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Ракеты в DCS


Chizh

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  • ED Team
7 hours ago, FAB999 said:

Э э эх, в одно время ,давным давно ,вы мне тут указывали что данные приведенный в книге Федосова есть истина ,а по его данным на высоте у Р-27ЭР МАКСИМАЛЬНАЯ дальность должна быть 40 км в ЗПС !

Можно получить дальность 40км в ЗПС если цель дозвуковая, а перехватчик летит под 2,5 М.

Единственный урок, который можно извлечь из истории, состоит в том, что люди не извлекают из истории никаких уроков. (С) Джордж Бернард Шоу

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Just tested to make 100% sure. The DCS R-27R behaves exactly like on this graph. Plus 150 m/s. But without extra provisions as the Su-35 pilot said it.
 

Spoiler

file.php?id=31394&t=1

21 hours ago, BlackPixxel said:

@Chizh

 

Could you run the rear aspect cases for 1, 5, and 10 km for R-27R and R-27T in the sim?

 

Would be interesting to see how the sim differes from their charts. This should help to get a better understanding of chart vs sim.


@ED Please check if the DLZ simulator underperforms relative to the R-27R graph. And R-73 one. Check if its consistently 10-15% at all altitudes.

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1 hour ago, Chizh said:

There is no 100% accurate and reliable information. Everything needs to be analyzed and check.


Function v-t in passive stage should be in logarithmic function form, simply by the physical rules. Same on east and on west. 
Should be in case of ballistic trajectory and as per my opinion in case of forced horizontal flight for such missiles as well. 
Here we see quite hard brakes of the speed between 8 and 12 seconds for 5 and 10km, also quite acceleration  between 10 and 20 seconds at 20km !!! 
Only trajectory at 15km is something close to true logarithmic function.


What is a reason…I’m still very sure that R-27ER in case of inertial radio-command sequence fly with gorka, it is for me indisputable, 100%. But still and also I’m not finding that gorka maneuvers would make such curving of logarithmic function v-t. 

Just as a thought, is it maybe that those v-t are for different altitudes fighter-target!? Two (5 and 10km) for target up and over, one from 20km for target down under and eventually 15km head to head.

 

Is it really that nobody of you doesn’t have someone close to Bauman to ask Denis as colleague to colleague or student (ex student) to professor…hey what hell this diagram presents. 

 

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15 часов назад, Chizh сказал:

Можно получить дальность 40км в ЗПС если цель дозвуковая, а перехватчик летит под 2,5 М.

Тогда в этих условиях не коррелируется дальность в ППС ;)  по Федосову 70 как то маловато ;)

…В бою не бывает чудес…

 

Мое видео виртуальных полетушек :

https://www.youtube.com/channel/UCWYN_xw4ZJAkJlCPwywW_Lg

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2 hours ago, FAB999 said:

Тогда в этих условиях не коррелируется дальность в ППС 😉 по Федосову 70 как то маловато 😉

А где у Федосова эта номограмма или таблица?

Единственный урок, который можно извлечь из истории, состоит в том, что люди не извлекают из истории никаких уроков. (С) Джордж Бернард Шоу

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  • ED Team

Тут без указания высоты пуска, скорости пуска и скорости цели ничего нельзя сказать.

Единственный урок, который можно извлечь из истории, состоит в том, что люди не извлекают из истории никаких уроков. (С) Джордж Бернард Шоу

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37 minutes ago, FAB999 said:

well, where is Table 3.2.2. Art. 284

 

 

 

L4JtR90.jpg

Unfortunately this table gets basic things wrong like number of missiles carried... so it is hard to trust deeper stats 😔

-------

All the people keep asking for capabilities to be modelled.... I want the limitations to be modelled.... limitations make for realistic simulation.

Arguing with an engineer is like wrestling with a pig in the mud, after a bit you realize the pig likes it.

 

Long time ago in galaxy far far away:

https://www.deviantart.com/alfafox/gallery

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On 6/24/2021 at 8:54 PM, Chizh said:

Because rear-hemisphere chart slightly incorrect. The DLZ simulator produces a more reasonable and smoother curve.

Fair enough, I would still prefere it matched or overmatched longest range rear scenario due to engineering overhangs and fusing, then current head-on... but acknowledge there is little or no data so it is your call. That 10-15% seams reasonable.

 

Also I know that there are bigger fish to fry in DCS currently 


Edited by FoxAlfa

-------

All the people keep asking for capabilities to be modelled.... I want the limitations to be modelled.... limitations make for realistic simulation.

Arguing with an engineer is like wrestling with a pig in the mud, after a bit you realize the pig likes it.

 

Long time ago in galaxy far far away:

https://www.deviantart.com/alfafox/gallery

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It shouldn't be difficult to do the math to see if the tail-aspect range makes sense.  The head-on range must be reached within a certain amount of time

In this case, if we take the 10km figure at 60km, we have 60 seconds to reach this range, we can assume we reach it in say 55, giving us some margin of error.

One can calculate the amount of distance the target aircraft flies in this time, and therefore the amount of distance that the missile flies as well.

The same time and distance is available for a tail-on intercept, although if the 150m/s overtake is desired, then the flight time should be reduced.   This will give you an idea of how well the rear aspect part of the graph fits, though it's really a ball-park calculation.

 

At low altitudes it gets trickier because we can no longer assume that we have the use of the full 60 seconds before the missile slows down to a useless speed.

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On 6/24/2021 at 5:46 AM, Chizh said:

First, it is not. At an altitude of 1 km in the forward hemisphere, the ranges are almost the same. Moreover, in side aspects, the simulator gives a great ranges.
Secondly, the nomogram does not correctly depict the dependence to the rear hemisphere. The curve should enter the abscissa axis along the normal, providing a smooth DLZ contour in the form of an ellipse. There should be no fractures. See red square on the drawing.

 

Screenshot 2021-06-24 083802.jpg

 

How do you think those charts were made?

 

Do they test fire on flanking targets and check the range, and then estimate straight line performance based on that?

 

Or would they rather test fire a straight line shot and then estimate the non-straight aspect angles based on that?

 

Why would you think that the non-straight aspects are correct in the chart but not the most simple straight shot one?

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R-27ER.jpg

 

Oh no, non-elliptical rear aspect. Chart is wrong.

 

R-27ER_range.jpg

 

What? another non-elliptical rear aspect. Chart is wrong.

 

1910889838_R-27Rrange-altitude.thumb.jpg

 

Again? This chart is also wrong!!!

 

 

R-73_ranges.gif.a7537b6436651198f58eb0a4

 

Damn, this one is also wrong.

 

 

R-27T_ranges.gif.e304562e934bc0e61e82342

 

This one too?? Russia WTF! all your charts are wrong!!!

 

What is more likely, 5 charts being wrong or Chizh being right?

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  • ED Team

You don't have to mention me once more.
As you can see, the curves on the R-73 are almost normal. The R-27 missiles have a strange curve. This error probably came from the hands of one developer.

Единственный урок, который можно извлечь из истории, состоит в том, что люди не извлекают из истории никаких уроков. (С) Джордж Бернард Шоу

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55 minutes ago, BlackPixxel said:

 

Look at the 1 km for the 73. Far from normal.

I agree. All these graphs are not drawn very neatly; it makes no sense to use this for accurate measurements.

Единственный урок, который можно извлечь из истории, состоит в том, что люди не извлекают из истории никаких уроков. (С) Джордж Бернард Шоу

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«При атаке на попутно-пересекающихся курсах для обнаружения цели необходимо выдерживать скорость сближения истребителя с целью не менее 50 км/ч на дальности менее 15 км и не менее 150 км/ч на дальности более 15 км»

 

This is from «Боевое применение самолета Миг-29»

 

I’ve done several kinematic models for R-27ER, increased nominal Cx, reduced nominal Cx, several functions for Cy, several functions for converting angle of attack into delta Cx or induced Cx…etc and etc.

And always shooting in ZPS at 5km makes results significantly different to diagram. While at 10km and 1km in both PPS and ZPS and 5km in PPS results can be considered as fairly matched, only ZPS at 5km gives head scratching.

 

With this sentence from beginning, is it fair to consider that for R-27ER distance of 15km in ZPS also can be with some unique recommendations. I think so.

You may see that curving in ZPS diagram of R-27R is kind of uniformed. All distances under 15km.

In diagram of ZPS of R-27ER curving is kind of uniformed for group under 15km and also uniformed over 15km but in different form. 
 

For me is not a problem to accept that there are many other inputs to understand diagrams correctly. We don’t have those additional notes…what if beyond this diagram also there are notes, in case distance in over 15km make extra speed 200 or 250 or 300 km/h to match…

 

Diagrams if they are from official military manuals have to be considered as valid, eventually with slight incorrectness but not crucially wrong. It is about us which don’t  understand it fully.

 

 


Edited by tavarish palkovnik
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14 minutes ago, Chizh said:

I agree. All these graphs are not drawn very neatly; it makes no sense to use this for accurate measurements.

 But would it not be so that the ranges for 0° and 180° are the most accurate, and everything in between is "interpolated" by hand?

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1 час назад, Chizh сказал:

I agree. All these graphs are not drawn very neatly; it makes no sense to use this for accurate measurements.

А вы могли бы примерно показать, как должен выглядеть правильный график?

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3 hours ago, Chizh said:

I agree. All these graphs are not drawn very neatly; it makes no sense to use this for accurate measurements.

Complety agree, it is since they are not aero charts, but pilot guidelines.

 

Aero should perform at or above level, that is why adjstment is maybe needed just to have all points in range and call it a day.


Edited by FoxAlfa
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-------

All the people keep asking for capabilities to be modelled.... I want the limitations to be modelled.... limitations make for realistic simulation.

Arguing with an engineer is like wrestling with a pig in the mud, after a bit you realize the pig likes it.

 

Long time ago in galaxy far far away:

https://www.deviantart.com/alfafox/gallery

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I am sorry but I really don't understand, there are numerous charts which all show the same thing, same DLZ shapes.... for multiple missiles, both Russian and NATO. They also clearly demonstrate within reasonable common logic that the ER is still missing some performance in rear aspect at 1km alt.

 

These charts are the best information we have about these missiles, hence I don't understand why ED is making speculative adjustments that don't match the charts to intentionally tune the missile down, with the excuse now being "they must be not accurate, hand drawn, because.... we dont know 🤣"? So the big question is where are the accurate charts then?

 

What logic is this?! Just match the charts and be done with it. There is a small percentile that needs to match here. Probably a 10% or less of adjustment.

 

Is ED that afraid of BLUEFOR salt if ER is actually correctly modelled kinematically?

 

Just seems a bit odd to me, maybe I'm reading into it too much... 

 

 

 

 

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3 hours ago, Breakshot said:

These charts are the best information we have about these missiles, hence I don't understand why ED is making speculative adjustments that don't match the charts to intentionally tune the missile down, with the excuse now being "they must be not accurate, hand drawn, because.... we dont know 🤣"? So the big question is where are the accurate charts then?

Well they ran CFD on the missile and implemented it it not matching the chart isn't their fault and indicates that the chart may be wrong.

3 hours ago, Breakshot said:

What logic is this?! Just match the charts and be done with it. There is a small percentile that needs to match here. Probably a 10% or less of adjustment.

The charts may be unreliable.  But you can't just change the fly out performance in one regime and not have it also affect all the others where the missile is more or less matching the chart.

3 hours ago, Breakshot said:

Is ED that afraid of BLUEFOR salt if ER is actually correctly modelled kinematically?

Probably not

 

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41 minutes ago, nighthawk2174 said:

Well they ran CFD on the missile and implemented it it not matching the chart isn't their fault and indicates that the chart may be wrong.


The R-27R matches the chart by 100%. No deviations whatsoever. The 27R and 27ER got entirely different drag changes.

The new rocket motor distribution also reduced the range against targets at under 15.000 feet. On top of making the missile easier to defeat at NEZ.

Are the shapes of R-27R and R-27ER that different? Were the old drag differences between the two too small? Did the R-27ER get a high supersonic drag decrease, but not R-27R? If yes, why?


Edited by Max1mus
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9 hours ago, Max1mus said:

Are the shapes of R-27R and R-27ER that different?

 

As far as a Cd0 graph is concerned, very possibly yes.  It's an entire graph, not just 'a number' but a different number at each point.   The overall shape could show all sort of things, like a narrower or extended peak, different slope, etc.

Without at least doing a CFD, claiming that R-27R and R-27ER have a similar drag is reasonable only because you don't have time/resources to run the CFD.   

[sIGPIC][/sIGPIC]

Reminder: SAM = Speed Bump :D

I used to play flight sims like you, but then I took a slammer to the knee - Yoda

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