MA_VMF Posted August 1 Posted August 1 Р-77 в сравнении с расчетом АиМ-120 от ЕД. Мощности компьютера не хватает так что сетка довольно грубая. И как объяснили на 1М-1.1М вышла какая то ошибка поэтому такой результат завышенный. Если разжиться мощностями и правильно с профилировать сетку можно добиться либо чуть ниже или чуть выше сопротивления null 2
tavarish palkovnik Posted August 2 Posted August 2 15 hours ago, MA_VMF said: Р-77 в сравнении с расчетом АиМ-120 от ЕД. Мощности компьютера не хватает так что сетка довольно грубая. И как объяснили на 1М-1.1М вышла какая то ошибка поэтому такой результат завышенный. Если разжиться мощностями и правильно с профилировать сетку можно добиться либо чуть ниже или чуть выше сопротивления null This looks nice and fair Lift coefficients will be needed as well, either Cy f(M) or Cn f(alpha), three Mach numbers will be enough (1, 2 and 3M)
tavarish palkovnik Posted August 2 Posted August 2 (edited) One very questionable method but result that I got is actually what I was expecting it will be Determination of hole's diameter based on two different reference measures and than finding third one which dropped out to be in level of what is in R-77 motor So it could be something like this, R-77 and R-77-1 nozzles, initial area ratios 14 and 10 respectively About propellant grain configuration, I think both motors have same 5-point star grain, here signs of slivers can be seen very nicely Edited August 2 by tavarish palkovnik
MA_VMF Posted August 2 Posted August 2 3 часа назад, tavarish palkovnik сказал: This looks nice and fair Lift coefficients will be needed as well, either Cy f(M) or Cn f(alpha), three Mach numbers will be enough (1, 2 and 3M) AoA=0, Lift=0
tavarish palkovnik Posted August 2 Posted August 2 35 minutes ago, MA_VMF said: AoA=0, Lift=0 Yes yes, I understand this was drag with AoA=0 but Cn function will be needed as well to make some external ballistics If you have time push the rocket at sea level 1, 2 and 3M and push it to 15 degrees to see Cn values. These 3 reference points should be enough
tavarish palkovnik Posted 17 hours ago Posted 17 hours ago Attempt to reconstruct this case, very low launcing velocity, fair altitude and very high distance to target. If it's true, number in circle present seconds till impact, so 100 seconds which is very long travel. I have no clue where is target on altitude and how fast it is so let's consider it to be same. Several options: 1) levelled flight 1G overload plus 3G reserve 2) initial lofting maneuver and ballistic trajectory but keeping 3G reserve Both of these cases are pointless, not even close to reach target 3) initial lofting maneuver, then ballistic trajectory without any overload and/or reserve and at the end gliding with 1G overload with included 3G reserve Only this thrid case can bring rocket that far and also to have at least some velocity at the end Approximately 67 seconds of passive flying object, with locked fins in zero position, with no lift force whatsoever. I have no clue could it be case, it is completly differnet approach compared to other Russian rockets, I mean on absence of this overload reserve. But only this way I manged to drag rocket that far 1
MA_VMF Posted 15 hours ago Posted 15 hours ago 1 час назад, tavarish palkovnik сказал: Attempt to reconstruct this case, very low launcing velocity, fair altitude and very high distance to target. If it's true, number in circle present seconds till impact, so 100 seconds which is very long travel. I have no clue where is target on altitude and how fast it is so let's consider it to be same. Several options: 1) levelled flight 1G overload plus 3G reserve 2) initial lofting maneuver and ballistic trajectory but keeping 3G reserve Both of these cases are pointless, not even close to reach target 3) initial lofting maneuver, then ballistic trajectory without any overload and/or reserve and at the end gliding with 1G overload with included 3G reserve Only this thrid case can bring rocket that far and also to have at least some velocity at the end Approximately 67 seconds of passive flying object, with locked fins in zero position, with no lift force whatsoever. I have no clue could it be case, it is completly differnet approach compared to other Russian rockets, I mean on absence of this overload reserve. But only this way I manged to drag rocket that far https://youtu.be/RvmHMgEPCQM?si=62fddx3-sA_Upx91
MA_VMF Posted 15 hours ago Posted 15 hours ago https://youtu.be/KpXol98UDeA?si=I9VAA9cZpqo2n82O Тут скорость 1.3М дальность 40 км , цель летит со скорость 945 км/ч Высота не известна Я думаю около 8-9км
tavarish palkovnik Posted 12 hours ago Posted 12 hours ago I think I will need to remodel a little bit my programs for trajectories. In all previous cases (mostly focus was on R-27R and R-27ER) I’ve never managed to fully match all envelopes of launching, usually at 10km I was very close to match it, but on higher altitudes I always had a little bit underperformed results. Reason is most likely in incorrect involvement of this overload reserve (запас перегрузки или дополнительное нагружение). I was simply just making sum of kinematic overload, for example 1G for leveled flight, and 3G as reserved overload, making total of 4G, and used same for all altitudes. But most likely it doesn’t work that way, it is not just sum and most likely запас is not same for all altitudes. This is not related to air-to-air rocket but principles could be same or similar. In this case for targeting at altitude 10km calculating overload is 3,1 (total ones) but for 15km 2,7 , 2,2 at 20km etc etc, and that same principle could solve my mismatching.
F-2 Posted 11 hours ago Posted 11 hours ago Magic II https://web.archive.org/web/20060520212955/http://www.bayernchemie-protac.com/magic_2.htm MICA https://web.archive.org/web/20060520212926/http://www.bayernchemie-protac.com/mica.htm
tavarish palkovnik Posted 10 hours ago Posted 10 hours ago (edited) 47 minutes ago, MA_VMF said: nullnull Yes, that’s it, always some polynomials which define trajectories to have maximal velocity when rocket reaching target and to be kinematically released when starting to chase target Edited 10 hours ago by tavarish palkovnik
nighthawk2174 Posted 4 hours ago Posted 4 hours ago On 8/2/2025 at 8:30 AM, tavarish palkovnik said: One very questionable method but result that I got is actually what I was expecting it will be Determination of hole's diameter based on two different reference measures and than finding third one which dropped out to be in level of what is in R-77 motor So it could be something like this, R-77 and R-77-1 nozzles, initial area ratios 14 and 10 respectively About propellant grain configuration, I think both motors have same 5-point star grain, here signs of slivers can be seen very nicely With such methods its best to do a lower and upper estimate which will give you a reasonable range of results. It can be difficult to get exact measurements from photos but depending on how accurate you want to be they can suffice for a reasonable estimate.
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