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tavarish palkovnik

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Everything posted by tavarish palkovnik

  1. R-27 and 27E have turbogenerator which is source of electric power, just to be mentioned
  2. That’s better, and honestly I’m looking forward to read about further actions as I also have some kind of strange interest for these curves and trajectories are in indeed with lot of curves, continuously and frequently changed
  3. This is very ambitious statement. Although not user, I hardly doubt you managed to program mathematical method of inertial navigation of these rockets, method that can be easily described in mathematical form but hardly “molded” in universal form. Please don’t take me wrong, but sometimes it’s better to say, we did our best
  4. Again again please… “R-27ER outperforms the AIM-7M mostly in everything but weight” Please try to explain this oxymoron to me, or my english is really bad. It means R-27ER is “better” but it is not good because it is heavier?
  5. Oh my god, based on what this conclusion is made?
  6. Р-27Р/Т пнв 1983 г. Р-27ЭР/ЭТ пнв 1985 г. Just to be mentioned when exactly these rockets entered in service www.oboron-prom.ru
  7. May I ask for a source of SD-10 (PL-12) motor specifications used in DCS, 57,6kg and 11,6kg, 6 and 4 seconds, 242/236s By the way, РДТТ Р-300Э, I never found any reliable document that motor had or has this designation
  8. Forgot to say...this method is appliacable only for velocities >0,8M !
  9. Only for 5V21 but that should fits to 5V28 with no doubts I guess you are Russian speaking so you will not have problems with these graphs. Only I need to check what is reference area and I will share it as soon as got it. Something with wings because in that time wings were usually base
  10. Now when have some Cx f(M) why not to make some shot to see how far it could fly. There is one nice iteration method, rough but nice, not very suitable for long active time and altitudes over 10km but I will turn a blind eye this time So 12km, horizontal flight, same velocity of fighter and target (325m/s), I want of rocket to have velocity of 600m/s when come to target, density of air is 0,3118, average chamber pressure let's say 70 bars, let's say gases will expand fully to ambient pressure of 0,02Mpa, average calculating impulse 240s, average drag coefficient 0,65 and iteration is that rocket will fly all together 37480 m and that distance will reach in 45 seconds. It means 52km is fireing distance And now method with integration... Or Mach number if more suitable And finally distance Iteration is very close to integration, or opposite, 38900m
  11. Based on my calculations for this missile and if nozzle exit is 125mm, average difference between active and passive is 8,5% Here is two samples, one rocket with widely opened nozzle (5V55 of S-300) and one with significant difference between body cross section and nozzle exit cross section (5V27 of S-125 ; 170mm vs 381mm) While in first case body cross section is refferent area, in second it is wings (0,96m2) so roughly pick in passive would be 0,67 if cross section (dia 381mm) is refference
  12. Shortly to explain these graphs, because I don’t believe that slight differences in form of rocket’s rear and generally slight differences in drag coefficients can change velocity in active time (motor ON) much. This program of mine is for ballistic flight, it’s true, but that shouldn’t change things much. I will explain later. Program is for single thrust models so I had to improvise a bit, four slides is one shot, two inputs and two outputs respectively. So first slide is start, 12km, 1,1M and ballistic shot with 10deg. Fourth is end and only velocity is what is subject to watch. So final velocity is 1207m/s or 4,09M. Program is based on law of Cx58, I don’t know how much you are familiar with it. Coefficients i58 active and passive are what should be relative to Cx58. So if I assume i58 as 1,3 and 1,45 and if and it is Cx58 at for example 1,1M 0,628 that means Cx (or Cd who likes more) is 0,8164 in active and 0,9106 in passive respectively (at 1,1M) Next 4 slides are simulation what if drag in active would be exactly same as in passive, no assist of flame whatsoever, base pressure drag is maximal whatever is exit diameter of nozzle. And such final velocity is 1195m/s or 4,05M. Difference of just 0,04M, just 1% ! Last 4 slides is next simulation, what if drag force would be somehow doubled, i58 2,6 instead of 1,3. Final velocity is 1103m/s or 3,74M or difference of 0,35M or decrease of 8,6% However, i58 2,6 means that rocket fly continuously overloaded with angle of attack roughly 10deg. Example, Cx58 at 4M is 0,302 and let’s assume Cy (lift coefficient) at 4M is 0,25. Cx=1,3*0,302=0,393 (zero AoA) Cx ind=10^2/57,3*0,25=0,436 Cx total=0,829 or roughly double more then unloaded Cx. Forgot to say, reference area is always cross section of rocket. So, all together, Cx in active does not influence a lot, it is insignificant in the matter of fact. Weight of fuel and impulse of fuel primarily and thrust force distribution in time secondary are the ones that change things significantly !
  13. Comparing to photograph, motor indeed could be around 2080mm what makes this very interesting. This is situation with Mk-58 of AIM-7F, two grains burning at the beginning together and then only sustaining one. The one is 23,6kg, other 37,7kg having different burning rates. Roughly speaking in first 4,5 seconds 45 kilos of fuel burn and rest remaining 11 seconds. Not for my taste but it is as it is. If similar principle will be applied to motor of PL-12… It is about 69 kilograms of fuel in total, exactly what DCS use if I’m not wrong. But if this configuration should burn for 6 seconds using 57,6kg of fuel and remaining 11,6kg for next 4 seconds then it should looks something like this… And it looks horrible, unreal. I don’t know source of this distribution ratio, I don’t know if this perhaps is result of “squaring” thrust curves or something else but simply it doesn’t looks natural. And what influence more, exit diameter of nozzle or perhaps thrust distribution in time. Usually area of exit is around 10 times bigger then cross section area of throat so it can gives some clues about pressure in chamber and respectively burning rates
  14. Good day to all ! Here is one rear view at operating PL-12 missile if it will be helpful Is there anyone who could translate this, is it written anything about missile this motor is related for? Motors and burning processes are interest of mine and I saw that in DCS this PL-12 or SD-10 has very awkward buster-sustain distribution and ratio. If info I got is not wrong, in buster stage of 6s 57,6kg of fuel is burned, and in sustained stage 11,6kg for 4 seconds. Interesting indeed. What exactly is length and weight of this rocket, internet gives values in contradiction, 3934mm 3850mm, 199kg, 180kg etc etc Actually what I’m looking for is origin of this motor I believe it must be somehow related with R-77 in some stages of development and using its motor for other applications (surface to air variant) and these Chinese missiles which have roots from R-77
  15. Great, thanks a lot
  16. Is anything new appeared in the meantime? Is there any new document published somewhere? About motor, ballistic, anything
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