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FM/DM threads Everything about FM/DM in CoD

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  #1  
Old 01-24-2012, 10:28 PM
Bewolf Bewolf is offline
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Default Roll Rate and Mass

JUst wanted to ask, Il2 had two serious problems that negated some aircrafts actual strengh and weaknesses. That was roll rate and mass. For example the FW190 was never really able to play out one of it's main historic strenghs, it's roll rate, giving it such maneuverability.

In Cod that problem appears to be solved, considering that the 109 has a much better roll rate then the Spritfire, which in a close in dogfight negates a lot of the Spits turning advantages and thus even makes dealing with the Spit II fairly easy, given you know what you do. But what about mass? did anybody make any tests yet in this regard, zoom climb abilities and such?
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  #2  
Old 01-24-2012, 11:11 PM
ACE-OF-ACES ACE-OF-ACES is offline
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What lead you to belive that IL-2's 6DOF does not take mass into account?
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Old 01-25-2012, 05:09 AM
jf1981 jf1981 is offline
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Hi

In my opinion they are adding a lot of things to the sim e.g. rads fully open won't affect drag. I'm not surprised if other secondary effects appear later on.
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Old 01-25-2012, 07:04 AM
Robo. Robo. is offline
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Originally Posted by Bewolf View Post
For example the FW190 was never really able to play out one of it's main historic strenghs, it's roll rate, giving it such maneuverability.
Hi Bewolf, Fw 190's roll rate in Il-2 is phenomenal dude, what exactly do you mean.
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Old 01-25-2012, 02:25 PM
ACE-OF-ACES ACE-OF-ACES is offline
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Originally Posted by Robo. View Post
Hi Bewolf, Fw 190's roll rate in Il-2 is phenomenal dude, what exactly do you mean.
I tested several of the IL-2 roll rates years ago.. and compared them to that NACA document that had several roll rates listed for several planes.. I forget the doc number.. But it had the Fw190, P39, zero, P38, and a few more.

What I found was most of the roll rate curves had the righ shape.. but the peeks were quite different, and, occured at quite different speeds. In the Fw190 case, it's peek occured at a much lower speed than the real Fw190 and the peek value was a bit larger.

Basically the curve was shifted LEFT wrt speed and UP wrt ROLL RATE

What sucks for the 190 is it's peek happens at a much lower speed, so the 'classical' tatics will not work like they should.. That is to say the Fw190 was a true TnB figher.. but because it's peek roll rate is shifted down to a much lower speed you can not make use of the great roll rate at the higher speeds tatics wise.

Each plane I tested has simular effect.. But it has been so long I don't recall what they were, the 190 results did stick out in my mind so I remember them

In laymans terms.. The ingame Fw190 roll rate is 'twitchy' at low speeds with regards to roll rate.. Almost too fast.. but at higher speeds the roll rate is much lower than it should be which means you can not apply the 'classical' roll rate tatics used by real 190 pilots
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Old 01-25-2012, 06:51 PM
Bewolf Bewolf is offline
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Originally Posted by ACE-OF-ACES View Post
What lead you to belive that IL-2's 6DOF does not take mass into account?
6DOF?

It's been years since the debate was raging, but the consensus back then was that Mass in IL2 was not taken propperly into account (Means, if you switched of engine, most airplanes, coming from the same speed, climbed to roughly the same altitude), which kinda nerfed planes like the P47
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Old 01-25-2012, 08:13 PM
Kurfürst Kurfürst is offline
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Quote:
Originally Posted by Bewolf View Post
6DOF?

It's been years since the debate was raging, but the consensus back then was that Mass in IL2 was not taken propperly into account (Means, if you switched of engine, most airplanes, coming from the same speed, climbed to roughly the same altitude), which kinda nerfed planes like the P47
Given the results of RL comparative tests I've seen, I do not believe its just a matter of mass. More like its a complex interaction between drag, mass and thrust, as it should be. Mass by nature pulls the plane down, not up.

What does help however that energy is a function of mass and velocity, so a high speed heavy aircraft stores a lot of energy. However, as it travels up,

The zoom performance is thus essentially the relation of mass and starting velocity, and drag & stall characteristics of the aircraft; drag will define how quickly the aircraft will loose that velocity (and thus energy, since mass is constant), and stall speed when this velocity loss will become critical, and when the aircraft will stop ascending.

Power to weight (thrust pulling the aircraft up, mass pulling it down) ratio will also gain important fuction at the top of the zoom, and here mass is actually detrimental.

Bottomline, while mass is important, drag characteristics are equally important, put two and two together, and the deciding airframe related factor is equivalent flat plate / mass ratio. Ideally, you want a relatively heavy plane (for its size) with a low absolute drag and powerful thrust.

Dunno, I may have got the whole thing wrong, just wondering about the factors. Thing is however, that analouges to empirical knowledge such as that heavier gun shots, ball shaped objects ie. fired by the same force etc. fly further do not apply here, since different aircraft have additional properties: a) ever present thrust (engine, they do not work with a given, identical starting force) b) different shapes and drag.
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Old 01-25-2012, 10:13 PM
ACE-OF-ACES ACE-OF-ACES is offline
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Quote:
Originally Posted by Bewolf View Post
6DOF?
Six Degrees of Freedom Flight Model

Quote:
Originally Posted by Bewolf View Post
It's been years since the debate was raging, but the consensus back then was that Mass in IL2 was not taken propperly into account (Means, if you switched of engine, most airplanes, coming from the same speed, climbed to roughly the same altitude), which kinda nerfed planes like the P47
Well general consensus can be over rated IMHO!

But based on the total mechanical energy testing I did years ago, each plane had a very different result. I still have a copy of those test results that I plan on uploading to my website, i.e.

www.flightsimtesting.com

But they are not up at the moment.
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  #9  
Old 01-25-2012, 10:58 PM
Crumpp Crumpp is offline
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Here is a good paper on energy use in Aircraft.

http://web.mit.edu/aeroastro/people/...tEnergyUse.pdf
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  #10  
Old 01-26-2012, 04:05 AM
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CaptainDoggles CaptainDoggles is offline
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Quote:
Originally Posted by Bewolf View Post
6DOF?
It means 6 degrees of freedom. In terms of a flight simulation/model, it means that the model takes into account all 6 degrees of freedom (yaw, pitch, roll, forward/back motion, up/down motion, and left/right motion).

Pretty redundant term, honestly.
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