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The velocity on HUD you call "target velocity" is not target velocity IRL. It's called "скорость заданная истинная" as you may see on BlackPixel's screenshot. In english it would be somtehing like commanded TAS or requested TAS.

Hello, I'm not in charge of development plans. Regarding R-27ER range... we already say that unfortunatley chart quality is not very good. There is no any chace to perfectly match this charts with any realistic drag and thrust values. Say, if we adjust missile to match chart at 5km rear hemisphere it wont match all other points! Current drag values for 27ER/ET is good compromise to be close to all chart points at a time. Here another one chart with new/old 27ER performance comparison. As you may see missile achive official numbers at least at 10km altitude

We know this trick, but as you have noticed it's not correct. Moreover it's not precise enough. Wing interference leads to noticeably lowered drag. Ref. area for charts form report is 0.9 sqm.

Это один из лучей звездочки в разрезе, т.е. там пустота.

Our current estimation matches Fleeman's book. But Fleeman in fact does not match SMC. Look, SMC tells us Boost 5750lb for 4.5s -> total boost impulse 25875lbs. 83lb of propellant -> 312s Isp Sustain 1018lb for 11s -> total sustain impulse 11198lbs. 52lb of propellant -> 215s Isp Total propellant weight 135lb, total motor impulse 37073lbs -> average Isp ~275s Does not look very realistic for me. Ok, let's see what Fleeman tells us(page in attachment)... that looks ok. Note, motor data in attachment is for 20Kft altitude, at different altitude thrust(and Isp) will be different too. The reason for this is pressure losses in nozzle due to atmospheric pressure. So at SL Isp is minimal and increases as altitude increases. This modeled in DCS, and motor data you see in scripts is for SL. DCS AIM-7 motor data matches Fleeman's one(with recalculated Isp for SL 247 and 209s). Ok, will take a look Yep, approximately. Range may be a bit wider depending on conditions(propellant temperature, chamber pressure, exit pressure etc ), but upper bound should not exceed 255-260s for real motors in normal conditions.

Excellent. Now you may see what there is definitely some issue with launch range charts. We have this document too, but at the moment the best reference for us is Fleeman's book, please pay your attention to motor data in this book. Regarding time of work and thrust...first of all you should consider what the main thing you need to know is the total impulse of motor. Even if you change burn time(within resonable limits) and thrust, but retain total impulse the same you will not get noticeable difference in missile performance.When you change only time or only thrust Isp of fuel(and total motor impulse) became very wrong. We know exact amount of propellant from several sources and it is 133lb. We know the type of fuel and Isp so our estimations is correct. It wont lead to very different performance, because we know mass of fuel and Isp, even when you don't know the exact Isp there is still hard limits on its value and thus limits on error in performance. But as I said above the Isp is known at least form Fleeman's book.

Yep. My mistake, should be 4nm, but typo is still here. Ok, let's suppose chart is correct, in this case new question arises - how this possible? We know that drag is correct(several sources match), motor data is correct too(from Fleeman's book for example), hence missile range should be correct too. It cannot be lower two times.

The first reason is charts inaccuracy. See attached. SMC chart has a typo on its scale. With account for typo range is 2nm = 3.7km (and that's exactly we have in DCS for Vt+150m/s terminal condition). Russian chart is not ideal to. For tail-chase case curves for Vmax and Vmin match at low altitude, but there should be no such thing. The second reason - you cannot just take two different charts and start to compare them(SMC chart gives you 20nm for head-on case at SL, but russian one only 20km, hmm, why?). Charts may be drawn for different velocity conditions(Vt/Vf ratio may not equals 1) and different terminal conditions. So you may directly compare two charts only if all this conditions match.

Hi, you may find many interesting info about AIM-7(referred as missile baseline) in Eugene Fleeman's book Tactical missile design, chapter 7. Here for example original CD0 chart from this book. Triangles denote data from NASA wind tunnel test, x'es with lines is for our CFD data.

Lift coeffs were changed in august 2020 update.

Это уже давно, с самого начала было в их обновленных фм.

I hope so. At least ballistics of AIM-7 matches the real one, ballistics of AIM-120 should be close to real one.

As much as it should For AIM-7 this reduction known from docs/real wind tunnel tests, for AIM-120 from our CFD research.

Aim-7 and aim-120 use new FM which models drag reduction due to thrust.

Yes, think we will not change ballistics anymore, at least until development of new FM. new FM may give another 4-5% of range at low altitude. 150m/s is not only for proximity fuse it's a kind of margin for some other reasons as well, common prictace for all AA na SA misiles Yes, the chart I posted above takes into account that additional 150m/s More realistic boost-sustain impulse distribution, but total impulse the same. Снижение скорости улетающей от нас цели дает больший прирост дальности чем ее прирост от увеличение скорости носителя(и соответственно средней скорости ракеты)

We know this is a safety margin. It is necessary mainly because of different ambient tepmerature and some total impulse variations(from motor to motor). All data we have we take seriously. But unfortunately, different sources often does not match and have some differences and we should careful think how to merge data and what source is the best. Also whe check data by calculations when it possible. BTW, the body base drag is not such powerful as you may think. You really think what such a simple mistake as wrong air density may be unnoticed for years? Ballistics of every weapon we add to DCS or update we carefully calculted with using ISA befor adding into DCS. If thre was any mistke with atmopshre in DCS it would be noticed as mismatch between DCS and calculations. Anyway we have chaged R-27ER/ET thrust profile and zero-lift drag beacse there was made some mistkes (those missiles were adjusted togeter with communtiy many years ago) such as worng terminal condition for rear hemispere launches (missile velocity should be equal to target one plus 150m/s, but not just equal). Below you can see impact of this changes on missile range. Pay your attention to chart grid and original semi-circles mismatch and quite too big distance between dashed and solid curves at 5km altitude, rear hemisphere. All this is obvious mistakes of typography, original drawing or somewhat else. New adjustment of missiles is the best in terms of minimum of total mismatches at all velocities and altitudes. RU Мы изменили профиль тяги и сопротивление при нулевой подъемной силе для Р-27ЭР/ЭТ потому что при настройке были сделаны некоторые ошибки(кто забыл, напоминаю: большинство ракет было настроено совместно с комьюнити много лет назад и эти ракеты - не исключение), вероятно при настройке использовались неверные условия встречи для пусков в заднюю полусферу(при попадании скорость ракеты должна быть равна скорости цели + дополнительные 150м/с). Ниже вы можете видеть как повлияли новые настройки на дальность полета ракеты. Обратите внимание на несовпадение сетки графика и оригинальных полуокружностей, а так же на слишком больше расстояние между пунктирной и сплошной кривой на высоте 5км в задней полусфере. Все это очевидные типографические ошибки и ошибки исходного расчета/построения. Новые настройки являются лучшими по минимум несовпадения с оригинальным графиком на всех скоростях и высотах.

Масса топлива известна, тип топлива и размеры сопла тоже. Удельный импульс топлива выбран исходя из усреднённого значения по паре двигателей с таким же типом топлива и справочнику по топливам. Время работы - по видео пусков. Удельный импульс двигателя - газодинамический расчет с учетом потерь. Это достаточно точная оценка.

Типографическую ошибку. На этом гарфике даже расстояния между радиусами неодинаковые. Разницу межу 50-60км и 40-50 км видно невооруженным глазом.

Thanks! Very interesting!

Hi, what is the source of chart? Is there any reference area value for it?

Can you please provide a tack with F-15C instead of M2000?

Transmitter on the second place by power consumption. The first place for fin actuators. Also INS has a finite accuracy(time-dependent), so there is no point to increase battery capacity.

We remember about this issue. Unfortunately, there is no quick and easy solution(it requires rework of fundamentals of radar mechanics and chaff, which may cause other problems). So, please be patient, complete solution will take a long time.

С чего ты все это взял? Стабилизация включается через 0.5 сек после поджига двигателя, еще через 0.5 сек наведение, т.е. секунда разгона. Далее, опять что за максимальная эффектиновсть? Эффективность такая, какая должна быть на этой скорости. Нет никакой проблемы выкинуть малоустойчивую ракету с небольшим моментом инерции на угол атаки 25 градусов за 0.25 сек(можно даже быстрее, но это уже будет менее реалистично с точки зрения полосы пропускания контура управления). Не надо выдумывать, нет никакого фанатизма в отношении американской школы. В предыдущей итерации ракет их маневренные возможности были заметно ниже реалистичных. Постепенно мы это исправляем, недавно(пару патчей назад) была обновлена аэродинамика ракет Р-27 и Р-77 в рамках старой модели и та же Р-77 сейчас рулит на старте не хуже амраама.

В каком смысле максимальных и почему 0.3сек? Это какая-то неправильная постановка вопроса. Ракета имеет относительно низкую устойчивость и большой ход рулей, при максимальном отклонении угол атаки на канал на дозвуке получается где-то 22-25 градусов, переходный процесс на скорости около 900 км\ч займет около 0.25 сек с текущим автопилотом и рулевыми приводами. На таком угле атаки работающий двигатель дает еще 4-5 единиц перегрузки.