I think the Russians also understand if you want long ranges necessary for a BVRAAM you need to not use grid fins. The R-77M/K-77ME are all seen to have a solid tail assembly like an AMRAAM
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Unfortunately no where in that paper that was said. AoA vs drag is something completely different since same with Delta wings, that would be different when flying straight. Also the conclusion is in fact that it is superior at higher speeds.
Quote:
The research concluded that the grid fins
performed better at high Mach numbers and
high angles of attack.
R-77M uses solid tail assembly to reduce space for internal weapons bay of Su-57. Folding mechanism for grid fins was found to be not as reliable as you would want, at least from info that i could find. And KS-172 aka AAM-L still has grid fins on a booster stage despite being a long range weapon design.
Actually, grid fins have greater control effectiveness than planar fins.
less than it is now but yes more drag. It does make it more manoeuvrable but btw that isn’t the concern of mid range missiles.
R-77 was designed as close-mid range weapon, because USSR generally had a big emphasis on close range combat in it’s air doctrine.
R-37M doesn’t use grid fins, R-74M doesn’t use grid fins this was an oddity to try and get close range and medium range performance.
Yes modifying missile to fit weapon bays is common. The R-77ME with the ramjet also has fixed fins.
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did you miss this? “Grid fin produced higher drag than the planar fin for all cases.”
at the end of the results and discussion section
and one of the charts showing a significantly higher coefficient of drag, that out to ~12-13 degrees AOA is over twice the drag of a planar fin. If the drag over AOA chart did not extend to 0 degrees of AOA it would be less relevant but the chart shows the grid fin as having over 4 times the drag at 0 degrees of AOA which is a massive performance detriment.
and on top of that, the data in that chart was taken at mach 2.5 where the grid fin is preforming best, the disparity in drag will significantly increase as mach number decreases.
also looked back over it and it is showing that planer fins had a better lift to drag ratio than the grid fins out to ~20 degrees of AOA, meaning that they would have less parasite drag and induced drag for the same moment applied to the missile, which is the conditions the missile operates in for most of its flight time
All cases of AoA. Nothing to do with speed. Also Lift coefficient is subject to surface area. E.g. this would be what it looks like for delta wing
yet in no AoA situation this is completely different.
wtf are you saying
this is at a set speed of mach 2.5 showing drag at all conditions (AOA 0 degrees and above) is higher for grid fins than planar fins
it is not completely different in a no AOA situation, as you can see the graph extends to include the no AOA situation where even at mach 2.5 grid fins have 4 times the drag of planar fins and that discrepancy increases as mach number decreases
R-37M doesn’t use grid fins because it is a development from R-33, and R-33 was developed to be carried under MiG-31 fuselage on semi-recessed pylons. R-74M doesn’t use grid fins, same as R-73 because it’s designed with completely different layout scheme. If you are trying to prove a point please use arguments with a proof, not pure speculations.
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Bro you can just Integrate the grid cross section and compare with others, it is still higher, besides grid mean more surface area and creat more skin fractions, especially when you are turning.
The design meant to trade drag into turning capability, and now you said the drag is too high？
Huh？
Drag behaves differently at supersonic speeds.
And show that graphic with any amount of AOA, guess what happens?
It’s called a trade-off for a reason, and one that the rest of the world realized was not worth it
even at no AOA it is a lot higher, the paper I linked earlier stated over 4 times at 0 degrees AOA
It’s higher than the plane fins but in the game, the drag is much higher than irl, R77 can’t even reach 10 km lol
Right… We just straight up lying now I see
Does anyone have drag coeffecient to aoa comparison graph here for planar and grid?
wdym R77 can’t hit a maneuvering target at 10 km