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Help and Support Forums => Help and Training => Topic started by: Skyyr on January 15, 2014, 12:40:31 PM

Title: Is induced drag modeled in AH?
Post by: Skyyr on January 15, 2014, 12:40:31 PM: As the title states, does the flight model in Aces High model induced drag?

Thanks!
Title: Re: Is induced drag modeled in AH?
Post by: Karnak on January 15, 2014, 01:00:18 PM: Yes.

Take a Mossie XVI with just the 4k bomb. Test the top speed with the bomb and after dropping it, both tests with the bomb doors closed. It is faster without the bomb than it is with it.
Title: Re: Is induced drag modeled in AH?
Post by: Skyyr on January 15, 2014, 01:29:43 PM: Quote from: Karnak on January 15, 2014, 01:00:18 PM
Yes.

Take a Mossie XVI with just the 4k bomb. Test the top speed with the bomb and after dropping it, both tests with the bomb doors closed. It is faster without the bomb than it is with it.

Simple enough - thank you very much.
Title: Re: Is induced drag modeled in AH?
Post by: Brooke on January 15, 2014, 05:17:09 PM: Another way to know that it does:

Take a plane up and get it going in level flight above, say, 250 mph. Now do a hard flat turn. Notice that the speed rapidly goes down. That's induced drag greatly increasing as you pull g's in the turn.
Title: Re: Is induced drag modeled in AH?
Post by: MachNix on January 15, 2014, 06:44:21 PM: The real answer is No, induced drag is not modeled in AH. The experiments proposed by Karnak and Brooke do happen as they say, but not for the reasons they imply.

Drag in AH is a function of weight and g-loading. Induced drag, the drag created from generating lift, is a function of indicated airspeed and angle of attack (besides the wing shape). The experiment you should be using is to take a bird up at try gliding through a certain altitude, like 2,000 feet, at different speeds using the .speed command to keep the speed constant. Use the E6B to record the descent rates using speeds above and below the best rate of climb speed. At speeds a few miles per hour below best climb speed, the rate of descent should be at its lowest and start to increase as the angle of attack and the induce drag increases. But in AH the rate continues to decrease as if parasitic drag where the only drag acting on the model until you near the stall where drag then increases at the buffet. The flight model is actually quite dangerous if applied to the real world -- you can never get behind the power curve in AH.

Oh, and that thing that is spinning around that looks like a propeller is actually a jet engine in AH. The faster you fly the more thrust it produces. The reason there are not really fast top speeds is parasitic drag is increasing at a higher rate than the thrust. This is why it is sometimes possible to catch a plane that has a higher top speed while flying one with a lower top speed.
Title: Re: Is induced drag modeled in AH?
Post by: Brooke on January 15, 2014, 07:31:48 PM: Quote from: MachNix on January 15, 2014, 06:44:21 PM
The real answer is No, induced drag is not modeled in AH. The experiments proposed by Karnak and Brooke do happen as they say, but not for the reasons they imply.

Yes, they do happen for the reasons we say, and if there were no induced drag in AH, turns and extra bomb load would not sap airspeed.

Quote
Oh, and that thing that is spinning around that looks like a propeller is actually a jet engine in AH. The faster you fly the more thrust it produces.

I don't think so, or the performance of the models would be completely off the flight-test data, which it is not.
Title: Re: Is induced drag modeled in AH?
Post by: BnZs on January 15, 2014, 07:44:06 PM: Quote from: MachNix on January 15, 2014, 06:44:21 PM

Oh, and that thing that is spinning around that looks like a propeller is actually a jet engine in AH. The faster you fly the more thrust it produces. The reason there are not really fast top speeds is parasitic drag is increasing at a higher rate than the thrust. This is why it is sometimes possible to catch a plane that has a higher top speed while flying one with a lower top speed.

If your engine produces more thrust the faster you go, why can't you just hit X and exceed accelerate in level flight till your wings come off?
Title: Re: Is induced drag modeled in AH?
Post by: Karnak on January 15, 2014, 07:58:24 PM: Quote from: MachNix on January 15, 2014, 06:44:21 PM
Oh, and that thing that is spinning around that looks like a propeller is actually a jet engine in AH. The faster you fly the more thrust it produces. The reason there are not really fast top speeds is parasitic drag is increasing at a higher rate than the thrust. This is why it is sometimes possible to catch a plane that has a higher top speed while flying one with a lower top speed.
:rofl

You have no idea what you're talking about.
Title: Re: Is induced drag modeled in AH?
Post by: MachNix on January 15, 2014, 10:26:46 PM: Quote from: BnZs on January 15, 2014, 07:44:06 PM
If your engine produces more thrust the faster you go, why can't you just hit X and exceed accelerate in level flight till your wings come off?

Parasitic drag is increasing at a faster rate then engine thrust. Where trust equals drag is the top speed for level flight. This happens at a speed below the wing-ripping-off speed. For props (in RL) the thrust drops off as you approach the speed of the prop wash -- no more change in momentum of the air passing through the prop disk.

Let us do a little thought experiment. A constant speed prop is turning at 2500 rpm. At slow speeds the prop is in fine pitch. Notice the blades of the prop are wings and they all have their lift vectors pointing nearly forward and creating a lot of thrust. As the aircraft speeds up, the prop pitch becomes more and more coarse so it is still turning at 2500 rpm. Now let's go really fast. The prop is practically feathered. The lift vectors are now perpendicular to the direction of flight and are not producing any thrust. All their lift is fighting against the torque of the engine to keep it at 2500 rpm.

If you want to determine thrust, repeat the experiment I outline earlier and compare the differences in rate of climb/descent at the same speeds. Just to look as some numbers:

Seafire at 6,909 lbs at 2,000 feet:

At 133 IAS (best rate of climb speed), the rate of descent is 1,142 feet per minute with power off giving a drag horsepower of 164.3. At full power the rate of climb is 2,460 fpm net (thrust minus drag) horsepower of 351.2. Therefore the prop is producing 515.5 hp of thrust.

At 350 IAS (well above its maximum level speed), rate of descent is 9,939 fpm, rate of climb at full power is -2,703 fpm, giving a prop thrust of about 1,033 hp.
Title: Re: Is induced drag modeled in AH?
Post by: Mongoose on January 15, 2014, 11:56:14 PM: Quote from: MachNix on January 15, 2014, 06:44:21 PM
Oh, and that thing that is spinning around that looks like a propeller is actually a jet engine in AH.

No, it's a fan to keep the pilot cool. If you don't think so, make it stop and watch him sweat!!! :lol

(I know, old and stupid joke, but I though it fit)
Title: Re: Is induced drag modeled in AH?
Post by: BnZs on January 16, 2014, 08:28:23 AM: Quote from: MachNix on January 15, 2014, 10:26:46 PM
At 133 IAS (best rate of climb speed), the rate of descent is 1,142 feet per minute with power off giving a drag horsepower of 164.3. At full power the rate of climb is 2,460 fpm net (thrust minus drag) horsepower of 351.2. Therefore the prop is producing 515.5 hp of thrust.

At 350 IAS (well above its maximum level speed), rate of descent is 9,939 fpm, rate of climb at full power is -2,703 fpm, giving a prop thrust of about 1,033 hp.

Wait, wait, wait...this sounds like a series of non-sequiturs to me...are you saying these figures mismatch what a Seafire should actually be able to do? Because frankly the claim that AHII has modeled thrust and drag in a completely bogus way, yet each and every plane has speed and climb performance close to that of their historical counterparts, well, that would seem like an awfully lucky series of coincidences.

Also, if AHII doesn't model induced drag, why do the planes lose energy in turns? That is the mechanism by which planes loose speed in turns. If there is no induced drag, why can't a P-51 be flying along at 360 IAS, pull 5gs for a 180 degree level turn, and still be going 360 IAS at the end of the turn???
Title: Re: Is induced drag modeled in AH?
Post by: hitech on January 16, 2014, 10:07:27 AM: MachNix is incorrect.

First AH Absolutely models induced drag. What do you think makes your plane slow down when you turn?

2nd Thrust decreases with speed once the "Stall speed of the prop" is reached, normally around best climb speed.

For normal estimation.

Thrust = Power / Speed;

(http://www.epi-eng.com/images/Redrives/PropEff-01.gif)

A description of "Prop stall speed"

When a plane is standing still the prop is at a finer pitch but a very hi AOA, probably pass stall. When in this state increasing prop witch will increase torque required, but decrease thrust.

Once a plane starts moving forward the airflow from the forward movement is also creating lift on the prop blade and increases drag/torque require. As the plane is accelerating the AOA of the prop is decreasing but since the prop is in a stalled state, the lift is increase. Once the speed is reached that crosses the stall boundary the thrust will start decreasing linearly with the speed (ignoring the small efficiently change do to not all points in the prop having the same AOA).

This "Prop stall" is why the paddle blade prop was created, it lowered the stall speed of the prop which was faster then best climb speed. This lowering increased thrust at best climb speed hence increasing climb rate. It is in essence the same as a helicopter. With long enough blades you can produce more thrust when standing still. But similarly if a helicopter is sinking fast (like moving backwards in a plane) a point can be reached where the propeller/rotor stalls. This is called settling with power. And can not be recovered from by applying more collective but must be recovered from with forward motion.

I have 10 hours rotary instruction logged and have practiced the recovery.

HiTech
Title: Re: Is induced drag modeled in AH?
Post by: BnZs on January 16, 2014, 10:43:20 AM: Yes, my next question was going to be, if induced drag in AHII is simply a function of Gs, why do some planes bleed Gs faster than others? The fact that the Ta-152 with those high aspect ratio wings holds energy so well in turns DESPITE one of the highest wingloadings leads me to believe induced drag is probably *very* well modeled in AH.
Title: Re: Is induced drag modeled in AH?
Post by: MachNix on January 16, 2014, 12:46:24 PM: Quote from: hitech on January 16, 2014, 10:07:27 AM

First AH Absolutely models induced drag. What do you think makes your plane slow down when you turn?

Induced drag is a function of the amount of lift produced. Lift is a function of airspeed and angle of attack. Therefore induced drag is a function of airspeed and angle of attack.

In AH the drag does increase in a turn and the flight model works very well in having the aircraft slow down, but the model has the dragged hooked to something other then angle of attack. What makes me say this is at speeds 20 to 30% slower then the best climb speed, where induced drag should start dominating the power required curve, there is only a small increase in drag. The fact that there is an increase may mean there is indeed induced drag modeled, but is not as strong as one may expect.

For the Seafire, power required goes from about 151 hp required at 109 IAS, which is its lowest, to only 154 hp at 91 IAS near the stall. A 3 hp change in the power requirements is not much considering how much the angle of attack changes between those two speeds.

Am I saying to change the flight model? Definitely not! Everyone would have a cow. But if Skyyr comes in trying to fly the P-51 like he does his A-4 where he is used to unloading the aircraft to increase the acceleration force he feels shoving him in his lower back, he is going to be disappointed. And if he engages in a stall fight thinking he is in a high-drag environment due to induced drag, he is going to be at a disadvantage.

Thanks for responding Hitech and I like your reference to the rotary-wing world where you have to move out from under that column of descending air. :salute
Title: Re: Is induced drag modeled in AH?
Post by: hitech on January 16, 2014, 01:01:13 PM: Quote from: MachNix on January 16, 2014, 12:46:24 PM
but the model has the dragged hooked to something other then angle of attack.

I can 100% guaranty you that Induced drag in AH is a function LiftCo which is a function of AOA.

From wikii
(http://upload.wikimedia.org/math/8/8/8/888310b92a1d3ca18f33cdd5e46c5918.png)

the code cut and pasted from AH.

double simpwingCalcWingIndDragCO(simpWING * Wing)
{
return Wing->IndDragCO * Wing->WingForce.LCO * Wing->WingForce.LCO;
}
Note in the equation from wiki the 3 divisor terms are all constant for a given airframe. My variable (Wing->IndDragCo ) is simply the bottom part of that term.
HiTech
Title: Re: Is induced drag modeled in AH?
Post by: MachNix on January 16, 2014, 02:19:54 PM: Okay,
C_L is coefficient of lift
Pi is pi
e is Oswald's efficiency factor
A is aspect ratio
But if R is Reynolds number, that looks like a problem and should not be there.

You would use the Reynolds number to calculate the zero-lift drag (D_F) for the wing which is a combination of form drag and skin friction drag. But Reynolds number is a function of airspeed and speed should not be a function of any coefficients. If you are dividing by speed here when calculating the drag coefficient, and then later multiplying it by square of the speed in the dynamic pressure term, the induced drag is going to be low. But it is still a function of AOA.

Can you give the link to the wikii info? I could not find it just doing a quick search.
Title: Re: Is induced drag modeled in AH?
Post by: hitech on January 16, 2014, 02:25:58 PM: R is not Renolds

AR is AspectRatio. Hence why I said 3DIVISOR terms not 4

http://en.wikipedia.org/wiki/Lift-induced_drag

HiTech
Title: Re: Is induced drag modeled in AH?
Post by: olds442 on January 16, 2014, 03:33:03 PM: That looks a awful lot like C or C++, what language is aces high in?
Title: Re: Is induced drag modeled in AH?
Post by: hitech on January 16, 2014, 03:49:37 PM: Quote from: olds442 on January 16, 2014, 03:33:03 PM
That looks a awful lot like C or C++, what language is aces high in?

Both, mostly C
Title: Re: Is induced drag modeled in AH?
Post by: MachNix on January 16, 2014, 05:17:44 PM: Quote from: hitech on January 16, 2014, 02:25:58 PM
AR is AspectRatio. Hence why I said 3DIVISOR terms not 4

Already knew that pi was constant so the three terms you mention I thought applied to eAR. So good you are not dividing by the Reynolds number.

Thanks for the link to wikii.

From the first equation on wikii:
D_i = 1/2 * rho * V^2 * S * C_Di

The lift equation has the same form:
L = 1/2 * rho * V^2 * S * C_L

This gives:
(D_i / L ) = (C_Di / C_L)
or
D_i = L * (C_Di / C_L)

Doing some quick, back of the envelop calculations, the C_Di / C_L for the Seafire near the stall is about 0.105 which is in keeping with the Clark Y airfoil on wikii at about 0.1.

So induced drag is modeled and it is based on AOA. But only a 3 hp increase in power required from the minimum drag to the stall? I would have never guessed that to be right.

And I missed lunch! :mad:
Title: Re: Is induced drag modeled in AH?
Post by: Arlo on January 16, 2014, 05:22:10 PM: Quote from: MachNix on January 16, 2014, 05:17:44 PM
So induced drag is modeled and it is based on AOA.

Well there ya go.
Title: Re: Is induced drag modeled in AH?
Post by: pembquist on January 16, 2014, 08:37:56 PM: Hell must be freezing over. I have to salute MachNix for being capable of persuasion by argument. Something I don't think I have ever seen anybody else capable of on this wretched BBS. You have restored my faith in humanity.
Title: Re: Is induced drag modeled in AH?
Post by: olds442 on January 16, 2014, 09:20:22 PM: Quote from: hitech on January 16, 2014, 03:49:37 PM
Both, mostly C

Yay, C is my personal favorite language, C++ has too many exceptions IMO.
Title: Re: Is induced drag modeled in AH?
Post by: Arlo on January 16, 2014, 09:21:22 PM: Quote from: olds442 on January 16, 2014, 09:20:22 PM
Yay, C is my personal favorite language, C++ has too many exceptions IMO.

But it's a better grade. I can't even speak F.
Title: Re: Is induced drag modeled in AH?
Post by: hitech on January 16, 2014, 10:35:47 PM: Quote from: olds442 on January 16, 2014, 09:20:22 PM
Yay, C is my personal favorite language, C++ has too many exceptions IMO.

My view has been that C++ makes bad programers worse.

HiTech
Title: Re: Is induced drag modeled in AH?
Post by: mensa180 on January 18, 2014, 07:55:32 AM: Quote from: hitech on January 16, 2014, 10:35:47 PM
My view has been that C++ makes bad programers worse.

HiTech

I think Linus Torvalds has some rants you'd enjoy.
Title: Re: Is induced drag modeled in AH?
Post by: hitech on January 18, 2014, 11:46:41 AM: Quote from: mensa180 on January 18, 2014, 07:55:32 AM
I think Linus Torvalds has some rants you'd enjoy.

I went a read some of his stuff, and also the c++ guys counter to it. I did get a kick out his posts.
Btw I wrote my first code back in 1974 on a PDP8.
(http://trovar.com/pdp8e.jpg)
Of course my first programs were games (guess a number hi lo game) and next a navel battle game where you had to enter the elevation to shoot the other guys ship, and the computer would say xx yards short or long.

This is before the apple & trs80 had yet to be invented. My first Unix and C work professionally was in 1984.

I have used C++ code from guys who obviously have been around the block a long time, and they basically stayed away from all the pitfalls of people who think all data should be objects.

There are things I like very much about C++ building math library's with over loads is one of them. But I have seen far to many c++ code that including one piece of it, causes the headers to have to propagate threw your entire project. This is not really the languages fault, but simply the OO concept run a muck.

In the gaming side the biggest differences you can tell is on load times. If the game was designed by someone who has intimate knowledge of c & memory layouts , they can load huge pieces of data quickly. If some one goes off the deep end and think all items need to be objects with the ability to be overload. Load times can be measured in minutes.

HiTech
Title: Re: Is induced drag modeled in AH?
Post by: Arlo on January 18, 2014, 01:07:20 PM: Quote from: hitech on January 18, 2014, 11:46:41 AM
... a navel battle game where you had to enter the elevation to shoot the other guys ship, and the computer would say xx yards short or long.

Then you could add this to Aces High? :D
Title: Re: Is induced drag modeled in AH?
Post by: bozon on January 18, 2014, 02:59:14 PM: OK, here's a short test of induced drag and the power curve.

I measured the time-to-climb between 1000 and 4000 feet. For each plane I used the auto-climb set to the various IAS, starting from sea level, but taking time only starting from 1000 feet to let the speed settle. In all planes I used max power (WEP) except the Yak-3 that has none. The mean rate of climb is simply 3000 feet divided by time measured.

The auto-climb cloud not hold the yak at 110 mph, even though a player can hold it at speeds even slightly lower than 100 mph. So for the slowest speed in the Yak3 I just help it manually keeping the stall horn buzzing the whole time. The speed was slightly over 100, so I marked it at 105, but the climb time was probably longer than it could be because I was not fully stable and banked a little occasionally - the Yak climb angle is so steep that I see only skies in the front view...

Moss VI - 50% fuel, 170 rpg packege
190A8 - 25% fuel, 2*20mm package
Yak3 - 100% fuel

Here is the mean rate of climb:
(http://i40.tinypic.com/20zwih2.png)

And here is the rate of climb normalized to the rate at best climb speed:
(http://i41.tinypic.com/245mted.png)

The Yak-3 suffers very little energy loss due to induced drag on the back of the power curve. Even when flying with the stall buzzer yelling, it loses just a hair over 10% of its max climb rate (87%), while the climb rate of the Mossie and A8 plummets to 55% and 73% of their climb at best speed.

Whether or not this is true to reality, I still need to think about it - but I want to shoot at red icons, so I'll do the thinking later. However, these are the game facts and a confirmation to my feeling that the Yak-3 loses very little energy even when flying on the stall, while the mossie becomes a dump truck when flying on the back of the power curve.
Title: Re: Is induced drag modeled in AH?
Post by: hitech on January 18, 2014, 03:12:35 PM: bozon: The prop and HP will have a huge effect on these curves.

Bigger HP planes will typically drop off much move at slower speeds do to not being able to convert the HP into thrust.

HiTech
Title: Re: Is induced drag modeled in AH?
Post by: save on January 18, 2014, 05:18:51 PM: 25% of fuel in an A8 gives like 5-6 minutes of fuel on wep.

50% and 4*20mm is more representative for the A8 (base type of A8)
Title: Re: Is induced drag modeled in AH?
Post by: bozon on January 19, 2014, 03:27:48 AM: Quote from: hitech on January 18, 2014, 03:12:35 PM
bozon: The prop and HP will have a huge effect on these curves.

Bigger HP planes will typically drop off much move at slower speeds do to not being able to convert the HP into thrust.

HiTech
So its a prop efficiency effect? I thought props were at their peak efficiency at slow speeds and efficiency does not change that much between good props. If anything, the Yak-3 probably has the highest power loading of the three planes.

Anyway, now that I did the math I realize that there is more than prop efficiency effects. When looking at the ROC/ROC_peak as a function of IAS plot some of the math becomes a little simpler, but still too much to post here - the slope of the back of the power curve (i.e. the drop of the ROC below best climb speed) depends on the power loading with an additional dependency on the absolute mass ("power/mass^2" term in there) which is why the mossie "should" be doing so badly relative to the Yak3.

That still does not necessarily mean that the yak3 is OK - I don't have the numbers or the patience to calculate these graphs from theory, sorry. Maybe something is off with its "e" or "AR" parameters or too much engine power, IDK. It feels like one of those RedBull stunt planes, completely different from the other AH planes except the Spit16 perhaps. Not to mention that it takes as may hits as an F6F to bring down, while being a light, partially wooden, barely armored plane - but that is another topic.

Quote from: save on January 18, 2014, 05:18:51 PM
25% of fuel in an A8 gives like 5-6 minutes of fuel on wep.

50% and 4*20mm is more representative for the A8 (base type of A8)
Yes, but for the testing I feared that the A8 will not fly at 110 mph with a heavier loadout... :P
Title: Re: Is induced drag modeled in AH?
Post by: save on January 19, 2014, 09:36:41 AM: A normally loaded 190a8 have 105mph stall speed so you are way over :cool:
Title: Re: Is induced drag modeled in AH?
Post by: hitech on January 20, 2014, 10:31:32 AM: Quote from: bozon on January 19, 2014, 03:27:48 AM
So its a prop efficiency effect? I thought props were at their peak efficiency at slow speeds and efficiency does not change that much between good props. If anything, the Yak-3 probably has the highest power loading of the three planes.

As a general statement that is correct. But remember Efficiency = Thrust HP / Break HP.

Think about the fact that at very very slow speed I.E when you start rolling the prop efficiency is way less then 10 % and increases to its max efficiency normally around best climb speed. As a general statement best climb speed is a "slow speed". Using the same prop but adding HP will add top end, buy may do nothing for the climb rate.

The issue is that as the engines got bigger it became very difficult to make the props bigger, hence more blades or paddle blade was traded off to increase climb at the expense of top speed.

HiTech
Title: Re: Is induced drag modeled in AH?
Post by: Arlo on January 20, 2014, 11:41:34 AM: Thanks for being really into these details, HiTech. I never got the feeling the developers of other air combat sims/games really are. :salute :cheers: :)
Title: Re: Is induced drag modeled in AH?
Post by: Karnak on January 20, 2014, 11:57:57 AM: Quote from: Arlo on January 20, 2014, 11:41:34 AM
Thanks for being really into these details, HiTech. I never got the feeling the developers of other air combat sims/games really are. :salute :cheers: :)
Things like this are why I keep paying for an account that I rarely use.
Title: Re: Is induced drag modeled in AH?
Post by: bozon on January 20, 2014, 12:41:30 PM: Thanks for the info HT <S>
Title: Re: Is induced drag modeled in AH?
Post by: DaddyAce on January 21, 2014, 07:34:49 PM: Yes, thank you guys for the detail, clarification and respectful debate and clarification! Dale it is your dedication to realism that has kept my subscription current even when I go through long periods where I may do nothing more than occasionally browse the BBS! :salute
Title: Re: Is induced drag modeled in AH?
Post by: GhostCDB on September 06, 2014, 02:03:47 PM: This thread makes my head hurt. :bhead
Title: Re: Is induced drag modeled in AH?
Post by: Brooke on September 06, 2014, 04:20:33 PM: In the MA today, Skyyr was talking about how induced drag is not modeled in AH. That is false, and I said so. He told me that "even HT said that it wasn't modeled correctly." I said that I was skeptical of such a claim. He said to search around on his (Skyyr's) posts on the topic to verify that claim.

Well, here I am . . . again. Now that I see what topic we are in, I remember this topic and see that I have posted in it already several times.

AH *does* model induced drag correctly; and, no, HTC *did not* say otherwise.
Title: Re: Is induced drag modeled in AH?
Post by: Arlo on September 06, 2014, 05:40:53 PM: Was gonna give this thread a necro chiding but I see why it was given an add/bump. Sounds like Skyrr has a bad case of 'wanna believe I'm right no matter what' itis with a touch of 'so there.'

:lol
Title: Re: Is induced drag modeled in AH?
Post by: Skyyr on September 06, 2014, 07:16:53 PM: Quote from: Brooke on September 06, 2014, 04:20:33 PM
In the MA today, Skyyr was talking about how induced drag is not modeled in AH. That is false, and I said so. He told me that "even HT said that it wasn't modeled correctly." I said that I was skeptical of such a claim. He said to search around on his (Skyyr's) posts on the topic to verify that claim.

Well, here I am . . . again. Now that I see what topic we are in, I remember this topic and see that I have posted in it already several times.

AH *does* model induced drag correctly; and, no, HTC *did not* say otherwise.

Wrong thread. Let me find the other one.
Title: Re: Is induced drag modeled in AH?
Post by: Arlo on September 06, 2014, 10:38:48 PM: Quote from: Skyyr on September 06, 2014, 07:16:53 PM
Wrong thread. Let me find the other one.

Yes. Put your effort there.
Title: Re: Is induced drag modeled in AH?
Post by: FLS on September 06, 2014, 10:48:14 PM: I'm guessing it was HiTech's drag polar application comment.