It is simply a double standard as Gaijin has accepted dozens on dozens of reports using datamined information.
That’s not why, and they do take bug reports with datamined values on a selective basis.
The CxK and length of the ordnance are two values we know are modified by the engine. You can give the R-77 file the same CxK and length as an AMRAAM and then modify only the mass, burn time, and thrust to match the AIM-120. It will perform exactly like the AIM-120 provided the loft profile is also the same.
This proves that the R-77 does not have any special code or changes made to account for lattice fins. It is modeled as a planar fin missile and has the drawbacks such as excessive energy loss from attempting high angles of attack. It has limited off-boresight capability for the same reason. It is hampered considerably by the lack of comprehensive dynamic drag coefficient and modeling.
I disagree, most missiles in-game are modeled for a medium altitude scenario and due to the lack of dynamic drag and thrust characteristics they underperform at high altitude and often times overperform at sea level. Look at the AIM-54 which has nearly 30% additional range over what it should in sea level conditions.
This particular missile is troubled with a myriad of other issues, such as a tendency to simply explode after around ~50km of travel. This is not a good example for you to use.
Yes they are “suffering”, as in, overperforming at low altitude where most of them are used anyway. R-27ER is missing ~25% of it’s maximum range in high alt and high speed scenario but they will not fix this or it will heavily overperform at low altitudes more than it already does.
So, I know there are the R-77 from 1994, and the R-77-1 from the 2000s, but what actually changes from it? Are there any physical changes to the body of the missile?
I know that the range improves from 80km to 110km probably thanks to seeker and newer tech, but are there any changes to the fins or anything like that?
This is more a short form response, where I just address the things you said, because in my eyes; you argue in bad faith within your response. Which is a big red flag in my eyes.
Okay if that is so, actually explain your point of view. Then link that discussion, along with sources that have been utilized in that discussion.
I don’t see how this is relevant. Again, you are hyper-fixating on a specific point – ignoring the larger consensus of my point. Do I know the exact surface area of the AIM-120’s fin at the moment? No. What do I know? That the grid in general covers a larger surface area and thanks to it’s geometry captures much more airflow. A traditional planar fin has the advantage of having an optimized airfoil, the lattice fin does not have this advantage.
You also assume that I am not aware of supersonic flow works in regards to lattice surfaces. While in-fact, if you recall, in my OP that you responded to – I said in the table that I formed that the drag becomes less prominent at higher supersonic speeds; as air flow increases.
I would go as far to say that this point is akin to a strawman, as you do not actually seek to engage with what I said; rather seeking to misconstrue it. Honestly quite dumb.
Again, you hyper fixate on a small part of my argument and in-fact slightly misconstrue it. I wrote that the high AoA capability is also a feature in the part above. But I will admit, I said long range munitions – but to clarify, I meant in the context of War Thunder. Where a AIM-120 is considered a long range munition. Once again, you don’t necessarily seek to engage with my points; rather to discredit them at every point.
Okay. Then what is correct? I asked you provide dimensions of the R-77 in my post, you did not. Can you do so now? And I said before, these posts do not represent the R-77 in particular; but they are similar. You still ignore the core findings of that report, because it doesn’t match the R-77 to a teeth. Why? It still serves as a useful insight into the performance of lattice control surfaces when compared to planar ones.
I’ll repeat myself, share the dimensional data of the R-77 along with the sources you use.
And now, these replies you left.
Yes? But you’re dismissing the core point of my post without actually addressing it. It is true that they can be used as airbreaks, but as I outlined in that post – higher drag when compared to planar fins is something that happens with lattice fins. You are driving attention away from what I am claiming, without actually refuting what I am saying with any tangible evidence.
All sources that I have read through on the subject confirm this as the case. In fact, here is a list of the sources I have read so far on the subject. 9 documents, in the past weeks. Can you please post the list of sources you have utilized in your research on the subject? So I can go through them, and the references in them.
And please don’t make such a red herring. It’s embarrassing.
My Reading List
Not in any particular order.
AN EXPERIMENTAL INVESTIGATION OF GRID FIN DRAG REDUCTION TECHNIQUES by Mark S. Miller and Wm. David Washington (1993)
LATTICE CONTROLS: A COMPARISON WITH CONVENTIONAL, PLANAR FINS by G. M. Simpson & A. J. Sadler (1998)
Viscous CFD Calculations of Grid Fin Missile Aerodynamics in the Supersonic Flow Regime by James DeSpirito and Jubaraj Sahu (2006)
Aerodynamic Analysis of Lattice Grid Fins in Transonic Flow by Karl S. Orthner (2004)
A Prediction Method for Aerodynamic Characterization of Grid-Fin Configurations at Supersonic Speeds by Theerthamalai Pakkiri, Mani S Santhanakrishnan and M Nagarathinam (2005)
Novel High-Performance Grid Fins for Missile Control at High Speeds: Preliminary Numerical and Experimental Investigations by Erich Schülein and Daniel Guyot (2006)
Forces and Moments Generated by Swept-Forward Grid Fins and Planar Fins by Marco Debiasi (2020)
Grid Fin Stabilization of the Orion Launch Abort Vehicle (2011) by Daniel A. Pruzan, Michael R. Mendenhall, William C. Rose and David M. Schuster
Analysis of Grid Fins for Launch Abort Vehicle Using a Cartesian Euler Solver (2011) by James E. Kless and Michael J. Aftosmis
Again – you do everything but actually engage with my point, practically handwaving it away without backing up your own words. So, please do; with sources like I have.
Again, you failed to look at the measurements yourself, and misunderstood the contents of the studies. And I said as much in the thread, that the I have been reading into the concept in general rather than exclusively focusing on the R-77 at the moment.
As I posted above, 9 studies varying from ones made in 1990s to ones made in 2020 that all have countless references come to the exact same conclusion that lattice fins exhibit more drag.
But; I will entertain you – as dismissive and lazy your point is, and I will read into it more. So, please, provide some of the sources you have read yourself.
You could have checked that yourself, but I admit I forgot to link them in the main post, as they had to be converted. Here are the conversions.
AFIT Paper Measurements
Table that contained the value for d (diameter)
Figure 14 of the paper converted into millimeters (from left to right: baseline fin, thin fin & “coarse” fin)
It’s evident that measurements were provided, for the thickness. For the baseline the thickness is 0.177 mm, for the thin one it’s 0.101 mm and the coarse one is the same 0.177m. But you are correct, the document does not mention taper ratio – but it does mention measurements.
I am also confused why you are mentioning taper, because it isn’t applicable to lattice surfaces because of lift generates differently for them. Taper ratio focuses more on the single plane aspect, thus it should be avoided.
Taper ratio formula
What we should measure instead is the Thickness-to-Width Ratio (t/w) or Width-to-Chord Ratio (w/c). Both of these have been shown to have a direct link to drag.
Now. The other two studies? The UK 1998 and US 1993 Miller Washington study? For the UK study, the information was listed in the legend. I presumed you would convert the values yourself. The US 1993 study however, had it’s measurements in the table presented. Though, the poor image quality is a bit of a problem. I have converted some of the essential things for you in the following sections below.
UK 1998 Study Measurements
Legend (that I posted in my post, that shows the value of the d (diameter)
So, the diameter is 3.7 inches, which means we can convert that to millimeters. The exact conversion is 93.98 mm.
But, I will admit – there is a distinct lack of mention of the thickness. But we can presume that it may be somewhere in the 0.5 mm to 1.5mm range which is common. We could presume a flat 1mm for simplicity’s sake. Measurements, are there however.
US 1993 Miller Washington Paper measurement table
The final study in that post, regarding drag reduction? I know the quality of the images was bad. But it said on the table that that all measurements are in inches. So the thickness of the lattice walls is 0.15 mm for the fins F1 and F2. 0.20 mm for F3, F4 and F6. For F5 it’s 0.3 mm.
Measurements, see at the bottom it says “all measurements in inches” (I apologize for the quality, once again!)
The AFIT study clarifies that the different lattices tested had a thickness ranging from: 0.177 mm, 0.101 mm and 0.177 mm – but keep in mind that the missile tested was 406 mm long. This is still proportionally quite small. Even if we assume a x3 scale up, the thickness (where the missile would be 1206 mm long) the fins would still be around 0.5 mm with how thick they are. I am unsure if a leading edge was utilized in the lattices.
It’s unfortunate that the 1998 UK study does not clarify how thick it was, and it does reduce it’s credibility in my eyes, somewhat. But it can be safe to presume it was probably a standard thickness in the 0.5 mm to 1.5 mm range. No leading edge was utilized in this test. The missile itself was around 1080 mm long.
Finally, the 1993 Miller Washington paper, the missile itself is 264.16 mm long – being even smaller than the AFIT one. The fins present have a thickness of 0.15 mm and vary up to 0.3 mm in total.
There. Now, I will repeat myself again: link the sources you have used on the subject, along with giving me measurements of the R-77 that you deem to be correct, and explain, why, they are correct.
Then just link them again, instead of doing whatever this is.
And I practically refuted this above. You shouldn’t just dismiss them because you failed/didn’t want to look at the measurement tables present in the documents because I forgot to link them in the thread in a way that you could digest at a glance.
As I’ve said before, link the discussion, sources and dimensions that you speak of, instead of arguing in bad faith against my points. I am willing to admit that I could be wrong, but the way you are exercising yourself in response to the theories I have regarding the subject is just ridiculous and lazy. You argue in bad faith, which makes anyone less likely to listen to what you have to say.
Having somewhat looked back on the discussion in this thread at a surface level; I would say that isn’t the first time you have done something like that in regards to debates of the subject. So, stop doing that.
Instead, and for a final time: list the all sources you have used, so people who are joining in on the conversation now can utilize them, provide the “correct” measurements of the R-77 and stop making a fool of yourself with your lazy, bad faith arguments, especially when the post in question had clear effort put into it.
You are not taking the high road by accusing me of building a strawman or arguing in bad faith when you have failed to concede that your point is argued on the basis of a few biased western studies.
I have already been made to restate some of these points over a dozen times I will not continue to do so.
…
Biased western studies? So are you implying that studies on aerodynamics have a political bias rooted behind them? Okay. Prove the bias, and link me the “superior” eastern sources then.
I just want it on record, YOU brought this up, not me. You accuse the studies of bias when I have presented you proof that they are not. This is a blatant, borderline extreme case of a strawman. I am not in the wrong for pointing out your logical fallacies. Along with that, you hit the ball home on multiple other logical fallacies such as:
Ad Hominem: You attack the sources, without actually refuting my argument, now that I reinforced my points
Poisoning the Well: Now that I reinforced my points, you instead seek to disvalidate Western sources as a whole – without little to any proof.
Burden of Proof: Once again, you are shifting the burden of proof; which you have done multiple times and I actually entertained you; I provided all my sources in detail. But now that it didn’t work? “Western Bias!”
You again, demonstrate that you have little interest to actually engage or debate the points I lay forth. Even though I complied with what you said in regards to the measurements.
This is ridiculous. I provided the sources I used, and now that I filled your additional demands – you once again move the goalpost on the completely unfounded grounds of “western bias”.
And now, I question your intentions very much, and I think this is bit of a “mask off” moment for you, considering you essentially discredit Western academia as a whole – with no proof whatsoever.
I am genuinely intrigued what you have to say now. In fact, I will be blunt and say I’ll flag this reply because of the implications it has. And I will also save this on the internet archive, so you won’t be able to wiesel your way out of any debate if this is brought up again in the future.
Again, link the sources you think are so much better on the subject. I, and everyone else here, is willing to read them, so do so!
Where does the mass export of the R-77 indicate that they are abandoning them? They have developed a model with planar fins - likely to take advantage of the lower RCS. Do you think they will abandon the previous models due to this? I don’t think so.
The existence of two models of the same missile concurrently indicates to me that they are just broadening their assortment of weaponry - already more comprehensive than any nation aside China.
No, I suspect you are not privy to this information.
The R-27R/ER is designed to hit a target maneuvering at 8G. It pulls 35G’s. The Phoenix is designed to hit a 6G target, it pulls 25G. 3x minimum required overload to effectively engage targets as a generic rule of thumb cannot be used to ascertain the maximum overload of a given ordnance.
Do you have a better source? How are nations like US, France, Germany, UK any more reliable?
I said nothing of politics.
How are unoptimized grids against optimized planar fins not biased in some manner?
That’s not ad-hominem.
I cast doubt on their validity from the start.
If I wait a year, post a single link to something and then contradict what you’ve said more than a dozen times should you be forced to consistently reply to the same dogma that has already been refuted?
Astute observation. Had you spent this time looking at earlier posts on this thread and the AMRAAM thread you would have come upon this very conversation no less than six separate times and with probably a dozen individuals involved.
I simply put that optimized grid fin data generally contradicts the sweeping statements you made, which is true even in your own studies. Grid fins are roughly equivalent to planar fins in subsonic and supersonic conditions, generally worse only in transonic region and when compared with zero AoA. They are superior in mid to high supersonic region.
Okay. And I said as much in that reply, and the one before and even on the one before that. I have repeatedly said that it could be the case. I just want a direct source on the matter.
My bad.
Look, I’m going to say this again, for the final time, provide sources or links to past discussions. I do not have a issue with your claims, I have an issue with the way you present them. You want me to take your word for granted, which isn’t going to fly.
When I replied to you initially, you doubled down on the same approach. That is the issue; which is why we are here. All you would have needed to do, was just tell me to go read the past conversations. Or given a link. That’s it.
But if it really is something you just cannot do, then I’ll go read the conversations myself – because it feels that you just don’t want to provide links to those conversations, when you could have saved all this time by doing just that. You shouldn’t assume that people have read the entire thread + a whole another one, especially if it has been going on for as long as this thread has.
Tbh, getting the R-77 to fly straight is bit of a tricky endeavor, but it could probably be done; just not sure how. Probably through some custom content. Might look into that myself – developing a tool for testing the missiles in-game could be worth while.
But idk, Gaijin is weird when it comes to accepting reports on stuff like that. I have a feeling you could post all the code you used to make the tool – and Gaijin would still reject it on some flimsy premise of “values not being obtained properly” or whatever.
i suspect that what you’re saying is completely incongruent with reality. what i said is undeniable if r37m was as effective as you claim russia wouldve achieved arial superiority years ago,
there were periods in time in which russia was firing like 5+ r37m a day. with a 80% success rate that wouldve destroyed the airforce of ukraine in around 2/3 weeks, its been 3 years.
thats WAYYY over what you would need to hit an 8g maneuvering target, stinger is rated for 8g maneuvering targets as an example. and the highest number you can find online is 25gs.
