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Ракеты в DCS


Chizh

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5 hours ago, BlackPixxel said:

 

You don't seem to understand.

 

Your SUV-27 simulation always shows the range with around 15 % less than the kinematic range of the missile, as safety margin.

Your SUV-27 simulation shows 7.95 km for 1 km.

Add 15%, and you end up with around 9.14 km of range. Pretty much the value of the chart.

 

Do you want to say now that the DLZ simulation also has the error in it? Was the code for that software hand drawn as well?

 

But let's look at the flyout chart.

I made it square to be easier to work with, and marked the flyout distance of the missile at 1100 km/h, which is at 306 m/s.

It is slightly short of 10 km. If we now factor in the minimum closure speed for the proximity fuze to work (150 m/s), then it is no suprise that the launch range chart shows a little less.

There is nothing to argue here, you have now seen from three different sources that the R-27ER flies quite far at 1100 km/h and 1 km of altitude. And this is how it should perform in DCS as well.

image.png

 

It is not worth measuring the range along these strongly oblique charts. Their accuracy is even less than that of circulars.

As you known SUV-27 simulation shows 7.95 km for 1 km.

 

We have done a preliminary CFD research of the R-27ER. It turned out that in the game missile has less drag than the research shows.

Therefore, we will not change anything yet.

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13 minutes ago, Chizh said:

It is not worth measuring the range along these strongly oblique charts. Their accuracy is even less than that of circulars.

As you known SUV-27 simulation shows 7.95 km for 1 km.

 

We have done a preliminary CFD research of the R-27ER. It turned out that in the game missile has less drag than the research shows.

Therefore, we will not change anything yet.

I don't understand how you can say the data is inaccurate when it is official data. Are you denying official data because you "think" it is wrong now? How many times have you told other users in this thread that what they think does not matter, and that they need to provide official data. Yet, when we provide official data you think is wrong because it is hand drawn? 

How can you argue against the facts? That is irrational, illogical, and asinine even, Chizh. 

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18 minutes ago, Chizh said:

We have done a preliminary CFD research of the R-27ER. It turned out that in the game missile has less drag than the research shows.

Therefore, we will not change anything yet.

 

Well, then either your CFD is bad or you have to increase the thrust of the motor.

Because it has to reach the ranges specified in the charts.

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6 minutes ago, BlackPixxel said:

 

Well, then either your CFD is bad or you have to increase the thrust of the motor.

Because it has to reach the ranges specified in the charts.

Our missiles mostly matches the charts. But the problem is that the charts themselves are not very accurate.

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5 minutes ago, Chizh said:

Our missiles mostly matches the charts. But the problem is that the charts themselves are not very accurate.

Who said the charts are not accurate? Do you work at Vympel and can tell us with absolute authority that the charts are wrong?

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4 minutes ago, Jack1nthecrack said:

Who said the charts are not accurate? Do you work at Vympel and can tell us with absolute authority that the charts are wrong?

Above, I have already shown the incorrectness.

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46 минут назад, Chizh сказал:

We have done a preliminary CFD research of the R-27ER. It turned out that in the game missile has less drag than the research shows.

Therefore, we will not change anything yet.

Опять -5, 15  процентов не в пользу Ред Тим)) Когда были произведены предварительные продувки р27эр? Что они ещё показали? Р27ЭР ещё медленнее должна быть)? Не проверяли  р77?

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33 minutes ago, Hoarfrost said:

Опять -5, 15  процентов не в пользу Ред Тим)) Когда были произведены предварительные продувки р27эр? Что они ещё показали? Р27ЭР ещё медленнее должна быть)? Не проверяли  р77?

Р-77 пока не проверяли.

Р-27ЭР продули, оказалось что ее сопротивление больше чем в игре. Пока в раздумьях. Будем уточнять геометрию модели, потом повторим. Но с большой вероятностью из Р-27ЭР выжать больше ничего не получится.

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Я не смотрю телевизор

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1 hour ago, Chizh said:

The R-27ER was blown through, it turned out that its resistance was greater than in the game. While in thought. We will refine the geometry of the model, then repeat it. But with a high probability, nothing else will be squeezed out of the R-27ER.

 

Could it be the difference between 3 sec burn at with a weaker sustain as in DCS instead of 2 sec burn with stronger sustain as in some tables that is causing the difference? 


The 2 sec burn would increase the range but reduce the speed, better long-range config in my opinion, R-27R should be for a closer range anyway. 

Current DCS config (if I am getting the math right) is 3sec at 7500kg and then 7sec at 1480kg vs 2sec at 7500kg and then 8sec at 2238kg. 
The energy sum is the same. 

sootvetstvuet_li_semejstvo_r27_1.jpg

 


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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1 час назад, Chizh сказал:

Р-77 пока не проверяли.

Р-27ЭР продули, оказалось что ее сопротивление больше чем в игре. Пока в раздумьях. Будем уточнять геометрию модели, потом повторим. Но с большой вероятностью из Р-27ЭР выжать больше ничего не получится.

А на сколько больше сопротивление? На сколько это может отразится на дальностях, и потери в маневрах? Получается что мы в ближайшее время получим р27эр с CFD?

Да ,а по 77-й если будет лофт, то по примеру 120-й с какого расстояния он будет, и с какого расстояния он не будет? Просто не понятно как это можно вписать в 50 км для мига, на разных высотах, и для j11 для большего расстояния. 


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2 hours ago, Chizh said:

Р-77 пока не проверяли.

Р-27ЭР продули, оказалось что ее сопротивление больше чем в игре. Пока в раздумьях. Будем уточнять геометрию модели, потом повторим. Но с большой вероятностью из Р-27ЭР выжать больше ничего не получится.

 

Но как-то вы из AIM-120 +20-30% выжали, без лофта. Р-27Э и 120 были обы сделаны 7-8 лет назад. Как получилось, что это старое моделлирование было супер для Р-27Э, но американская ракета была на столько хуже чем сейчас?

 

Маленькая необъективность модели, скажим какой-то пессимизм со максимальный скорости, может сильно влиять на результат, тем выше высота пуска, чем хуже.

When ED reworks russian missiles:
 


(April 2021 update)

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1 hour ago, FoxAlfa said:

 

 

Could it be the difference between 3 sec burn at with a weaker sustain as in DCS instead of 2 sec burn with stronger sustain as in some tables that is causing the difference? 


The 2 sec burn would increase the range but reduce the speed, better long-range config in my opinion, R-27R should be for a closer range anyway. 

Current DCS config (if I am getting the math right) is 3sec at 7500kg and then 7sec at 1480kg vs 2sec at 7500kg and then 8sec at 2238kg. 
The energy sum is the same. 

sootvetstvuet_li_semejstvo_r27_1.jpg

 

 

Problem is that if you keep the fuel weight the same for each stage this would bring the ISP for the first stage unrealistically low (~156sec) and the ISP for the second stage way too high (~354sec). Which unless the current fuel distribution between boost and sustain is also wrong makes the second option impossible.  Which begs the question where did the current fuel/thrust characteristics come from?

 

Проблема в том, что если вы сохраняете вес топлива одинаковым для каждой ступени, это приведет к тому, что ISP для первой ступени будет нереально низким (~156 с), а ISP для второй ступени-слишком высоким (~354 с). Что, если только текущее распределение топлива между наддувом и поддержанием также не является неправильным, делает второй вариант невозможным. В связи с этим возникает вопрос, откуда взялись нынешние характеристики топлива/тяги?

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Пустите Р-27ЭР и AIM-120/AIM-7. Сравните скорости ракет до конца работы двигателей. По моему это более интересно чем сопротивление.

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When ED reworks russian missiles:
 


(April 2021 update)

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14 hours ago, nighthawk2174 said:

Problem is that if you keep the fuel weight the same for each stage this would bring the ISP for the first stage unrealistically low (~156sec) and the ISP for the second stage way too high (~354sec). Which unless the current fuel distribution between boost and sustain is also wrong makes the second option impossible.  Which begs the question where did the current fuel/thrust characteristics come from?

Yeah, true, ISP are off but the stage weights also seam arbitrary slaped on.

 

I did come across 2-8 sec split instead of 3-7 on other misslie forums and sources too.

 

Some of them were talking about new 2014 version with 9000kg stage instead of 7500kg... I didn't find the claim credible enough to share...

 

All in all 2-8 gives higher end speed at longer range but it takes longer to get there so I am not sure what is better.

 

If you were supposed to use R-27R at closer range I would go for that configuration, if the R-27ER was supposed to replace the R-27R I would go for 3-7... 

 

 


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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17 hours ago, FoxAlfa said:

 

 

Может ли разница между 3-секундным прожигом с более слабым сустейном, как в DCS, а не 2-секундным прожигом с более сильным сустейном, как в некоторых таблицах, является причиной разницы? 


Двухсекундный ожог увеличит дальность, но снизит скорость, лучшая дальнобойная конфигурация, на мой взгляд, R-27R в любом случае должен быть для более близкой дистанции. 

Текущая конфигурация DCS (если я правильно понимаю) составляет 3 секунды при 7500 кг, затем 7 секунд при 1480 кг против 2 секунд при 7500 кг и затем 8 секунд при 2238 кг. 
Сумма энергии такая же. 

соответствует_li_semejstvo_r27_1.jpg

 

 

You can try different configurations by changing the parameters in the missile script missiles_data.lua

 

17 hours ago, Hoarfrost said:

А на сколько больше сопротивление? На сколько это может отразится на дальностях, и потери в маневрах?

Скажем в районе 10%. В любом случае если мы применим коэффициенты рассчитанные через CFD ракета будет летать немного медленнее и ближе.

 

Quote

Получается что мы в ближайшее время получим р27эр с CFD?

Пока нет. Нужно будет еще уточнять и выверять геометрию чтобы повторить опыты.

 

Quote

Да ,а по 77-й если будет лофт, то по примеру 120-й с какого расстояния он будет, и с какого расстояния он не будет? Просто не понятно как это можно вписать в 50 км для мига, на разных высотах, и для j11 для большего расстояния. 

Не могу ничего сказать. Про это ничего не известно.

 

Я не смотрю телевизор

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16 hours ago, Max1mus said:

 

Но как-то вы из AIM-120 +20-30% выжали, без лофта. Р-27Э и 120 были обы сделаны 7-8 лет назад. Как получилось, что это старое моделлирование было супер для Р-27Э, но американская ракета была на столько хуже чем сейчас?

Потому что изначально все коэффициенты для AIM-120 были поставлены от балды. Именно из-за того что по ней было больше всего неопределенностей, мы и стали ее исследовать в первую очередь.

 

 

Я не смотрю телевизор

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18 hours ago, FoxAlfa said:

 

 

Could it be the difference between 3 sec burn at with a weaker sustain as in DCS instead of 2 sec burn with stronger sustain as in some tables that is causing the difference? 


The 2 sec burn would increase the range but reduce the speed, better long-range config in my opinion, R-27R should be for a closer range anyway. 

Current DCS config (if I am getting the math right) is 3sec at 7500kg and then 7sec at 1480kg vs 2sec at 7500kg and then 8sec at 2238kg. 
The energy sum is the same. 

sootvetstvuet_li_semejstvo_r27_1.jpg

 

 

 

I've tried to do some very rough basic calculations:  (320 m/s at launch at 1000m)

 

- Current situation with the 3/7 setup : missile reaches around 1040 m/s, 3 seconds after launch, then 7 seconds later it ends up flying at around 935 m/s when fuel runs out

 

- With the 2/8 setup based on this doc: the missile would be around 800 m/s at 2 seconds with the 1st stage, then it would continue to accelerate reaching 1050 m/s 8 sec later.

 

trying to calculate the distances:

 

-currently missile is out of fuel 9 km from launch at 935 m/s speed

 

- I think with 2/8 setup: it would be out of fuel at 8,7 km from launch, but traveling at 1050 m/s  -----> the missile would travel around 1,2 km while decelerating from 1050 to 935 m/s

 

So overall I guess the missile would burn out at 0,3 km less distance from launch, but gain +1,2 km glide, so overall it could be around 0,9 km + flyout distance. 

 

It seems DCS uses a constant average acceleration for the first 3 seconds, and I used that to guess the speeds for the 2/8 config, so maybe the 1st stage speed would be lower still with the 2/8 setup, only around 760 m/s instead of 800 m/s

 

In this case gain would be lower, maybe just a couple hundred meters flyout distance.


Edited by HWasp
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1 час назад, Chizh сказал:

Не могу ничего сказать. Про это ничего не известно.

 

Будет тоже проведена большая работа по р77? После р27эр? В этом году?

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1 hour ago, HWasp said:

 

I've tried to do some very rough basic calculations:  (320 m/s at launch at 1000m)

 

- Current situation with the 3/7 setup : missile reaches around 1040 m/s, 3 seconds after launch, then 7 seconds later it ends up flying at around 935 m/s when fuel runs out

 

- With the 2/8 setup based on this doc: the missile would be around 800 m/s at 2 seconds with the 1st stage, then it would continue to accelerate reaching 1050 m/s 8 sec later.

 

trying to calculate the distances:

 

-currently missile is out of fuel 9 km from launch at 935 m/s speed

 

- I think with 2/8 setup: it would be out of fuel at 8,7 km from launch, but traveling at 1050 m/s  -----> the missile would travel around 1,2 km while decelerating from 1050 to 935 m/s

 

So overall I guess the missile would burn out at 0,3 km less distance from launch, but gain +1,2 km glide, so overall it could be around 0,9 km + flyout distance. 

 

It seems DCS uses a constant average acceleration for the first 3 seconds, and I used that to guess the speeds for the 2/8 config, so maybe the 1st stage speed would be lower still with the 2/8 setup, only around 760 m/s instead of 800 m/s

 

In this case gain would be lower, maybe just a couple hundred meters flyout distance.

 

Hey, thank you for doing calculations! I also got roughly ~10% range gain, but effective range against maneuvering target should be bigger ~10% since the missile in a better drag speed range longer.  Alos it would give that 10-15% range gain we are all hovering around.


So, my proposal for the change is to change R-27ER to 2, 7500 - 8, 2238 configuration and keep the current drag.

That would make sure that missile passes the graph range at all altitudes with some energy to spare, also increase its effective range without influencing the straight line one substantial. 

 

the trade-off is lower max speed of the missile... but again, ER wasn't made out performer R close range, but to go the distance.  

 

Of course, independent bugs with EO and Chaff should be fixed as well. 


 


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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52 minutes ago, FoxAlfa said:

 

 

the trade-off is lower max speed of the missile... but again, ER wasn't made out performer R close range, but to go the distance.  
 

 


ER is quoted to outspeed most missiles in terms of max speed. I think ED needs to look at the rocket motor simulation of the missile again.

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When ED reworks russian missiles:
 


(April 2021 update)

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3 minutes ago, Max1mus said:


ER is quoted to outspeed most missiles in terms of max speed. I think ED needs to look at the rocket motor simulation of the missile again.

Faster you go, more drag hurts you...when you have limited energy supply you don't want to overspeed it but keep it in certain speed range to get optimal performance.

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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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