RVV-AE trials were ended in 1991, first delivery in 98
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R-77 would also have substantially higher base drag from its short burn time
As for it being accurate, it exceeds the stated max range by both the manufacturers parent company and the export company by over 25% and is only ~10% away from the stated max range of the RVV-SD which has a larger motor.
I have my doubts that it performs that much better than the most up to date manufacturer claims, and I have SERIOUS doubts that a hand drawing in a book about missiles prior to the introduction of said missile, regardless of it already existing, with the drawing not even providing altitude, but providing a loosey goosey range estimate of “something beyond 80km” would be an accurate source on range.
I also have major doubts about the grid fins as a whole as they are typically used for ballistic missiles, reusable rockets, or unpowered bombs carried in internal stowage like on the B-2, NOT in air to air missiles. And despite all the advantages they are claimed to have, they are used on the R-77 and R-77-1 missiles only for air to air role afaik, with even the R-77M abandoning the grid fins DESPITE their largest advantage being their packing, which is critical for internal storage like on the Su-57, which they are designed for, and no other nations afaik using them either. It makes me question why they are almost entirely unseen in air to air missiles, even hypersonic ones like the R-37M which would presumably make use of them much better than the R-77.
My theory on the grid fins, through some cursory reading, is that they were more of a holdover from the missiles development, as it seems it initially began development to be the missile of a future jet replacing the MiG-29/Su-27, which eventually became the Berkut and eventually, the Su-57. A key feature here being that both the Su-47/57’s had internal weapons bay which happens to be what grid fins are ideal for (packing). From a quick read, grid fins offer no real drag difference from planar fins at most flight speeds (subsonic or supersonic), offer better drag and control at high supersonic speeds (defined by NASA as 3 < M <5) and SIGNIFICANT drag penalties at transonic speed ( 0.8 < M < 1.3) with it being considerably worse within the 1.0 < M < 1.3 range.
With this information, I suspect grid fins are not typically seen on air to air missiles because air to air missiles don’t typically spend extended periods of time between M3.0 and M5.0. This would explain why something like the R-77M, which I’d bet money has fins designed to fit within the Su-57’s internal storage space, abandons grid fins as its REAL advantage over plannar fins (packing) can be designed around. I also suspect that the advantage of grid fins in drag at high supersonic speeds is likely also drastically reduced, if not eliminated, by the substantial increase in base drag caused by the short motor burn.
I’ll also point out that grid fins drag in the transonic region is SO BAD they are used as airbrakes in application like reusable space rockets.
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And significantly less drag above 2 mach thanks to grid fins, hence why I used the AIM-7F coefficient.
Karpenko made the graph in '93, no?
Yes. At least it’s the year the book was published.
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What is your take, should I change anything and re-test?
I don’t have anything to add currently
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Afaik the fins do not unfold prior to launch, they are manually unfolded on the ground. The switch to conventional fins was an attempt to reduce RCS of the missile itself more so than anything else.
Can you make similar for R-27EA
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Giving the R-27ER an active seeker and adjusting the weight would be a really simple task actually. Finding accurate information on the seeker ranges and whatnot would be the hard part.
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Really? So with the same drag as the AIM-7F and a lighter missile, it has less than 20km of range on the deck, as the graph shows?
I was primarily concerned with the maximum launch ranges of the graph, but you’re right. The bottom end seems to be far from accurate. There’s simply no feasible way the missile has such low range at that altitude. If you have better information for me to plug in and test please share so we can further our discussion.
I mean there is a very obvious answer- the missile has bad transonic drag and it spends much more time transonic in thick air at low altitude.
The missile acceleration would allow it to exceed mach ~2s post-launch even from 0 launch speed. The thrust to weight is far more than sufficient to overcome wave drag as well, so I think this is more of an error on the part of Karpenko.
It’s possible either the source is wrong, in which case, don’t use it, or your understanding of how the grid fins effect drag isn’t 100% accurate.
Karpenko doesn’t list any launch parameters and such for his source. He only indicated that the missile has a maximum range of 100km . When I was first passed the source it was inferred that it was a primary source. Now we know better, it is not well cited. Regardless, other better (and primary) sources gave me sufficient information to model and test the missile outside the parameters wherein wave drag would have some bearing on the performance of the missile. In these conditions, we can easily show the missile is capable of exceeding 80km range. In fact, if the missile was launched at higher speeds at a higher altitude target it would be more than capable of exceeding the 100km range estimated by Karpenko.
Drag can be a huge factor at low altitude, making missile acceleration much slower, and the transonic impact of grid fins extends well above Mach 1, starting around Mach 0.8, peaking at about Mach 1.15 and then falling off slowly. R-27ER from what I know doesn’t exceed Mach 3 from a low-altitude launch, and I doubt R-77 significantly exceeds Mach 2.
So the instant a source starts to indicate something you don’t like, you turn against it. Wow, such integrity. Shall I also point out that the brochure DracoMindC used to get estimates of impulse gives the launch range of R-77 as 60/20km(presumably head/tail aspect).
In general the biggest advantage of grid fins from my research is not drag at any speed, but rather the reduction in control moment forces allowing for less powerful servos. Which would align with the R-77 having a smaller aft control section.
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I’m not tossing sources I don’t agree with. If that’s what you think, please show me a better one. ROSOBORONEXPORT claims 80km range but the public data suggests the missile has more. Indeed, the in-game testing shows it is more than 80km.
It’s possible you are overestimating the battery life then.
Or underestimating the wave drag, or underestimating the base drag or a mix of all 3.
Incidentally, I was going to try to help estimate gaijins modelling of base drag by checking the Aspide 1 drag (3.5 sec burn) vs the AIM-7F drag (15.5 sec burn) but it seems gaijin has modelled them to be the same, which likely means the Aspide is heavily overperforming