Ракеты в DCS

[nighthawk2174]

Is the 150m/s closure rate backed up by any other sources beyond the one picture that i've seen posted?

[Chizh]

8 hours ago, BlackPixxel said:

In all rear hemisphere cases (1 km, 5 km, 10 km) the DLZ sim shows 15% less than the chart, so we can assume that the DLZ has some extra safety margin.

 

The "errors" in the hand drawing of the chart can not result in the missiles having consistenty 15% more range in the chart than in the sim, in all three altitudes.

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.

 

[dundun92]

So your saying every DLZ out there for literally every other missile is wrong because its not a perfect ellipse??? Heres 2 examples for the AIM-7

 

(Solid black line is Rmax)

You mean to tell me both the RuAF and the USAF dont know how to draw diagrams for their own militaries?

Edited June 24, 2021 by dundun92

[BlackPixxel]

5 hours ago, 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.

 

 

Don't you read what I am writing??

 

I am saying 15% less in REAR HEMISHPERE. Which is what the HUD photo was about...

 

EVERY SINGLE range chart of the russian missiles shows a curve that is not elliptical at the right side. So they are all wrong?

To bad Chizh was not working for Vympel back then, otherwise they would have found this error.

Edited June 24, 2021 by BlackPixxel

[BlackPixxel]

And why must it be that your ellipse results in less overall range? Why must it always underperform?

Because russian missile bad?

Why do you never come to the idea that the ellipse could look like this:

 

[GGTharos]

9 hours ago, dundun92 said:

So your saying every DLZ out there for literally every other missile is wrong because its not a perfect ellipse??? Heres 2 examples for the AIM-7

 

 

 

But if you do the basic math on that range you find that it immediately makes no sense.

 

9 hours ago, dundun92 said:

(Solid black line is Rmax)

You mean to tell me both the RuAF and the USAF dont know how to draw diagrams for their own militaries?

 

But you should also say what the dashed line is as well ... this is very important wrt this graph, and shows how DLZs can also be inaccurate.

[dundun92]

3 hours ago, GGTharos said:

But you should also say what the dashed line is as well ... this is very important wrt this graph, and shows how DLZs can also be inaccurate.

Dashed line is the F-4 WCS DLZ, so not really relevant, the solid line is the actual kinetic performance

[GGTharos]

It's very relevant.  It's a computed DLZ that doesn't match the physics of the missile.

And everyone here is adamant that the DLZs must be perfect and correct.  We have no data on the actual flight characteristics of the missile itself.  There's only one missile that we have this for, and that's the AIM-9L.

 

Further, this is the TACMAN for the F-4 - these kinds of graphs for modern weapons, with this kind of detail are nowhere to be found.  The graphs we have from the Su-27 and MiG-29 manuals are great, but not invulnerable to further scrutiny - they're not 'vault' material.

Edited June 24, 2021 by GGTharos

[Chizh]

13 hours ago, dundun92 said:

So your saying every DLZ out there for literally every other missile is wrong because its not a perfect ellipse??? Heres 2 examples for the AIM-7

 

(Solid black line is Rmax)

You mean to tell me both the RuAF and the USAF dont know how to draw diagrams for their own militaries?

 

I did not say that there is an ideal ellipse, on the contrary, there is rather an egg-shaped contour. But note that there are no fractures in your charts and this is correct.

[Max1mus]

What is the "maximum fighter speed" in this document?

Edited June 24, 2021 by Max1mus

[Chizh]

8 hours ago, BlackPixxel said:

 

Don't you read what I am writing??

 

I am saying 15% less in REAR HEMISHPERE. Which is what the HUD photo was about...

 

EVERY SINGLE range chart of the russian missiles shows a curve that is not elliptical at the right side. So they are all wrong?

To bad Chizh was not working for Vympel back then, otherwise they would have found this error.

 

What does Vympel have to do with it? We are looking at charts that have obvious errors.
You seem to be trying not to see the obvious.

[Max1mus]

2 minutes ago, Chizh said:

What does Vympel have to do with it? We are looking at charts that have obvious errors.
You seem to be trying not to see the obvious.

Do the R-27R charts have errors?

Speaking of which, can someone re-post the original, "hand drawn" one here?

Edited June 24, 2021 by Max1mus

[nighthawk2174]

Something that keeps coming to mind for me, the chart that keeps getting referenced in terms of the 150m/s needed closure rate being the limiting factor on its R-max circles (probable hand drawn errors aside).  Is it at all confirmed that it does take this into account? Or is it just a raw look at the kinematics?

[FoxAlfa]

Currently DCS missiles matches the chart on head-on and fall a bit (10-15%) short on tail-on.

Can we just make sure that charts match or excide the rear aspect shot and give it a rest since we all agree that tail-on is more valid shot?

Edited June 24, 2021 by FoxAlfa

[BlackPixxel]

28 minutes ago, Chizh said:

What does Vympel have to do with it? We are looking at charts that have obvious errors.
You seem to be trying not to see the obvious.

 

Every single chart of R-27R, R-27T, R-27ER (both charts) and R-73 has this "error".

 

So they are all wrong, lol.

Edited June 24, 2021 by BlackPixxel

[Chizh]

28 minutes ago, BlackPixxel said:

 

Every single chart of R-27R, R-27T, R-27ER (both charts) and R-73 has this "error".

 

So they are all wrong, lol.

 

In other missiles, this fracture is less pronounced.
Yes, this is incorrect diagram contour. It’s strange that you don’t realize it.

 

38 minutes ago, FoxAlfa said:

Currently DCS missiles matches the chart on head-on and fall a bit (10-15%) short on tail-on.

 

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

[BlackPixxel]

@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.

[GGTharos]

1 hour ago, Max1mus said:

What is the "maximum fighter speed" in this document? I tested at the maximum speed achievable in the MiG-29 with missiles and no fuel tank at 15km of altitude. That was Mach 2.2+. After 40s, the missile was at 1150 m/s, under the red dot even.
2.7_ER_underperform_15000m.trk

 

Maybe I'm missing something, but if you ran this test at 15000m, then the missile is over-performing.  Unless the red marks are not yours, but, 1150m/s at 40 sec ... is over-performing.  That graph has somewhat suspiciously neat peaks coinciding with nice round numbers as well.  Empirical graphs that I have seen aren't quite that neat, although it really is only the peaks.

 

In any case, even if you don't know the 'maximum fighter speed' you don't need it:  Use any given speed, check the missile's peak speed and then adjust launch speed up/down until the missile matches the desired peak speed.  Then collect data after motor burn-out.

Edited June 24, 2021 by GGTharos

[GGTharos]

1 hour ago, Max1mus said:

What is the "maximum fighter speed" in this document? I tested at the maximum speed achievable in the MiG-29 with missiles and no fuel tank at 15km of altitude. That was Mach 2.2+. After 40s, the missile was at 1150 m/s, under the red dot even.
2.7_ER_underperform_15000m.trk

 

 

@Chizh is this time-speed chart considered to be accurate, reliable information by you/ED?

[Max1mus]

1 hour ago, GGTharos said:

Maybe I'm missing something, but if you ran this test at 15000m, then the missile is over-performing.  Unless the red marks are not yours, but, 1150m/s at 40 sec ... is over-performing.  That graph has somewhat suspiciously neat peaks coinciding with nice round numbers as well.

 

Looks like i made a mistake, i mixed up the 15km/20km lines. The red dots are not mine, Chizh posted this a while ago, before the low altitude range reduction and high altitude tange increase in 2.7.

 

Different question: Since R-27R and R-27ER have nearly identical bodies, should the drag not be almost the same? By my understanding, the recent patch gave R-27R an overall drag reduction where as R-27ER got the drag changes in entirely different areas. Shouldnt the same drag changes be applied to both missiles?

[GGTharos]

The R-27ER has a diameter change in the middle of its body.  I don't know what the full effect would look like, but 'more drag' is the correct answer.  I just couldn't tell you how much more.

[TotenDead]

Вопрос. По маневренности Р-77 и аим-120В сейчас одинаковы? Учитывается ли, что решетчатые рули позволяют получать плавное обтекание до углов атаки в 40-50 градусов?

[FAB999]

13 часов назад, Chizh сказал:

...

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

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 !

 

сейчас вы мне тут приводите график якобы с неправильными кривыми и говорите что он дескать завышен на 15-20% по ЗПС ,то есть в ЗПС на высоте более 10 км для Р-27ЭР уже и дальность в 30 км недосягаема !

 

? ? ?  

 

PS 

хотя 27ЭР самая энерговооруженная в своем семействе 

[tavarish palkovnik]

 

 

Расчет границы гарантированной зоны возможного пуска.pdf

 

 

[Chizh]

20 hours ago, GGTharos said:

 

@Chizh is this time-speed chart considered to be accurate, reliable information by you/ED?

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