A-A Missiles drag and lift

[85th_Maverick]

As an aerodynamicist myself, I found the new AIM-120 behaviour to be quite unrealistic. I mostly agree with 85th_Maverick 's points but I would like to add a possible explanation about the first real life aim-120 kill, which seems to match the current AIM-120 model on DCS.

The rocket motor was still burning at the time of impact, meaning that some of the centripetal force needed to turn is actually given by the motor, and not just the fins. The CFD study I found online about the new aim-120 for DCS states that the maximum AOA is 30 degrees, its thrust would be 16700 N and its weight around 150 kg (at launch); while using this data it appears obvious that as soon as 30 degrees AOA is attainable (you don't need to be in steady state flight for this), the missile could turn at 50 g's!!! Which is even above the airframe limit. This means that the real missiles steer mostly in the first second of flight, this is why the real missile hit that MIG-25, not because it had God-level lift. I have personally witnessed (in game) an AIM-120 pulling 14 g's at mach 1.2 while losing speed almost at the same rate as an afterburning fighter. THIS IS INSANE.

 

Hello "Stefasaki",

 

I'm very pleased to hear of another real world (not CFD blind believer) aerodynamicist who can also look into it and discuss about it! Indeed, as you state, the lift = resultant forces perpendicular to the undisturbed airflow vector, therefore although we're used to call the lift as the result of airflow to airframe interactions alone (through the developed pressures field around the aircraft, excluding that affected by the propulsion system), most of the aircraft are obtaining their lift as the vectored sum of forces perpendicular to the "infinite upstream" airflow. But, even with the high lifting component generated by the AIM-120's thrust will NEVER be enough to make the missile out turn a 9G turning fighter at speeds below 1300 to 1200 km/h IAS, and I mean it! Just a simple but correct and verifiable algebra calculation can reveal that. Right now, if I come to landing with my A-10 at about 260km/h (140KIAS) I can see an AIM-120B flying right by me in the same direction but a bit slower without falling yet (I can reproduce it if someone really wants to see it for sure)!

 

I do respect these guys trying to find the unknown using only CFD, but they're kind of trying to find something in the dark with flashlights on their foreheads but having them turned off (their common sense and logic is turned off). They will absolutely not be able to obtain the correct results using only CFD models! I'd like to cite a much elder colleague of mine who has experienced the results for thousands of wind tunnel tests through decades of carrer at the high speed wind tunnel: "Whenever I have finished a test run, gathered all the data and plotted the wind tunnel corrected (final) results for all the 6 aero coefficients, everytime I have a sense of doubt whether they are the real ones or not, but seeing these folks doing CFD tests only and believing even the first results they come up with, although they'll later use different initial equations and obtain way different results than the first and still want to believe they've done the right job..., it leaves me speechless of what they actually understand about the airflow in general!" I honestly can't add more to what that experienced man had to say.

 

How the AIM-120B is now modeled in DCS, I can say that it has just slightly higher than appropriate critical AoA of 28 instead of around 24.5, but the maximum lift coefficient is incredibly high (roughly double) at around 1.5 as I can see it being given in the missiles data file. Just 15% more and the CL max of this AIM-120B's wings (fins) would have the F-16's CL max for which the wings have droops and LERX. This is total nonsense, but..., sooner or later the people will realize it! Normally the MIG-21's whole wing-body combination won't prove more than 0.9 as CL max which occurs around 21..22 AoA, yet these aerodynamically ugly fins that the AIM-120B has with somewhat reduced aspect ratio, flat plate type airfoils, higher sweep and mathematically zero taper should mostly produce 0.8, but in DCS..., 1.5, lol!

 

Now that I have replied to you, colleage in the same science, I want to address the following to every CFD enthusiast here (I'm also one, but I'm more careful at choosing right from wrong) that uses only CFD and hoping to obtain simulation data to use for DCS:

 

I honestly consider that the person in charge of doing aerodynamic analysis MUST always have a bit of experience with direct wind tunnel models, see for himself how the numbers usually get for various 2D wings (airfoils) or whole wings and aircraft mock-ups, see how the coefficients (lift, drag, moments) and critical angles tend to vary, including varying airspeed, for different but same airfoils from root to tip, different wing sweeps, different wing mounting types (high, mid or low wing), different taper ratios and the most important of all, different aspect ratios. Only after they have passed a bit through that and see a lot of real results for many types of real models they are much less likely to get fouled by unreliable CFD results. Next to the elder aerodynamicist bureau there was also a CFD department and even the leading person, a very experienced guy with lots of math and physics "onboard" (his knowledge) said that although they use a quite fine and well balanced mesh (to be effort effective) and sometimes even played with different types of mesh models in order to replicate similar tests that were conducted in the real tunnel, they were sometimes getting resultant forces 1.5 to 3 times different (as high as 200% error in other words) than the real resulted forces for various angles of attack tests. Most of the time, the lift errors were not due to an unrealistically determined lift slope (CL to AoA derivative) by the CFD, but by the quite erroneous CL0 (which we use to name the zero AoA lift coefficient) and the usually too high determined airflow separation/reversal aerodynamic angles (AoA and Beta). In some cases the CFD considered that the model won't find it's stall AoA until some 35-40 was reached, while the real model already stalls at 20..21. These are the stories of CFD limitations and they're not stopping here.

 

Kind regards!

Edited April 10, 2020 by 85th_Maverick

[dundun92]

Hello "Dundun", I don't know what do you mean by ASE/ASEC (sorry I don't know all the acronyms), but as I've replied before, in order to get better results, we should try to simulate the same conditions as in that footage using only the circles displacement reference instead of the radar antenna reference while keeping all the other conditions similar and you'll get more reasonable to believe results than thinking that you can fire a missile from that altitude, closure rate, vertical displacement and offset angle (12 to 15 degrees given only by the radar antenna indication) and hit something. It won't work even with this exaggerated amraam lift that we in DCS today, which should be enough to tell that something's absurd!

Sry, should have explained, the ASEC (Allowable Steering Error Circle) is the big circle that moves relative to the aircraft pitch, and the ASE (Allowable Steering Error dot) is the little circle that represents the optimal steering. My point was that matching the circle alignment would not do you much good, because you have to assume that the algorithms used to calculate their positions is the same IRL and in DCS, otherwise youre not comparing equal shot parameters.

[Exorcet]

I do respect these guys trying to find the unknown using only CFD, but they're kind of trying to find something in the dark with flashlights on their foreheads but having them turned off (their common sense and logic is turned off). They will absolutely not be able to obtain the correct results using only CFD models! I'd like to cite a much elder colleague of mine who has experienced the results for thousands of wind tunnel tests through decades of carrer at the high speed wind tunnel: "Whenever I have finished a test run, gathered all the data and plotted the wind tunnel corrected (final) results for all the 6 aero coefficients, everytime I have a sense of doubt whether they are the real ones or not, but seeing these folks doing CFD tests only and believing even the first results they come up with, although they'll later use different initial equations and obtain way different results than the first and still want to believe they've done the right job..., it leaves me speechless of what they actually understand about the airflow in general!" I honestly can't add more to what that experienced man had to say.

With all due respect to your friend, that's an issue with the engineers and not CFD. CFD is as much a tool as a wind tunnel, which has its own problems.

 

 

ED needed data to build a better missile and they went the CFD route probably because it's a million times easier to doing a flight test program with a physical AIM-120 model. I doubt that they could perfectly match the AIM-120 given their goal (to model the missile for a consumer flight sim) but what we have should be a fairly good representation of the missile. CFD is a proven tool and while it can't be trusted blinded, it also shouldn't be discarded blindly because it disagrees with your common sense.

 

 

 

 

How the AIM-120B is now modeled in DCS, I can say that it has just slightly higher than appropriate critical AoA of 28 instead of around 24.5, but the maximum lift coefficient is incredibly high (roughly double) at around 1.5 as I can see it being given in the missiles data file. Just 15% more and the CL max of this AIM-120B's wings (fins) would have the F-16's CL max for which the wings have droops and LERX. This is total nonsense, but..., sooner or later the people will realize it! Normally the MIG-21's whole wing-body combination won't prove more than 0.9 as CL max which occurs around 21..22 AoA, yet these aerodynamically ugly fins that the AIM-120B has with somewhat reduced aspect ratio, flat plate type airfoils, higher sweep and mathematically zero taper should mostly produce 0.8, but in DCS..., 1.5, lol!

If you disagree, are you able to run your own simulation perhaps? If so perhaps you could correct what you consider methodology errors on ED's part and show us what the missile should actually do. A casual comparison to a completely different airframe isn't really the most solid ground to stand on.

[nighthawk2174]

AIM-120A (as I did a bit of searching I concluded that most BVR missiles weight about half after depleting their propellant) that needs to fly straight for less than a second (it's logically not programmed as a sidewinder to start turning just 2-3 meters after coming off the rail)

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I know in the sparrow at a range of under 5 miles the safety distance is significantly decreased. I see no reason the AMRAAM doesn't have a similar feature.

 

Sorry to say, but that's something only out of HAWX or probably ACE COMBAT,

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Try BMS which as far as i'm aware used CFD for their missiles and at this point 5 different pilots that I know of have all said BMS is quite good but still a conservative estimate of its performance. The missile will hit in game not so currently in DCS although I wonder how much of that is due to poor guidance in DCS rather than lift now.

 

So it can't be that the target was 12..15 degrees up when the F-16 fired the missile from 300KIAS,

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Your going to have to prove this against the F16's radar scope... good luck with that.

 

The more reliable data that I consider worth for our discussion is the HUD like information show on the same monitor as the radar data. If you'd wanna replicate the same conditions by using only the relative position between the smaller interception circle next to the AIM-120's type circle, you will have a much lower and reasonable angular displacement through which the R-27ER will also have the needed room to maneuver and correct it's interception path.

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As said above you can't rely on the ASE in DCS as its not programmed the same as the IRl one.

 

(0.4 squared is used in the AIM-120C's data)

(0.5 squared being used in the data file)

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These numbers as far as I can tell are not sref/weted area. For example the value for the sidewinder is .35, while the phoenix is 0.9, super530D is 1.1, and the maverick is .8. None of these line up with sref's at all.

 

are around 2 times greater the regular ones they both should have. For instance, in the "missiles_data.lua" file, the AIM-120C must have a maximum aerodynamic lift coefficient of 0.7..0.71, while the AIM-120B must have it at 0.73 in order to have the missiles start falling at the correct IAS.

?

 

If you disagree, are you able to run your own simulation perhaps? If so perhaps you could correct what you consider methodology errors on ED's part and show us what the missile should actually do. A casual comparison to a completely different airframe isn't really the most solid ground to stand on.

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+1

[stefasaki]

Right so ...

 

 

 

 

Not sure how you came up with this. There's no 50g required here.

 

 

 

 

I'm looking at a graph of empirically collected fly-out vs available g data right now, and yep, 14g at 1.2 might be a little high at that speed. But only a little. Depends on altitude and specific missile, including control setup. It is quite far from being insane.

First thing, if a bridge constructor told you that a particular bridge doesn't look safe wouldn't you at least listen to him? and yes, 50 g are not required, my point is exactly that, you can steer using thrust if you have it, and absurd turns are possible if employed correctly. You don't need an incredible amount of lift to do that, hence you can achieve a hit like in the first reported real life aim-120 kill.

 

Second thing, the insane thing about that situation was the insignificant energy loss, what is more insane if you want is their subsonic behaviour (I would design airliners like an aim-120 if that were to be true) and their capability to pull 30 g only using lift at 15000 ft at Mach 1.6.

 

As a last statement, i find your attitude to be wrong in a constructive environment, please consider being more flexible. Thank you

[GGTharos]

First thing, if a bridge constructor told you that a particular bridge doesn't look safe wouldn't you at least listen to him?

 

I'd look up his credentials, and I mean, while I don't need such a thing here you're not telling me anything that affects my life either.

 

and yes, 50 g are not required, my point is exactly that, you can steer using thrust if you have it, and absurd turns are possible if employed correctly. You don't need an incredible amount of lift to do that, hence you can achieve a hit like in the first reported real life aim-120 kill.

 

Second thing, the insane thing about that situation was the insignificant energy loss, what is more insane if you want is their subsonic behaviour (I would design airliners like an aim-120 if that were to be true) and their capability to pull 30 g only using lift at 15000 ft at Mach 1.6.

 

As a last statement, i find your attitude to be wrong in a constructive environment, please consider being more flexible. Thank you

 

A lot of research was done to tune these missiles. A lot of work, too. There are weaknesses in the missile FM (various iterations of it) that are known as well. So, after years of this, you come here making claims and offering no work. I'm not saying that you need CFDs or anything like this, I just don't see even any minimal testing of missiles to offer a counter to how they are tuned.

Edited April 16, 2020 by GGTharos

[stefasaki]

I am sure that a lot work is being done, but the newsletter from ED states that the previous study was primarily about finding a realistic zero lift drag value, not maximum lift, so ED itself doesn't claim to have the perfect model. I did my work, i used my expertise to report a bug. CFD is a complex tool, you could make a washing machine fly with the wrong assumptions, i am sure they will get to a good model with time. Up to a few months ago the aim-120 was a damn dart, and I am pretty sure that some work produced that model too. I provided some sort of solution: focus on the dynamics of the early stages of flight. And I am sure they are doing that as I read on the newsletter that they are looking for pitching moments and pitch stability (not previously done before), which for sure will greatly increase the accuracy of the simulation. Tell me what "work" should I do .... I do not work for ED, I have my own problems

Edited April 17, 2020 by stefasaki
Typos

[Noodle]

As entertained as I am by multiple wall-o-text posts from theoretical experts trying to explain how something we have video of happening didn't really happen...I dont have anything to add.

 

Except that the first SPLASH call came about 5 seconds after the FOX call, not 9 seconds as claimed. Which makes it that much more difficult to take seriously any of the other "evidence" written here.

[85th_Maverick]

Sry, should have explained, the ASEC (Allowable Steering Error Circle) is the big circle that moves relative to the aircraft pitch, and the ASE (Allowable Steering Error dot) is the little circle that represents the optimal steering. My point was that matching the circle alignment would not do you much good, because you have to assume that the algorithms used to calculate their positions is the same IRL and in DCS, otherwise youre not comparing equal shot parameters.

 

Totally agree, but then isn't the algorithm that calculates the displacement between the 2 circles the same for the DCS F-16 as in reality? I consider that the algorithm should be logical as it only tells me which direction should I fly in 3D in order to have my path intercept that of the target at any instant moment and if I continue on that course I will eventually collide with with the target. Isn't that the logic of the small circle? Cause afaik, that's not for the missile, but for my plane's target interception solution.

[85th_Maverick]

With all due respect to your friend, that's an issue with the engineers and not CFD. CFD is as much a tool as a wind tunnel, which has its own problems.

 

Sorry to contradict you, but the wind tunnel is more of a scientific and true results gathering tool, than a CFD model which is a very cheap way of getting a good gross idea of how the airflow wants to develop, but NOT the right tool to gather to trust into if you plan to gather the most correct results! That's a fact and not by someone's will (FAA or EASA) to drain money out of your pocket, you're forced by laws to use real wind tunnel test results for a particular aircraft that you intend to build or modify! Couldn't they let you use just CFD and that would be it? Well, it seems that they won't let you do it for proven reasons! And that's because even with the latest CFD models, the results are still not satisfactory! Yes, both the CFD and the wind tunnel have their own deficiencies, but after you do the right corrections (walls, dimensions ratios between those of the tunnel and those of the model, Reynolds, Mach, wake, etc. etc. corrections), the tunnel resulted values you'll always get you more precise results for any configuration and situation! Using pure CFD, the results are closing in (yet still not as precise) to the real ones only for a given set/range of conditions, while anything outside those conditions will have your CFD results (lift, drag, moments versus AoA and beta) go more and more erroneous, and not by just a little! No matter how well you set the original conditions (equations used and mesh design), in the end it won't make any difference whether you're an engineer who has experience with real test results as well as a good sense for the right results and who also masters CFD or simply someone who learned and mostly knows CFD without little aerodynamics knowledge! They will both get about the same best CFD results, so it's not the engineer's fault at using it right, nor the CFD bound user at using it right. It's just the CFD's limitations that won't let you get everything you want out of it and as such it should mostly be used for predictive flow patterns and how the aero forces tend to grow, but less (if not excluding) for actual maximum lift coefs, stall AoAs and complete drag functions. I must admit that there are 2 useful exception for which the CFD seems to own it's greatest trust as it usually goes hand in hand with real data. That usually happens at low AoAs, normally below 8..5! Anything above that would start getting you off-track in divergent manner! The lift slope (lift vs AoA), the viscous and resulted drag coefs function as well as the minimum drag coef can be acceptably fair and may be used as an initial or predictive data out of most CFD analysis. That's merely your best benefit of resulted forces out of a CFD. The moments otherwise, are not so lucky! Even at low or close to null lift AoAs, the moments are still something that you must consider getting from true tests, if..., you want something good!

 

ED needed data to build a better missile and they went the CFD route probably because it's a million times easier to doing a flight test program with a physical AIM-120 model.

 

Copy that! I agree that it's the most cost-effective method, but..., they should consider the above limitations if they also want it realistic and not worse than it was by default (2 years ago let's say)! On the other hand I disagree that it's very expensive to try making a 3D print of each missile model out of the cheapest material, yet strong enough to resist low speed bending moments, in order of at least 50 newton meters. For gathering an acceptably more precise CL max, stall drag, stall AoA and Cm vs AoA functions for the model, it would be grossly enough if they'd resume to a 50 or 100km/h undisturbed airflow. Even those results would be a lot more accurate than what we see now! These coefficients as well as the critical AoA won't vary wildly with airspeed (between a high aspect ratio glider and a slender missile) between a very low Mach number (say 0.01) and Mach 0.3 near SL, especially for the missiles that we mostly debate here regarding their maximum lift coef! Indeed, the CL max and critical AoA will be growing from say 5km/h up to around 370km/h IAS or Mach 0.3 at sea level (usually this gives you a peak of the best performances) with the lift slope remaining relatively the same (almost no increase), but that maximum CL and crit AoA growth is not so outstanding and you can extrapolate the very low speed functions to more precisely predict what would happen up to Mach 0.3 where the peak takes place. To give you a hint, usually the CL max and crit AoA at mach 0.3...0.4 are 12% higher, so grossly multiplying your very low Mach or airspeed maximum CL with 1.12 would give you a relatively fair distribution. This won't give you the best, but this is better than nothing for the start. Between 0.3 and up to critical Mach, the lift slope will start increasing exponentially (the power is realistically somewhat lower than 2), but due to the constantly and more rapidly degrading critical AoA, the maximum CL eventually decreases towards crit Mach. (the greatest loss taking place due to normal shocks stall). For predicting what happens there, I wouldn't recommend CFD, but validated equations that can better estimate your numbers there. Idk about the latest uber duper CFD programs that use other fundamental algorithms, such as Lattice-Boltzmann theories, no longer the old Navier-Stokes models, so maybe they can also give you some right lift/drag vs AoA functions for both transonic and supersonic, at least for the low AoA range, but I wouldn't be naive to go with just that.

 

I doubt that they could perfectly match the AIM-120 given their goal (to model the missile for a consumer flight sim) but what we have should be a fairly good representation of the missile. CFD is a proven tool and while it can't be trusted blinded, it also shouldn't be discarded blindly because it disagrees with your common sense.

 

Consumer flight sim, I agree..., but, even for a consumer dump, "not know much" player, having a high wing loading missile still fly with 1G lift force at some 280km/h IAS, that will hurt the eye even for the most noob guy! Seriously, at some point, even common sense will start ringing on you!

 

If you disagree, are you able to run your own simulation perhaps? If so perhaps you could correct what you consider methodology errors on ED's part and show us what the missile should actually do. A casual comparison to a completely different airframe isn't really the most solid ground to stand on.

 

I agree, but that's not the kind of answer for someone trying to point out that something's not correct as long as he knows it can still be corrected, which in the end is beneficial for everyone! If I'd ever do that (to try making my own flight sim) I wouldn't do it to persuade those who'd use it and tell them it's realistic! No! I'd do my best to validate what I'm doing for myself, make it as accurately as my money can help, but also open minded and patiently listen to what the others have to say! Who knows how someone can help me spot something, no matter how full of knowledge I can be, as there is always the possibility of having gaps in what I know, while a fresh set of eyes and mind, even with little knowledge can make me realize that there's something wrong after sharing me the tiniest detail that something could be wrong! That would put me on guard and have me trying to solve true from false solutions. I could actually be learning until I die and will never completely understand what I wanted (this happens as a fact for everyone), but I'll do my best to at least learn more and correct (there are many who understood/learned things wrong) and find ways to get the best out of my effort! If I'm an egocentric and stupid and force my own will onto what the other should believe, by telling him something like: "What I give you is right and don't question it", it's only a matter of time until the truth starts emerging and I won't save my unfair gained reputation for too long with that!

[85th_Maverick]

As entertained as I am by multiple wall-o-text posts from theoretical experts trying to explain how something we have video of happening didn't really happen...I dont have anything to add.

 

Except that the first SPLASH call came about 5 seconds after the FOX call, not 9 seconds as claimed. Which makes it that much more difficult to take seriously any of the other "evidence" written here.

 

When did I say that what happen didn't happen? Why are you trying here? I've only said that something doesn't add up if you'd take only the radar data reference from that footage and said that the HUD type data references seem to be the more and probably only reliable data! So, by your logic and what you say, the target wasn't just slightly above the F-16's longitudinal axis when he fired the missile, which happens if I replicate it using the circles displacements and target range before launch, but some very high above the HUD position (at some 12 degrees up giving the radar data) and when he shot the missile from 2.5nm, the missile not only had to compensate for the lagg after launch (this is not an AIM-9X, but a poor AIM-120 A actually), but also had to instantly turn close to an AIM-9X to intercept that Mach 1.4 target in thin air. That makes a lot of sense to you, does it? I don't need to reply to you again if that's the case, you'll probably understand it yourself sooner or later!

 

Regards!

[85th_Maverick]

Second thing, the insane thing about that situation was the insignificant energy loss, what is more insane if you want is their subsonic behaviour (I would design airliners like an aim-120 if that were to be true) and their capability to pull 30 g only using lift at 15000 ft at Mach 1.6.

 

Well, guess what! They have inputted almost ZERO drag increase with AoA. That's their "very realistic missile" energy loss! About the high altitude low mach (for a missile) insane g-load, you can rapidly calculate the lift coefficient for a conventional reference are of 0.127m^2 (not 0.05 as I quickly stated at the beginning) if the missile's weight gets to 109.5kgs (all fuel burned). You'll be surprised that they've made it at least triple =)) of what this should regularly be. Seriously, have a check for it!

 

As a last statement, i find your attitude to be wrong in a constructive environment, please consider being more flexible. Thank you

 

Welcome to DCS forums, where you'll get ridiculed in the most unimaginable ways if you dare say that something's wrong...! They are the boss..., you do as they say! You'll get it over time!

Edited May 10, 2020 by 85th_Maverick

[85th_Maverick]

I know in the sparrow at a range of under 5 miles the safety distance is significantly decreased. I see no reason the AMRAAM doesn't have a similar feature.

 

Copy that Nighthawk! I love having a decent conversation, even if contradictions can naturally occur in order to be debated! So, as you say it, the amraam also has a similar feature (yet we probably can't know the minimum safety distance), then probably the pilot might've launched the missile from further than 2.5nm at that 1200KTS closure head on. Idk, there's that possibility and then, the radar antenna indication wouldn't be erroneous in that footage, but there's something else we miss. The amramm, as you've said, even with the tremendous lift that has been inputted to it now, still passes behind the target unable to intercept it, so, should we increase the lift to even more absurd? It's obvious that something else is actually missing and we tend to accept something absurd here! How can we be sure that the video-voice timing isn't matching? If we could ever have the opportunity to talk with that pilot in particular and ask those important details from him, we'd be very happy to say the least, until then, we can more or less accept something more obvious from something too far stretched to be right!

 

Try BMS which as far as i'm aware used CFD for their missiles and at this point 5 different pilots that I know of have all said BMS is quite good but still a conservative estimate of its performance. The missile will hit in game not so currently in DCS although I wonder how much of that is due to poor guidance in DCS rather than lift now.

 

I had since 2006 and still do so up to this day, and not for the graphics, you can be sure! I understand that they've also relied on CFD, but, somehow their missiles have more natural drag with AoAs, more realistic max ranges and speeds vs altitudes, and not to mention the lift, which seems pretty spot on for what Mav-JP has done!

 

Your going to have to prove this against the F16's radar scope... good luck with that.

 

Yeah, hehe, well, that's why I wonder if not the launch distance or launch angle is wrong from as from what we consider. Again, an amraam couldn't do that sharp turn like an AIM-9X. Facts about their goal and design tell that radar guided missiles aren't meant for being maneuverable (they are much less maneuverable than short range missiles).

 

As said above you can't rely on the ASE in DCS as its not programmed the same as the IRl one.

 

Then we have way too less debatable data from that footage (just unreliable) for our discussion in this case!

 

These numbers as far as I can tell are not sref/weted area. For example the value for the sidewinder is .35, while the phoenix is 0.9, super530D is 1.1, and the maverick is .8. None of these line up with sref's at all.

 

Yes, I deduced that those are not the actual conventional reference areas of the real missiles to be used for aerodynamic calculations, but as they affect the actual lift/drag of the missile, then the Cy0 values must be set accordingly in order to obtain the right result (lift and/or drag) that you would obtain using the conventional reference areas for lift and drag for an according lift and/or drag coefficient.

 

There's a lot that I'd like to discuss with you regarding my personal work as I looked into this! I'm only positively looking for the better of this sim, not the worse! Hear later.

 

Regards!

[nighthawk2174]

When did I say that what happen didn't happen?

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Well you are the one arguing what we see in the tape can't have happened... that the radar must be wrong in someway.

 

HUD type data references seem to be the more and probably only reliable data!

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lol wut XD just because the radar video disproves your "common sense" doesn't make it wrong.

 

So, by your logic and what you say, the target wasn't just slightly above the F-16's longitudinal axis when he fired the missile, which happens if I replicate it using the circles displacements and target range before launch...

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Can't do this in DCS I don't know why this is so hard to understand that how both the circle and steering dot are programmed isn't the same as IRL!!!! Hec its even marked as bugged and WIP by ED.

 

...but some very high above the HUD position (at some 12 degrees up giving the radar data) and when he shot the missile from 2.5nm, the missile not only had to compensate for the lagg after launch (this is not an AIM-9X, but a poor AIM-120 A actually), but also had to instantly turn close to an AIM-9X...

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yup and it did

 

to intercept that Mach 1.4 target in thin air.

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more like .85'ish Mach actually.

 

That makes a lot of sense to you, does it?

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yup

 

then probably the pilot might've launched the missile from further than 2.5nm at that 1200KTS closure head on. dk, there's that possibility and then, the radar antenna indication wouldn't be erroneous in that footage,

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doesn't matter what you think he fired at under 2.5NMi.

 

so, should we increase the lift to even more absurd?

[/Quote]

No the remaining factors are probably related to safety distance, guidance algorithms, and pitch moments/max aoa. Before this change it would miss by even more than it does now.

 

that the video-voice timing isn't matching?

[/Quote]

Well thankfully the radar provides a hint:

the T on the right wall below the closure rate represents the TTG. Now i'm not 100% sure if this indicator appears right when the missile comes off the rail or after after the safety distance but that doesn't really matter as it indicates the video and voice are in sync.

 

Yeah, hehe, well, that's why I wonder if not the launch distance or launch angle is wrong from as from what we consider. Again, an amraam couldn't do that sharp turn like an AIM-9X. Facts about their goal and design tell that radar guided missiles aren't meant for being maneuverable (they are much less maneuverable than short range missiles).

[/Quote]

 

LOL again

A) Good luck proving the radar is somehow wrong?

B) You don't need a 9X in this situation.

C) Really, and what in their design says they can't turn well?

D) I mean if you look at what I originally posted with how a sidewinder given the same nose cone and similar fins to a 120 became substantially more maneuverable, plus as the footage shows the amraam is in fact a very maneuverable missile.

Edited May 11, 2020 by nighthawk2174

[Airhunter]

 

I am very curious how the R-27 will perform once ED updated them, they said they want to work on the R-27 this month.

 

Cut to 3 months later and still not even AMRAAM changes and the ever so promised new missile API. The new API is really where it's at since we need more complex proortional navigation guidence and terminal criteria. Thw 27 fam. does need a CFD rework like the AIM-7 and 120.

[deadpool]

We did a BVR training this weekend and I just want to take the missile shots from that and put it into a wall of text. I understand that this thread is about drag and lift, so the Flightmodel ...

 

But the guidance is a joke as well. It's as if the AIM-120 (and I hear the Phoenix is using the same base "AI"?) is really absurd.

While I can only estimate how close this is to reallife, I would fear for NATO pilots if this is close to the truth.

[TAW_Blaze]

...

 

Consumer flight sim, I agree..., but, even for a consumer dump, "not know much" player, having a high wing loading missile still fly with 1G lift force at some 280km/h IAS, that will hurt the eye even for the most noob guy! Seriously, at some point, even common sense will start ringing on you!

 

...

 

Cut to 3 months later and still not even AMRAAM changes and the ever so promised new missile API. The new API is really where it's at since we need more complex proortional navigation guidence and terminal criteria. Thw 27 fam. does need a CFD rework like the AIM-7 and 120.

 

We did a BVR training this weekend and I just want to take the missile shots from that and put it into a wall of text. I understand that this thread is about drag and lift, so the Flightmodel ...

 

But the guidance is a joke as well. It's as if the AIM-120 (and I hear the Phoenix is using the same base "AI"?) is really absurd.

While I can only estimate how close this is to reallife, I would fear for NATO pilots if this is close to the truth.

 

All you guys must be new here, there has been basically no change in missile guidance since the beginning of FC3 minus the APN update which is a fairly simple change of a 3 breakpoint table gain instead of a single value. The FM changes are cool but when my missile starts actively avoiding the target in terminal phase what does it matter?

 

At least now we know something is in the works in the background.. for the last decade there has been absolutely nothing, I cannot comprehend how a supposed "air combat simulation" blatantly ignores any improvement of completely insane missile behavior that is one of the #1 defining factors when it comes to actual combat. Instead we have more maps and worthless modules with no environment to play in. Great.

 

There are myriads of other small issues that would've only taken a little bit of attention to bridge to something that isn't completely silly. For instance most FC3 aircraft can very often survive frontal missile hits and continue to fire and guide both IR and radar guided missiles despite their radar and/or complete weapons system probably being damaged beyond use and also the pilot most likely being killed in the process (albeit this happens sometimes). It would not have been necessary to have a completely revamped super-duper state of the art damage model to fix this, but rather with some basic scripting to disable certain functions in the jet as a placeholder until a generic solution is available. This seems to be better addressed in FF modules (although I did not specifically test), however for instance this has been an issue that basically plagued some aspects of combat since quite frequently you ended up getting traded by a guy who was essentially dead when he started shooting back. Yet completely unadressed for over a decade. This is my problem. Completely immersion and realism breaking issues go unnoticed and ignored for essentially infinite time.

 

Honestly feels like a storefront simulator. Looks very shiny on the outside but once you start looking inside you discover the mess. I'm not saying *certain other simulators* do a perfect job of simulating every single particle, but they tend to have a better approximation of the end result. However this idea seems to have escaped DCS completely.

 

/Rant

[kdubz]

All,

 

First off, DCS is an amazing product. It is extremely complex and always getting better. I applaud the developers / programers working diligently to make things better. Since there is a huge disparity in BVR missle capabilties, why not set them as equal and see who the better tactician is with their airframe? (Think Stock car racing) This would make PVP much more enjoyable instead of getting shwacked by a AIM-54 at 30nm. (There is a reson these are not in the inventory anymore and I love nastalgia.) Of course, DCS cannot keep up with all of the missile types and modeling changes with actual intel, this would provide an equal playing field for all. I can elaborate further if required.

 

I know each ariframe is different, but the DLZ for example in the F-16 gives no credit for loft. In fact the ASC is often at the bottom of the ASE when the adversary is above you. As you climb in altitude the DLZ "grows" and RPI occurs at a longer range. 30 - 40NM is standard range for the first SOO. The current AIM-120 model doesnt get close to that even at 40k and 1.3 mach. Like in real life, the missles operate differently than many of the DLZ's are modeled and this is also true in the sim, so the aircraft dont need to be perfect.

 

I am hoping for a more level playing field knowing this is a sim and a great one at that. This would allow the powers at be to focus on aircraft improvements and bug fixes and not have to be intel experts modelling missile flyouts. Creating a few classes of BVR missiles would work as well. Keep up the great work and send spears!

 

- Just a thought from some random fan.

 

v/r,

 

kdubz

[AeriaGloria]

Wouldn’t updated DLZ Solve your problem? It’s easy for a mission designer to give both sides the same types or balance

[GGTharos]

I am hoping for a more level playing field knowing this is a sim and a great one at that.

 

Give everyone the same air-frame and weapons and there's your playing field - already available within the game.

[kdubz]

Give everyone the same air-frame and weapons and there's your playing field - already available within the game.

 

 

Thanks. The issue is the actual missile performance in game. An AIM-54 vs an AIM-120 is the example I gave. The WEZ in the jet is just style points. Having the missile actually fly and function at real unclassified ranges is what needs to happen. Since one developer can make a missile work better than the rest regardless of actual missile performance is the problem. This leads to the numerous folks flying F14’s and J11s because they can exploit the issue I just mentioned.

 

 

Sent from my iPad using Tapatalk

[AeriaGloria]

What missile on J-11 works better then it’s suppossed to? I still think that’s for the mission designer, if it was last patch I would say mod every missile to be the same....

 

And as far as I can tell the Phoenix is most unrealistic in the limited guidance API that should be overhauled soon as it works in MP

[GGTharos]

I'm not getting your example. If you want a level playing field, same air-frames, same weapons. Missiles ARE different IRL and should be different in sim. Even if they fail to correspond completely to what's known about them, the entire idea of a sim vs 'just a game' is that you adapt to those differences and adjust tactics.

 

 

So I also don't get your 'better tactician' comment either, given that multi-aircraft tactics depend on understanding your weapons, the other guy's weapons, and how that information ties in together with air-frame capability to counter specific threats with specific tactics ... as opposed to what you appear to be proposing which is same tactics for everyone/everything.

 

 

The basis of all tactics is already the same and you appear to want to remove variety from this, but maybe I misunderstand.

 

 

 

Thanks. The issue is the actual missile performance in game. An AIM-54 vs an AIM-120 is the example I gave. The WEZ in the jet is just style points. Having the missile actually fly and function at real unclassified ranges is what needs to happen. Since one developer can make a missile work better than the rest regardless of actual missile performance is the problem. This leads to the numerous folks flying F14’s and J11s because they can exploit the issue I just mentioned.

 

 

Sent from my iPad using Tapatalk

[deadpool]

All you guys must be new here, there has been basically no change in missile guidance since the beginning of FC3 minus the APN update which is a fairly simple change of a 3 breakpoint table gain instead of a single value. The FM changes are cool but when my missile starts actively avoiding the target in terminal phase what does it matter?

 

At least now we know something is in the works in the background.. for the last decade there has been absolutely nothing, I cannot comprehend how a supposed "air combat simulation" blatantly ignores any improvement of completely insane missile behavior that is one of the #1 defining factors when it comes to actual combat. Instead we have more maps and worthless modules with no environment to play in. Great.

 

There are myriads of other small issues that would've only taken a little bit of attention to bridge to something that isn't completely silly. For instance most FC3 aircraft can very often survive frontal missile hits and continue to fire and guide both IR and radar guided missiles despite their radar and/or complete weapons system probably being damaged beyond use and also the pilot most likely being killed in the process (albeit this happens sometimes). It would not have been necessary to have a completely revamped super-duper state of the art damage model to fix this, but rather with some basic scripting to disable certain functions in the jet as a placeholder until a generic solution is available. This seems to be better addressed in FF modules (although I did not specifically test), however for instance this has been an issue that basically plagued some aspects of combat since quite frequently you ended up getting traded by a guy who was essentially dead when he started shooting back. Yet completely unadressed for over a decade. This is my problem. Completely immersion and realism breaking issues go unnoticed and ignored for essentially infinite time.

 

Honestly feels like a storefront simulator. Looks very shiny on the outside but once you start looking inside you discover the mess. I'm not saying *certain other simulators* do a perfect job of simulating every single particle, but they tend to have a better approximation of the end result. However this idea seems to have escaped DCS completely.

 

/Rant

 

I know about the history, but I chose not to accept it as an excuse to keep going on like that.

 

I do agree with the rest of what you said 100%.

 

And congratulations on your new position!

 

All,

 

First off, DCS is an amazing product. It is extremely complex and always getting better. I applaud the developers / programers working diligently to make things better. Since there is a huge disparity in BVR missle capabilties, why not set them as equal and see who the better tactician is with their airframe? (Think Stock car racing) This would make PVP much more enjoyable instead of getting shwacked by a AIM-54 at 30nm. (There is a reson these are not in the inventory anymore and I love nastalgia.) Of course, DCS cannot keep up with all of the missile types and modeling changes with actual intel, this would provide an equal playing field for all. I can elaborate further if required.

 

I know each ariframe is different, but the DLZ for example in the F-16 gives no credit for loft. In fact the ASC is often at the bottom of the ASE when the adversary is above you. As you climb in altitude the DLZ "grows" and RPI occurs at a longer range. 30 - 40NM is standard range for the first SOO. The current AIM-120 model doesnt get close to that even at 40k and 1.3 mach. Like in real life, the missles operate differently than many of the DLZ's are modeled and this is also true in the sim, so the aircraft dont need to be perfect.

 

I am hoping for a more level playing field knowing this is a sim and a great one at that. This would allow the powers at be to focus on aircraft improvements and bug fixes and not have to be intel experts modelling missile flyouts. Creating a few classes of BVR missiles would work as well. Keep up the great work and send spears!

 

- Just a thought from some random fan.

 

v/r,

 

kdubz

 

 

First off, DCS is an amazing product. It is extremely complex and always getting better. I applaud the developers / programers working diligently to make things better. Since there is a huge disparity in airframe capabilties, why not set them as equal and see who the better tactician is with their forces? (Think Chess) This would make PVP much more enjoyable instead of getting shwacked by a hornet at 180kt. (There is a reson these are soon not in the inventory anymore and I love nastalgia.) Of course, DCS cannot keep up with all of the aircraft types and modeling changes with actual intel, this would provide an equal playing field for all. I can elaborate further if required.

 

I know each ariforce is different, but the IRIAF for example in the F-14 gives no credit for service life. In fact the failure rate is often at the peak of the comparison when the adversary is way below you.

 

I am hoping for a more level playing field knowing this is a sim game and a great one at that. This would allow the powers at be to focus on engine improvements and bug fixes and not have to be intel experts modelling aircraft flyouts. Creating a few classes of aircraft would work as well. Keep up the great work and send spears!

 

- Just a thought from some random fan.

 

 

Above text slightly altered by Deadpool to fit the bill.

Edited May 26, 2020 by deadpool

[TotenDead]

Give everyone the same air-frame and weapons and there's your playing field - already available within the game.

 

Useless irony. Planes shouldn't be the same, shouldn't have same characteristics. But they should be competitive enough or there won't be any interest in playing anything except some offline stuff. MiG-29A vs F-18C is not competitive, and you can easily see that people prefer more capable jets because noone likes to suffer. If you think that forcing mission creators to give blue planes for each side so that the game could be somewhat not one-sided is a nice idea then you probably live in some other world than me and most of online players.