tavarish palkovnik

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

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

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)

Anyone has idea (some tools) how to figure out what could be hole's diameter. Picture frame (focus) was not taken very happily and I think diameter is not so small as it looks on first view. R-77-1 of course is on picture. Actually I don't even know nozzle exit diameter so that info would be also appreciated

That is good point and question in same time. Do we have actually valid document that give 190kg to 77-1 ? For R-77 sources say 175-177kg and extra 110mm (R-77-1) supposedly made total of 190kg. Now new extra of 300mm made R-77M but this extra 300mm I count only as extra length of motor and that is just propellant and chamber casing what is 15-16kg

Few more words about new motor...of course dual impulse concept is just thought what could be inside. However sometimes the most simpliest is the most realistic and just simple single thrust motor should not be excluded, motor in form of regular R-77 motor, only on steroids Why I didn't exclude this...calculated first impulse that I got simply is not powerfull enough to push rocket in lofting. Not enough kilograms of force to lift rocket without significant loss of velocity. It's nice to have second impulse but pointless if first one didn't make good start. This is however someting else, this is very powerfull and potent motor. Still not very good solution for levelled flight (same 10km altitude and 500m/s starting velocity) -> but...this motor can easily lift starting 200kg in very nice lofting without lossing too much in velocity Dual thrust concept beside these two remains, but I really don't see such a long 200mm caliber motor in dual thrust concept and I'm not going to consider it

Don't advocate for others...others will do it themselves if feel as needed. Out and over

In any case we will know more and better when first motor case appears, when we see on it specific marks which will give answers. This is actually nothing new, more then 20 years is how much this motor is in connection with multy impulse concept

I thought it will be perfectly clear, anyway, red curve is case if second impulse would be started immediately after first one is finished. Green curve is case if second impulse would be started in 25th second and of course blue curve is with started second impulse in 45th second. One more realistic situation, levelled flight at 10km and starting velocity 500m/s First and second impulses one after another, something like dual thrust motor...and case if second impulse would be started when velocity drop to approximately 1M Combined cases -> Obviously dual impulse is with intention to make rocket with more potential in time when it counts the most, in time when target suppose to be hunted. Fact is that such concept, I think in most cases, gives shorter range and rocket is less agile considering total flight time, but when it matters then such rocket is with potential

I've never made fun with @MA_VMF !!! Actually I apprciate his work a lot

For drag coefficient function I’m quite confident it shouldn’t be something drastically different than presented. Not first configuration I calculated in old fashioned way This other issue is open…60 seconds or 120 seconds and are they changed principles (I hope they didn’t) to match cowboys in exaggerating with air-balls hitting one in hundreds case For now, at least to me, this is reality

Пуск…ракета пошла ! 15km altitude scenario, leveled flight, 3G reserve included, some theoretical top high starting velocity, starting weight 200kg. And ignition of second impulse right after first finish, in 25th second and in 45th second. Pictures show everything so no need to waste words. This exact, I think, rocket is described in one of the patents. There they mentioned that realistic thrust of second impulse could be 1000kg and weight of rocket, after both impulses are out, in level of 120kg. Based on the text, idea is to start second impulse in way that it finishes couple seconds before rocket reaches programmed point of impact in target. And…NO, this rocket doesn’t reach distances 100, 150, 200km as internet already started to drop nonsenses

Ready for pusk

First iteration about this new one

Already in active usage

New model from R-77 family starts to fly. Looks something like 300-350mm longer rocket and if I would give dual impulse to any rocket, this one would be that

When mentioned Sparrow, I don’t know if already had conversations about this drag function attributed to Sparrow Don’t like this “all altitudes” but never mind, differences are not so dramatic. But this function without reference area is not much useful… In any case, it should be area of two fins making peak as 0,84 counting with body cross section area

I was questioning why and how comes there is no yet on internet drag function for R-77. Really it is not easy to calculate such configuration, actually I'm giving up of it. Simply I don't have enough literature to make some reasonable, at least approximative calculation. All other rockets with normal fins can be quite easily calculated and results were not so bad, actually where had valid data to compare, not bad at all. There are several paper works but mostly they have focus on drag of individual fin, and I'm interested in full assembly. I was mentioning base pressure, one of the easiest parts of total drag calculation, but here with grid fins I just stuck and don't know how to proceed. And like said already, I'm expecting this part together with pressure on fins to be significantly higher then what is case with classic fins or wings whatever is in aft zone Few such aft section surfaces, Phoenix, Sidewinder and Sparrow For all these configurations base pressure can be easily calculated, and this ''c'' number (ratio between wing thickness and aerodynamic chord) is for these samples approximately 0,036 ; 0,046 and 0,09. What grid fins make on body base I have no idea ...

@MA_VMF Don't take me wrong but it would be fair to write few words with applied image, otherwise images become ->

New tricks, single image for two different situations ? Bottom is sea level seems like, and top side something higher altitude, and looks like some higher velocity then 0,8 mach number. And I'm very curious to see how this ''blue'' part (vacuuming) will develope with velocities

It’s kind of hard to find some texts with given numbers of drag coefficients for full assembly, for rocket with grid fins instead of for fins only. This is from one of such rare paperworks. Configuration is some sticklike wingless rocket with not very aerodynamic nose and they made and gave numbers for three different diameters, 500, 700 and 900mm. Table shows numbers for 500mm configuration where Cx_rocket are drag coefficients for rocket without fins and Cx_full coefficients for rocket with included grid fins. Interestingly, and not surprisingly to me actually, added fins increase drag coefficients making them as much as twice higher in average. In finless configuration only pressure on nose, pressure on base and body friction participate. With adding fins, two more components appear, pressure on fins and fins friction. While second should not be something significant, first could be. But I think the biggest difference could be base pressure. The lowest base pressure will be of course always in finless configuration. Classic fins increase base pressure of course and I think grid fins increase it significantly

Not sure which kind of results for comparison will be the most suitable so few more, situation 1,5M and 10km

For comparison when numbers from CFD arrive...Cx58 added just for pictorial representation of differences

Mach number 0,8 will not help us a lot to figure out what could be final score. Of course it would be great if you can make as much situations as possible but I think the most interesting range, and range where I expect really significant drag, is between 1,1 and 1,8M. I hope you will manage to finish this interesting piece of work, and I'm expecting curve of drag coefficients in form a little bit different then it usually looks like

Sea level ; M=1,5 ; AoA=0 perhaps ? Bold prediction if it is sea level and 1,5M and of course if you extracted numbers -> Cx something about 1,25-1,3 Cn 3,7 (AoA=10deg) Cn 11 (AoA=30deg) ... or it is M=1,1 more likely ... 1,75 ; 4,4 ; 14,8 respectively