GGTharos Posted December 30, 2015 Share Posted December 30, 2015 That's because drag forces are much lower at high altitude (40k), so the differences can be very subtle. nice, but pls read your own graph. The 530D does NOT bleed speed much faster than the AIM-7, it just start bleeding speed earlier. loss rate (and therefor the graph) is almost identical, just shifted by a few seconds, caused by longer burn time for the AIM-7. By this graph, nothing is wrong with the 530D [sIGPIC][/sIGPIC] Reminder: SAM = Speed Bump :D I used to play flight sims like you, but then I took a slammer to the knee - Yoda Link to comment Share on other sites More sharing options...
LuSi_6 Posted December 30, 2015 Share Posted December 30, 2015 So as I said, the cunclusion out of this graph is wrong, no matter if the graph itself is correct or not :pilotfly: Warthog HOTAS, Saitek Pedals, Oculus Rift :joystick: Link to comment Share on other sites More sharing options...
OxideMako Posted December 30, 2015 Share Posted December 30, 2015 Blade, the reason is due to how it's coded. The Cd curve for the 7M and 530D are quite similar, but the cross sectional area has been jacked to bigger than an AIM-54. This is what is causing it to slow down like a brick. That sounds like fixing that would solve most of the issues we are seeing discussed here. The question is how long ED are going to take to fix this. They have been incredibly slow when it comes to missile fixes, just look how long we have had the "missile guidance" issues... Link to comment Share on other sites More sharing options...
GGTharos Posted December 30, 2015 Share Posted December 30, 2015 The question is, can you convince them that what they chose to model is wrong? [sIGPIC][/sIGPIC] Reminder: SAM = Speed Bump :D I used to play flight sims like you, but then I took a slammer to the knee - Yoda Link to comment Share on other sites More sharing options...
RuskyV Posted December 30, 2015 Share Posted December 30, 2015 (edited) That could very well be true in the real world GGTharos. I'm just saying how it works in DCS. I have looked up the rocket motor burn times in missile lua and compared to the graphs posted here, and it starts to decelerate slightly when the second stage kicks in. I'm not sure if that happens on all altitudes, but it does happen in the charts blade posted above. Edit: I noticed, it only happens in blade's graph. In IASGATG it accelerates during the sustain stage. Maybe it does depend on altitude? If the AIM7m's sustainer is still active after the peak curve then this would explain the extended portion of where i've marked "aero drag" this could well be my misinterpretation of what is happening with this type of missile. This is where it becomes complicated because each missile is different and finding a direct comparison is tricky. I was half afraid of using another missile to show the difference in the fight dynamics over the 530D as the function of each missile is this different. My main question still stands in that i think there might possibly be a fundamental problem with the drag of the 530D missile. Referring back to the acceleration plot for that 530D (the first graph with time as the Y axis) im still not fully convinced that after the boost stage of its acceleration it should it be dropping off as quickly as it does especially not at 15.000ft ? Edited December 30, 2015 by (504)Blade Link to comment Share on other sites More sharing options...
OxideMako Posted December 30, 2015 Share Posted December 30, 2015 The question is, can you convince them that what they chose to model is wrong? You would think that drag would be the easiest thing to work out, given dimensions/shapes of missiles are nearly all publicly available, but even if we could convince them they are wrong, they will pull the "but it works at 40K ft+ and would overperform if we fix it for lower alts!" card. I get that doing this stuff is hard, and ED likely has lots of documents for various missiles, but there is no way on earth the Super 530D has more drag than an AIM-54. It sounds like they fudged the numbers in sim to meet the rough specs of the 530 to me. I trust IASGATG on this one, he has clearly spent a LOT of time researching this stuff. (just check out the missile mod!) Although I am sure you know that GG!:D Link to comment Share on other sites More sharing options...
Darkwolf Posted December 30, 2015 Share Posted December 30, 2015 Lets manufacture a tiny wind tunnel and scaled missiles :D [sIGPIC][/sIGPIC] PC simulator news site. Also....Join the largest DCS community on Facebook :pilotfly: Link to comment Share on other sites More sharing options...
Brisse Posted December 30, 2015 Share Posted December 30, 2015 Lets manufacture a tiny wind tunnel and scaled missiles :D Supersonic windtunnel! Woho!!1 :lol: Link to comment Share on other sites More sharing options...
GGTharos Posted December 30, 2015 Share Posted December 30, 2015 You would think that drag would be the easiest thing to work out, given dimensions/shapes of missiles are nearly all publicly available, but even if we could convince them they are wrong, they will pull the "but it works at 40K ft+ and would overperform if we fix it for lower alts!" card. No, drag is quite hard to work out, but there are guidelines. As for ED, sure, that's one thing. [sIGPIC][/sIGPIC] Reminder: SAM = Speed Bump :D I used to play flight sims like you, but then I took a slammer to the knee - Yoda Link to comment Share on other sites More sharing options...
IASGATG Posted December 30, 2015 Share Posted December 30, 2015 So as I said, the cunclusion out of this graph is wrong, no matter if the graph itself is correct or not I'd say in the 40kft case that the difference is minimal enough to be disregarded perhaps. Here is a 10kft M0.9 launch case. You'll notice the difference in rate is about 20%. You'll notice that the missile is worthless (Slower than Mach 1) after about 21s. This is also about 6nmi of travel. This makes the missile slightly longer ranged than the R-73 which sits at about 5nmi of travel before Mach 1 and makes those 5nmi in only 15s compared to the 530 needing 19 seconds to do it. Link to comment Share on other sites More sharing options...
GGTharos Posted December 30, 2015 Share Posted December 30, 2015 yes, fair enough - and yes, it does depend on altitude: The actual DRAG FORCE (not drag coefficients in this case) depends on air density. Drag coefficients depend on air density as well in some respect, as they are typically tied to a mach number (it's probably more complicated than that, but we really don't need to concern ourselves with that part) That could very well be true in the real world GGTharos. I'm just saying how it works in DCS. I have looked up the rocket motor burn times in missile lua and compared to the graphs posted here, and it starts to decelerate slightly when the second stage kicks in. I'm not sure if that happens on all altitudes, but it does happen in the charts blade posted above. Edit: I noticed, it only happens in blade's graph. In IASGATG it accelerates during the sustain stage. Maybe it does depend on altitude? [sIGPIC][/sIGPIC] Reminder: SAM = Speed Bump :D I used to play flight sims like you, but then I took a slammer to the knee - Yoda Link to comment Share on other sites More sharing options...
IASGATG Posted December 30, 2015 Share Posted December 30, 2015 I'd also like to point out we're comparing this to the in game AIM-7 which imo is performing about half as well as it should be anyway. Link to comment Share on other sites More sharing options...
sedenion Posted December 30, 2015 Share Posted December 30, 2015 The question is, can you convince them that what they chose to model is wrong? Seriously... the only comparison between AIM-54 and 530D is the fins global design, but the 530D is much more slim and as IASGATG says, its aerodynamic profile is designed to reduce drag at > mach speed... Link to comment Share on other sites More sharing options...
RoflSeal Posted December 30, 2015 Share Posted December 30, 2015 Makes no sense for Cross sectional area of Super 530D to be bigger then the AIM-54 S 530D AIM-54 Diameter 263mm 380mm Wingspan 620mm 910mm Link to comment Share on other sites More sharing options...
Exorcet Posted December 30, 2015 Share Posted December 30, 2015 Seriously... the only comparison between AIM-54 and 530D is the fins global design, but the 530D is much more slim and as IASGATG says, its aerodynamic profile is designed to reduce drag at > mach speed... Well the fact of the matter is, if you don't have a solid number to change things to, it's not much of an objective improvement. What I don't get it why ED doesn't seem to like CFD to fill in the gaps, which is what the entire missile mod thread was about as far as I know. Trying to fit missile performance to a few range/altitude points sounds like it might create room for error. Not having data on hand though, I can't really point to something and say it's better. Awaiting: DCS F-15C Win 10 i5-9600KF 4.6 GHz 64 GB RAM RTX2080Ti 11GB -- Win 7 64 i5-6600K 3.6 GHz 32 GB RAM GTX970 4GB -- A-10C, F-5E, Su-27, F-15C, F-14B, F-16C missions in User Files Link to comment Share on other sites More sharing options...
GGTharos Posted December 30, 2015 Share Posted December 30, 2015 Keep in mind that it is generally acceptable to increase drag for a missile that is subject to guidance induced flutters. However, you have to know that the missile does this. [sIGPIC][/sIGPIC] Reminder: SAM = Speed Bump :D I used to play flight sims like you, but then I took a slammer to the knee - Yoda Link to comment Share on other sites More sharing options...
sedenion Posted December 30, 2015 Share Posted December 30, 2015 Just some images... http://forums.eagle.ru/attachment.php?attachmentid=131656&stc=1&d=1451441072 Link to comment Share on other sites More sharing options...
RuskyV Posted December 30, 2015 Share Posted December 30, 2015 I was looking through the files in DCS and came across some performance related figures for the missiles and the 380d is defiantly not fudged with the phoenix data. its closer to the aim7 in size and weight compared to anything else I could see... I don't see the thrust from the missile being the problem either, I defiantly still think drag is to high for anything below 40kft. Link to comment Share on other sites More sharing options...
IASGATG Posted December 30, 2015 Share Posted December 30, 2015 Cross sectional area is greater than aim54. Cd and Cl curves are slightly increased aim7 curves. Link to comment Share on other sites More sharing options...
Brisse Posted December 30, 2015 Share Posted December 30, 2015 Cross sectional area is greater than aim54. Cd and Cl curves are slightly increased aim7 curves. With cross sectional area, you mean the one ED describes as "-- characteristic square (характеристическая площадь)"? Tried changing that from 1.2 to 1.0 which is just in between the AIM-54 and AIM-7 (1.1 and 0.9). That seemed to have given the Super 530D some more range. I can now hit head on Tu-142 (Mach 0.5 10000m ASL) out to 45km which is actually slightly beyond the "wikipedia-range" of the Super 530D. On the other hand, most other missiles will also extend beyond their "wikipedia-range" when I put them through the same test. For example, the AIM-120B I managed to score a hit at almost 100km (wiki-range: 55–75km):) Link to comment Share on other sites More sharing options...
IASGATG Posted December 30, 2015 Share Posted December 30, 2015 That is what I mean Brisse. I've just done 4 test shots at 10kft at M0.9 with AIM-7M, Super 530D, Super 530D with the AIM-7 characteristic square and then finally the 530D with my missile mod applied to it. Link to comment Share on other sites More sharing options...
LFCChameleon_Silk Posted December 30, 2015 Share Posted December 30, 2015 from what I understand the 530D performs better at higher altitudes and 10k is kinda low, so if your getting huge boost at low altitudes better check the missile mod at 40k launch and make sure the thing isn't going 150km :P Link to comment Share on other sites More sharing options...
Brisse Posted December 30, 2015 Share Posted December 30, 2015 make sure the thing isn't going 150km :P It self destructs long before that :) I think it's set to 50 seconds self destruct. Link to comment Share on other sites More sharing options...
RuskyV Posted December 30, 2015 Share Posted December 30, 2015 Cross sectional area is greater than aim54. Cd and Cl curves are slightly increased aim7 curves. I must be looking at the wrong data lol :) Link to comment Share on other sites More sharing options...
RuskyV Posted December 30, 2015 Share Posted December 30, 2015 That is what I mean Brisse. I've just done 4 test shots at 10kft at M0.9 with AIM-7M, Super 530D, Super 530D with the AIM-7 characteristic square and then finally the 530D with my missile mod applied to it. this seems to be more in the right ballpark, really informative stuff mate! Link to comment Share on other sites More sharing options...
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