quantity)</span>. The thing is that speed is part of drag <span class="ev_code_YELLOW">speed is a scalar quantity while drag is a vector quantity so speed can't be part of drag)</span> and squared within determination of that too
so until all the terms are expanded (into a wider, messier mathematical explanation) it's
not so easily clear how extremes come into play, esp in determining the averages like speed.
In a zoom starting well above maximum level speed it doesn't work the same as one starting
below maximum level speed (speed where thrust = drag) <span class="ev_code_YELLOW">(or lift = weight ?)</span> even though a simple work-through won't
show that.
That's only saying that that formula won't always get the exact result but hey, it's ballpark
and more than enough to compare two -very- similar cases except for starting speed. </div></BLOCKQUOTE>

WTE_Galway
09-16-2008, 08:09 PM
velocity is a vector

M_Gunz
09-16-2008, 11:04 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Altamov_Steppes:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by M_Gunz:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Stingray333:
Interesting, thanks for quoting that M_Gunz, going to take me a bit to take it all in

Stingray </div></BLOCKQUOTE>

<span class="ev_code_YELLOW">As you suggest below, some of this is messy)</span>

If you can get him free, Kettenhunde (Crumpp) is good about answering questions and helping
with both big picture and straightening details.

The big deal being that speed is the only 2nd order (squared) factor while the rest are 1st
order <span class="ev_code_YELLOW">(should be V^2 as a vector quantity)</span>. The thing is that speed is part of drag <span class="ev_code_YELLOW">speed is a scalar quantity while drag is a vector quantity so speed can't be part of drag)</span> and squared within determination of that too
so until all the terms are expanded (into a wider, messier mathematical explanation) it's
not so easily clear how extremes come into play, esp in determining the averages like speed.
In a zoom starting well above maximum level speed it doesn't work the same as one starting
below maximum level speed (speed where thrust = drag) <span class="ev_code_YELLOW">(or lift = weight ?)</span> even though a simple work-through won't
show that.
That's only saying that that formula won't always get the exact result but hey, it's ballpark
and more than enough to compare two -very- similar cases except for starting speed. </div></BLOCKQUOTE> </div></BLOCKQUOTE>

You want to quote me then put your picayune comments outside the quotes.

Go calculate drag without speed sometime, genius.
Try lift while you're at it.

Now quit adding DISINFORMATION into what I wrote.

Altamov_Steppes
09-16-2008, 11:22 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by WTE_Galway:
velocity is a vector </div></BLOCKQUOTE>

yes! and...?

'Speed' is often used interchangeably with 'velocity' but the difference is that velocity is a speed which includes a direction e.g. '100 mph vertically'. That is what makes it a vector. Therefore, an object can be moving at a constant speed but not a constant velocity (the thread is seeking clarification about ROC right?)

Therefore, to stretch the point: 'Airspeed' can be a vector because of it's relation to a rotating earth in which case it corresponds to 'velocity'. But speed on the ground is usually conceded as a scalar quantity (s/t) eg '100 mph'.

I just pointed out that there is interdependence in formulas and quantities ought to be defined in precise terms lest a minor error in definition lead to a major error in the conclusion.

'speed' = displacement / time (s/t)
'velocity' = speed of directional displacement
'acceleration' = how quickly an object changes its velocity (change in V / change in time).

It seems to me that the 'rectilinear' formula quoted for 'zoom' climb time is over-simplified. It leaves out things such as power available for thrust, AoA, parasitic drag, torque etc.
But that's alright...who wants to complicate things?

Regards KT

M_Gunz
09-16-2008, 11:43 PM
All those things are in there as was discussed YEARS AGO so just uncross your eyes and quit
the little obfuscation games.

OTOH you could make an actual point instead of playing at making sure no one else does.

Altamov_Steppes
09-17-2008, 12:51 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by M_Gunz:
All those things are in there as was discussed YEARS AGO so just uncross your eyes and quit
the little obfuscation games.

OTOH you could make an actual point instead of playing at making sure no one else does. </div></BLOCKQUOTE>

I thought I made relevant points even several posts back in this thread.

Are you not playing at Trollmaker?

Look again! I only contributed clarification to the thread...I don't only talk to you you know. In fact I think I hope to avoid you.

M_Gunz
09-17-2008, 02:12 AM
Alright then:

1st - don't edit my text inside quote attributed to me -- what I did not write.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Altamov_Steppes:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by M_Gunz:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Stingray333:
Interesting, thanks for quoting that M_Gunz, going to take me a bit to take it all in

Stingray </div></BLOCKQUOTE>

<span class="ev_code_YELLOW">As you suggest below, some of this is messy)</span> </div></BLOCKQUOTE> </div></BLOCKQUOTE>

Even though the color of your remarks is appropriate, set them OUTSIDE parts quoting me.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">If you can get him free, Kettenhunde (Crumpp) is good about answering questions and helping
with both big picture and straightening details.

The big deal being that speed is the only 2nd order (squared) factor while the rest are 1st
order <span class="ev_code_YELLOW">(should be V^2 as a vector quantity)</span>. </div></BLOCKQUOTE>

Your ****-colored remark adds NOTHING here. I don't believe that you did not understand the
use of the word SPEED in that CONTEXT as it is referring to the formula presented.

If you did not then you're perhaps the only one who did not. I note that you did not bother
to assign a direction or otherwise add to or correct the meaning of what I wrote. Your
little markup changes NOTHING. Go get yourself a yellow star to show your mommy.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">The thing is that speed is part of drag <span class="ev_code_YELLOW">speed is a scalar quantity while drag is a vector quantity so speed can't be part of drag)</span> </div></BLOCKQUOTE>

Once again, ditto, excelsior.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> and squared within determination of that too
so until all the terms are expanded (into a wider, messier mathematical explanation) it's
not so easily clear how extremes come into play, esp in determining the averages like speed.
In a zoom starting well above maximum level speed it doesn't work the same as one starting
below maximum level speed (speed where thrust = drag) <span class="ev_code_YELLOW">(or lift = weight ?)</span> </div></BLOCKQUOTE>

Since the plane is in a zoom climb that is inconsequential.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> even though a simple work-through won't
show that.
That's only saying that that formula won't always get the exact result but hey, it's ballpark
and more than enough to compare two -very- similar cases except for starting speed. </div></BLOCKQUOTE>

As for this:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">
It seems to me that the 'rectilinear' formula quoted for 'zoom' climb time is over-simplified. It leaves out things such as power available for thrust, AoA, parasitic drag, torque etc.
But that's alright...who wants to complicate things? </div></BLOCKQUOTE>

Thrust is included in the formula, the power available for thrust results in the thrust so
IT'S IN THERE.

The plane is climbing at a constant angle, the drag is noted, AOA and lift are whatever is
needed to make the climb and result in the TOTAL drag noted -- THOSE ARE IN THERE.

Torque -- you've just hit the level of The Joke himself.

Just in case: what the pilot ate for breakfast is included in the weight, IT'S IN THERE.

If you understand the formula then you will understand that climb rate is _not_ a function
of lift even though yes, du-uh, the plane must have lift it is not substantially different
than the lift required to fly level. It is THRUST that raises the plane.

Of course if you have real problems with all that then you should go teach aerodynamics at
your own special school as that is some of what they teach aero-engineers. I'm sure they
could use your *unique* POV and while you have not shown them I am sure your own techniques
must be as flawless as they are superior. You do the nation, nay the entire world a great
disservice wasting time here when you should be revolutionizing the science of flight.

Poor old me, all I can do is try and understand what my betters have formalized before I was
even born.

F = MA!

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">
Kettenhunde

Posted Wed June 13 2007 17:50 Hide Post
How high should my plane zoom????

Characteristics of our theoretical aircraft:

Weight 9000lbs
Thrust in lbs = 1000lbs
Drag in lbs = 500

Zoom climb from 300mph to Vy at a 45 degree angle:

300mph = 441fps
Zoom Angle 45 degrees
Vy = 150mph = 220.5fps

Zoom height:

Sum the forces on the flight path -

9000lbs * sin 45 = 6364lbs
1000lbs – 500lbs – 6364lbs = 5864lbs

a = F/m

m = 9000lbs/32.2 = 279.5 lb-s^2/ft
a= 5864lb/279.5lb-s^2/ft
a = 20.98 ft/s^2

s = (V1^2 – V2^2 ) / 2a

s = (441^2 – 220.5^2)/(2 * 20.98ft/s^2) = 3476.18 ft

3476.18 ft * sin 45 = 2458 ft

All the best,

Crumpp
</div></BLOCKQUOTE>

Altamov_Steppes
09-17-2008, 07:00 PM
I hope that is a weight off your aerodynamic mind.