Aces High Bulletin Board

General Forums => Aces High General Discussion => Topic started by: Skyyr on May 07, 2014, 02:33:13 PM

Title: Drag modeling - what was changed?
Post by: Skyyr on May 07, 2014, 02:33:13 PM
A few of us were discussing various aircraft and this thread came up:
http://bbs.hitechcreations.com/smf/index.php/topic,185075.msg2330612.html#msg2330612

There are several references to the "drag model" being updated. What was changed, exactly? Is this is a mistake? Or was it actually updated?
Title: Re: Drag modeling - what was changed?
Post by: craz07 on May 07, 2014, 03:20:15 PM
See Rules #2, #4
Title: Re: Drag modeling - what was changed?
Post by: Lusche on May 07, 2014, 03:24:16 PM
There are several references to the "drag model" being updated. What was changed, exactly? Is this is a mistake? Or was it actually updated?


It refers to the a global flight model update in 2006. Can't remember any technical details at the moment though...
Title: Re: Drag modeling - what was changed?
Post by: Skyyr on May 07, 2014, 03:39:10 PM
See rule #4
Title: Re: Drag modeling - what was changed?
Post by: hitech on May 07, 2014, 03:42:02 PM
We changed methodology to better fit drag curves overt the entire flight envelope.
The net effect was less induced drag.

Beyond that , I will not elaborate on the specifics.

HiTech
Title: Re: Drag modeling - what was changed?
Post by: Karnak on May 07, 2014, 04:00:10 PM

It refers to the a global flight model update in 2006. Can't remember any technical details at the moment though...
Pretty sure it refers to the change that happened in 2000. Version 1.04 IIRC.
Title: Re: Drag modeling - what was changed?
Post by: Skyyr on May 07, 2014, 04:01:43 PM
We changed methodology to better fit drag curves overt the entire flight envelope.
The net effect was less induced drag.

Beyond that , I will not elaborate on the specifics.

HiTech

If I may ask (without specifics), was the effect of less induced drag due to a redistribution of the curves? Or was it simply adjusted as needed, in specific ranges of flight envelopes?
Title: Re: Drag modeling - what was changed?
Post by: kappa on May 07, 2014, 04:02:31 PM
I believe the 190a5 should have the same drag characteristics as 7.62x54rd... If that is not acceptable,  I'm good with matching it to a 5.56rd.. thx
Title: Re: Drag modeling - what was changed?
Post by: Vraciu on May 07, 2014, 04:14:07 PM
I believe the 190a5 should have the same drag characteristics as 7.62x54rd... If that is not acceptable,  I'm good with matching it to a 5.56rd.. thx

That was very helpful.  Thanks.
Title: Re: Drag modeling - what was changed?
Post by: Changeup on May 07, 2014, 05:02:06 PM
I believe the 190a5 should have the same drag characteristics as 7.62x54rd... If that is not acceptable,  I'm good with matching it to a 5.56rd.. thx

I'd prefer the drag curve over the entire flight envelope to be .14X.222.  I win.
Title: Re: Drag modeling - what was changed?
Post by: Wiley on May 07, 2014, 05:33:38 PM
If I may ask (without specifics), was the effect of less induced drag due to a redistribution of the curves? Or was it simply adjusted as needed, in specific ranges of flight envelopes?

Just curious.  It was changed 8 years ago, what does it matter?

Wiley.
Title: Re: Drag modeling - what was changed?
Post by: Vraciu on May 07, 2014, 06:24:17 PM
Just curious.  It was changed 8 years ago, what does it matter?

Wiley.

Curiosity would seem to be enough.   Comparing.   
Title: Re: Drag modeling - what was changed?
Post by: GScholz on May 07, 2014, 07:05:40 PM
We changed methodology to better fit drag curves overt the entire flight envelope.
The net effect was less induced drag.

Beyond that , I will not elaborate on the specifics.

HiTech

Sounds more like an increase in simulation fidelity, not a "change" per se. Every time fidelity/resolution is improved the end result will differ slightly from previous, less accurate results.
Title: Re: Drag modeling - what was changed?
Post by: Vraciu on May 07, 2014, 07:08:38 PM
Sounds more like an increase in simulation fidelity, not a "change" per se. Every time fidelity/resolution is improved the end result will differ slightly from previous, less accurate results.


Hypothetically speaking...  If induced drag is modeled improperly by a greater proportion, how is that an improvement?
Title: Re: Drag modeling - what was changed?
Post by: GScholz on May 07, 2014, 07:20:01 PM
Let's not speak hypothetically. If you have a specific issue or grievance, voice it. Don't dance around it with "hypothetical".
Title: Re: Drag modeling - what was changed?
Post by: Changeup on May 07, 2014, 07:28:28 PM
See rule 4
Title: Re: Drag modeling - what was changed?
Post by: Karnak on May 07, 2014, 07:31:57 PM

Hypothetically speaking...  If induced drag is modeled improperly by a greater proportion, how is that an improvement?
It was demonstrated that induced drag was too high.  HTC fixed that, but nobody, including HTC, claims that AH is perfect.  If you think otherwise about induced drag in AH it is all on you to support that claim.

In other words, put up or **** up.
Title: Re: Drag modeling - what was changed?
Post by: Changeup on May 07, 2014, 07:34:43 PM
See rule 4
Title: Re: Drag modeling - what was changed?
Post by: Vraciu on May 07, 2014, 07:44:21 PM
Let's not speak hypothetically. If you have a specific issue or grievance, voice it. Don't dance around it with "hypothetical".


 :rofl
Title: Re: Drag modeling - what was changed?
Post by: VonMessa on May 07, 2014, 07:48:40 PM
See Rule #2
Title: Re: Drag modeling - what was changed?
Post by: Changeup on May 07, 2014, 07:55:57 PM
See Rule #2
Title: Re: Drag modeling - what was changed?
Post by: BaDkaRmA158Th on May 07, 2014, 08:12:08 PM
If i am correct, the changes mostly effected the aircraft in the areas of drop tanks,rocket rails and bomb equipment. Even if the Aircraft itself doesn't model the code by eye candy, the effect* is still there. As in, even loading a bomb or DT will "add" that component to the plane, as in increased drag on the drop tank,and rails..as well as weight. Without or without the component being dropped, even if you drop your DT, even having the shakles for it ad's drag and weight. how much? test and find out. ;)


I found my P39Q without .50 gondolas & Dt removed can get better range with constant engine management "and better speed" then it ever could with the DT. Figure that math out.


If i remember the it correctly.  :rock
Title: Re: Drag modeling - what was changed?
Post by: PJ_Godzilla on May 07, 2014, 09:16:08 PM
See Rule #2
Title: Re: Drag modeling - what was changed?
Post by: Skyyr on May 07, 2014, 10:49:51 PM
Just curious.  It was changed 8 years ago, what does it matter?

Wiley.

Because of this thread:
http://bbs.hitechcreations.com/smf/index.php/topic,358107.0.html

It was mentioned that the actual formula for induced drag was used as the direct code for drag modeling, yet it was mentioned above that "curves" were adjusted. Obviously, you can't have both and have it be 100% accurate, so there is some intermediate modeling going on. My question was what is that modeling and by how much is it adjusted.
Title: Re: Drag modeling - what was changed?
Post by: Changeup on May 07, 2014, 11:29:11 PM
Because of this thread:
http://bbs.hitechcreations.com/smf/index.php/topic,358107.0.html

It was mentioned that the actual formula for induced drag was used as the direct code for drag modeling, yet it was mentioned above that "curves" were adjusted. Obviously, you can't have both and have it be 100% accurate, so there is some intermediate modeling going on. My question was what is that modeling and by how much is it adjusted.

Now I'm curious.  Knowing this will help you how?  Or are you just wondering about the finer points of flight modeling?
Title: Re: Drag modeling - what was changed?
Post by: Skyyr on May 07, 2014, 11:30:17 PM
Now I'm curious.  Knowing this will help you how?  Or are you just wondering about the finer points of flight modeling?

Call it curiosity at this point.
Title: Re: Drag modeling - what was changed?
Post by: VonMessa on May 08, 2014, 05:22:29 AM
Call it curiosity at this point.

(http://i239.photobucket.com/albums/ff107/tymekeepyr/funny-curiosity-killed-cat-head-in-pinata-pics_zpsbafb70a0.jpg) (http://s239.photobucket.com/user/tymekeepyr/media/funny-curiosity-killed-cat-head-in-pinata-pics_zpsbafb70a0.jpg.html)
Title: Re: Drag modeling - what was changed?
Post by: danny76 on May 08, 2014, 05:26:04 AM
See Rule #2
Title: Re: Drag modeling - what was changed?
Post by: LCADolby on May 08, 2014, 06:43:51 AM
There's a picture of the numbers over a F4U's wing showing the modelling, sadly I don't have it, but I'm sure that picture that exists would help this discussion if anyone has it.
Title: Re: Drag modeling - what was changed?
Post by: FLOOB on May 08, 2014, 07:37:06 AM
Call it curiosity at this point.
He says in a thread about drag models.
Title: Re: Drag modeling - what was changed?
Post by: MrRiplEy[H] on May 08, 2014, 08:16:22 AM
See rule #2
Title: Re: Drag modeling - what was changed?
Post by: hitech on May 08, 2014, 09:46:00 AM
Call it curiosity at this point.

As I said in my response, I am not speaking any more about the details of how we do modeling.

HiTech
Title: Re: Drag modeling - what was changed?
Post by: SmokinLoon on May 08, 2014, 01:52:33 PM
See rule #2
Title: Re: Drag modeling - what was changed?
Post by: Ack-Ack on May 08, 2014, 02:08:02 PM
As I said in my response, I am not speaking any more about the details of how we do modeling.

HiTech

Without going into specific detail about the drag modeling, could you explain the difference between the old drag model and the updated one?

ack-ack
Title: Re: Drag modeling - what was changed?
Post by: MrRiplEy[H] on May 08, 2014, 02:12:32 PM
See rule #2

Title: Re: Drag modeling - what was changed?
Post by: PJ_Godzilla on May 08, 2014, 03:10:18 PM
Strange thread... I will say no more, other than: the modeling is closely guarded and it looks like people need to respect that.

So, Skuzzy, why don't you just put this one out of its misery - and I'm not tryin gto back-seat moderate, just asking?
Title: Re: Drag modeling - what was changed?
Post by: hitech on May 08, 2014, 03:15:46 PM
Without going into specific detail about the drag modeling, could you explain the difference between the old drag model and the updated one?

ack-ack

Sorry I can not Ack Ack, a lot of how we do modeling is fairly unique, and I treat it as a trade secret.

HiTech