Phantom vs XXX

[Hummingbird]

Kermit I am very interested in seeing some papers to explain these "unexpected phenomena" you're talking about, because the well known coanda effect isn't one of them. 

As for the Cl/Cd graph I just showed you, it's from flight testing, and there are load factor charts there to compliment them:

(full line is with slats, dashed line is without )

 

To get back to what started this whole debate, your claim that these devices shouldn't improve STR is false, pure and simple (as can be seen pretty clearly from the charts above). That's what Sgt. Pappy is trying to get you to understand, whilst you seem to want to avoid it at this point.

And the positive effect on STR (& ITR) isn't unique to the F-4, you see it on the performance graphs of all such equipped fighters (Sgt Pappy already refered you to the F-14 as another clear example), all the way back to WW2 where some of the first to enjoy these benefits were the Messerschmitt 109 and 262, which is what prompted North American to copy the design for their F-86. In short there's a good reason these devices and/or derivatives there'of have been used on a lot of fighter designs since then.

Edited May 27, 2022 by Hummingbird

[LanceCriminal86]

I think I like hearing more about why things work the way they do and from actual F-4C/D/E pilots about the differences of how the hard wing and slatted jets flew than pointing at performance charts.

[SgtPappy]

10 hours ago, LanceCriminal86 said:

I think I like hearing more about why things work the way they do and from actual F-4C/D/E pilots about the differences of how the hard wing and slatted jets flew than pointing at performance charts.

That's the thing, we have plenty of that here/in other threads which were mentioned already but Kermit didn't seem to believe them at first.

So Hummingbird posted data that is in line with what the pilots have mentioned. Nothing better than data to back up anecdotes from real aircrew, right?

Edited June 2, 2022 by SgtPappy

[Dragon1-1]

TBH, if the charts were disagreeing with real aircrew, I'd probably lean towards believing the charts. Here, though, they agree. Even if there were some initially unexpected vortex shenanigans with the flaps (and there might have been, aerodynamic are weird sometimes), they produced the results qualitatively matching the expectations.

[303_Kermit]

On 6/2/2022 at 4:28 PM, SgtPappy said:

That's the thing, we have plenty of that here/in other threads which were mentioned already but Kermit didn't seem to believe them at first.

So Hummingbird posted data that is in line with what the pilots have mentioned. Nothing better than data to back up anecdotes from real aircrew, right?

 

Church is a place to "belive". Not aerodynamics.
Here is a nice article and film about how the vortexes I talk about are created. There's an airfoil moving up and down, and of course it's about Karmans vortex:

https://fyfluiddynamics.com/2015/10/flow-visualization-can-be-a-valuable-tool-for/?doing_wp_cron=1654384116.9519119262695312500000

By high AoA the vortexes are created. On the film you may see Vortexes building up on upper (and lower) surface and sliding down along the airfoil. They are not "static"- so they're not the one I wrote about. The Vortex I'm talking about is more complicated. Another example here.
https://www.iahrmedialibrary.net/the-library/methods-in-hydraulics/fluid-mechanics/flow-induced-vibrations-karman-vortex/270

There's more about it in NACA reports, I'll try to find something more precise soon. 
Here is another visualization of Vortex - also not static. but it gives a good idea what I'm talking about
 

 

Please pay attention, that in spite of having laminar flow on the upper surface, the airflow is far from nice pictures you're all accustomed to. 

Here are 2 traces of static vortex 2:33 the vortex builds in the corner , is barely visible, and the flow is in different direction ,but that is actually static vortex. It'looks like that:
https://www.iahrmedialibrary.net/the-library/methods-in-hydraulics/fluid-mechanics/flow-separation/272
 

Here is also example of Static vortex, but it's just a foto: 

These vortex is very small. But it's the same principle. It makes the shape of a solid (here's a car) more "aerodynamic" . Vortex itself consumes very little energy from the flow, and works positive. These vortexes may build up also on the trailing part of the flow and they usually lower the drag.
The Vortex on Phantom was huge, and grows bigger after flaps were extended. I shall search for films of Phantoms in foggy or rain conditions - it may create a visualisation sometimes.

 

One more thing. These time no vortexes. Look how the flow of fluid (the air is also a fluid in aerodynamic sense) changes only because of different speed. Thats Reynolds number. If you're inpatient move to 4:30 and enjoy.
https://www.iahrmedialibrary.net/the-library/methods-in-hydraulics/fluid-mechanics/stratified-flow/939

 

I'm not saying that charts presented above are fake or incorrect. I'm trying to say, that interpretations of them, and possible connection(s) between STRT and Slats are beyond subjects possible for you to determine here. Not because you're not intelligent, but because you need far more data to definitely answer the question. And in first case, you don't even know what data you need to be able to specify a full and correct answer, because it's far more complicated than you think.

 

With my best regards
303_Kermit

 

PS. @Hummingbird I may provide more information in any subject connected to fluid mechanic and aerodynamic, but I'd like to make it on prv. I'm not sure if everything I have I can legally publish. I'm terribly sorry

Edited June 5, 2022 by 303_Kermit

[SgtPappy]

22 hours ago, 303_Kermit said:

Church is a place to "belive". Not aerodynamics.
Here is a nice article and film about how the vortexes I talk about are created. There's an airfoil moving up and down, and of course it's about Karmans vortex:

https://fyfluiddynamics.com/2015/10/flow-visualization-can-be-a-valuable-tool-for/?doing_wp_cron=1654384116.9519119262695312500000

By high AoA the vortexes are created. On the film you may see Vortexes building up on upper (and lower) surface and sliding down along the airfoil. They are not "static"- so they're not the one I wrote about. The Vortex I'm talking about is more complicated. Another example here.
https://www.iahrmedialibrary.net/the-library/methods-in-hydraulics/fluid-mechanics/flow-induced-vibrations-karman-vortex/270

There's more about it in NACA reports, I'll try to find something more precise soon. 
Here is another visualization of Vortex - also not static. but it gives a good idea what I'm talking about
 

 

Please pay attention, that in spite of having laminar flow on the upper surface, the airflow is far from nice pictures you're all accustomed to. 

Here are 2 traces of static vortex 2:33 the vortex builds in the corner , is barely visible, and the flow is in different direction ,but that is actually static vortex. It'looks like that:
https://www.iahrmedialibrary.net/the-library/methods-in-hydraulics/fluid-mechanics/flow-separation/272
 

Here is also example of Static vortex, but it's just a foto: 

These vortex is very small. But it's the same principle. It makes the shape of a solid (here's a car) more "aerodynamic" . Vortex itself consumes very little energy from the flow, and works positive. These vortexes may build up also on the trailing part of the flow and they usually lower the drag.
The Vortex on Phantom was huge, and grows bigger after flaps were extended. I shall search for films of Phantoms in foggy or rain conditions - it may create a visualisation sometimes.

 

One more thing. These time no vortexes. Look how the flow of fluid (the air is also a fluid in aerodynamic sense) changes only because of different speed. Thats Reynolds number. If you're inpatient move to 4:30 and enjoy.
https://www.iahrmedialibrary.net/the-library/methods-in-hydraulics/fluid-mechanics/stratified-flow/939

 

I'm not saying that charts presented above are fake or incorrect. I'm trying to say, that interpretations of them, and possible connection(s) between STRT and Slats are beyond subjects possible for you to determine here. Not because you're not intelligent, but because you need far more data to definitely answer the question. And in first case, you don't even know what data you need to be able to specify a full and correct answer, because it's far more complicated than you think.

 

With my best regards
303_Kermit

 

PS. @Hummingbird I may provide more information in any subject connected to fluid mechanic and aerodynamic, but I'd like to make it on prv. I'm not sure if everything I have I can legally publish. I'm terribly sorry

 

This is really interesting stuff! I'm definitely going to save the videos in my documents..

But dude, we have agreed a long time ago. There's nothing you are saying that we do not agree with. The issue is you seem to be focusing on these vortices but the argument was about something totally different.

For the third time: Your original position that slats do not increase STR has been disproven with aerodynamics, data and anecdotes. Not some blind faith. Then you changed the topic into talking about vortices which is something else that no one else is disputing.

Edited June 5, 2022 by SgtPappy

[303_Kermit]

Probably the reason for my hysteria is because It is a Phantom.... I wait for it since i'm 12 and I played F16 Fighting Falcon on C64.... I waited so long. I hope he will be perfect. So I can uninstall all other modules (except of UH-1)

Edited June 5, 2022 by 303_Kermit

[SgtPappy]

44 minutes ago, 303_Kermit said:

Probably the reason for my hysteria is because It is a Phantom.... I wait for it since i'm 12 and I played F16 Fighting Falcon on C64.... I waited so long. I hope he will be perfect. So I can uninstall all other modules (except of UH-1)

 

Honestly I know how you feel! I can't remember the last time I was THIS crazy about anything.

We're all united on this front at the very least

[Nexus-6]

5 hours ago, 303_Kermit said:

Probably the reason for my hysteria is because It is a Phantom.... I wait for it since i'm 12 and I played F16 Fighting Falcon on C64.... I waited so long. I hope he will be perfect. So I can uninstall all other modules (except of UH-1)

 

Like the Tomcat, the Phantom is going complete a lot of wishlists and answer of lot of questions.  Thanks to Heatblur's efforts, I've learned more about the F-14 in the last two years than I have in the last thirty, and I fully expect their F-4 module to be no different.

[Hummingbird]

On 6/5/2022 at 1:22 AM, 303_Kermit said:

I'm not saying that charts presented above are fake or incorrect. I'm trying to say, that interpretations of them, and possible connection(s) between STRT and Slats are beyond subjects possible for you to determine here. Not because you're not intelligent, but because you need far more data to definitely answer the question. And in first case, you don't even know what data you need to be able to specify a full and correct answer, because it's far more complicated than you think.

I'm going to answer you here with a simple; No.

Look I studied fluid dynamics for several semesters before ultimately selecting a different direction due to a lack of relevant (to me) aeronautical industries (and thus interesting jobs) in my country, so I know my way around a lot of theory in its subdisciplines hydro- & esp. aerodynamics, and can thus tell pretty well when people are talking sense in that regard. So far you've yet to show a single unknown or "unexpected" phenomenon induced by slats unique to the F4 in your posts, not one.

Finally I'm not the one concluding that the slats on the F4 were the direct reason behind the improved STR & ITR performance (although that should be rather obvious via method of exclusion), it's carved out in the actual report. 

So I'm sorry Kermit, but I don't buy it.

Edited June 7, 2022 by Hummingbird

[303_Kermit]

hic acurem aqua, hic aqua revertitur.

 

With my best respect

Edited June 7, 2022 by 303_Kermit

[Lurker]

So just to get this thread back on topic, I'm gonna go out on a limb and say, all things being equal (including pilot skill) if say an F4-E and a Mig23 (insert best air to air variant here) were to meet, the F4 would absolutely demolish the Mig23 in WVR combat

[Dragon1-1]

Yeah, a Me-262 could probably clean the MiG-23's clock in WVR, too.  As I said before, it really wasn't the world's greatest dogfighter. Great interceptor, can chuck its Fox 1s quite well in BVR, just don't try to turn with anything smaller than a bomber.

A more interesting matchup will be MiG-19 vs. the Phantom. That one turns exceedingly well, but isn't anywhere near the Phantom when it comes to engine power.

[Lurker]

Yup, I know. But there are a lot of people who think that the Mig23 > Mig21 just because 23 > 21  As for a Me-262 vs Phantom, yeah well, that's kind of pushing it

[WinterH]

"Fanboys" of both aircraft claim theirs win by far, but I personally believe F-4, especially E with slats, will considerably more often come out on top in WVR engagements vs MiG-23. Perhaps not MLD, but even that is a question mark, and we are not supposed to get a MLD module anyway.

As with of military hardware "lore", MiG-23s being completely unmaneuverable is not entirely the truth. If you look at the numbers, they can, in fact, have pretty damn good ITR and STR by 3rd gen fighter standards. Thing is, they get those in specific wing sweeps, which is a manual effort to choose unlike a Tomcat for example. And each sweep angle is a compromise. Also, especially the earlier ones were notorious for really, reeaaally not liking doing high AoA things, and, apparently, would promptly stop playing! So I personally thing with the MLA we will get, it is supposed to be less about MiG-23 completely being unable to WVR, but more so that it is a really though and demanding job to get the best out of it in that regime. Then, there is the fact that it has a fairly atrocious canopy. That coupled with a full time job of flying it well enough, would make the MiG pilot more likely to lose tally I would think. I'm not under any illusions that Phantom will have anything remotely like carefree handling either, but MiG is just so much more notorious for that, and it has more things to fiddle with to keep it perform in a dogfight.

Looking at the weapons for WVR, guess it will depend on what Sidewinders we will get to a degree. AFAIK, 9L and M weren't a thing on regular F-4Es, especially not in 80s. Though, I don't think there is a reason for us not to get 9P5s, which aren't as agile but are still all aspect. Otherwise, R-60Ms can be an advantage for the MiG, if it can get its nose to where it'll achieve a lock. As for the earlier Sidewinders, late Atolls are roughly equivalent anyway. Also, while they take 4 seconds to achieve a lock and launch, later Sparrows can actually be pretty decent in WVR due to their quick acceleration and big control surfaces. Well, potentially anyway, we'll see. And R-24s should be about as good there too probably, also with an all aspect IR option.

I really think it will be an interesting dynamic with MiG having a better radar and arguably better (but fewer) missiles for BVR, while the Phantom being better for WVR. Also, Phantom will have countermeasures, but MLA normally shouldn't unless Iraqi field modifications is chosen, which had some. So that will be mission/server dependent.

Then there'll be Mirage F1, existing MiG-21Bis and F-5E, upcoming stuff like F-8 and hopefully eventually MiG-17F, Mirage III... going crazy with excitement here!

[Dragon1-1]

On 6/8/2022 at 1:53 PM, WinterH said:

Thing is, they get those in specific wing sweeps, which is a manual effort to choose unlike a Tomcat for example. And each sweep angle is a compromise.

The problem is not manual sweep control, the problem is being unable to do it. MiG-23 cannot move its wings when pulling over 4G, it has to unload to do it. That means that you basically have to set "optimum wing sweep" at the start of the fight, and pray that you can get the kill before you get out of envelope for this particular angle. If you can't, turn rates go to pot, and you have to unload for long enough for the wings to move. This is a massive disadvantage that plays a big part in why the MiG-23 just wasn't the right choice for dogfighting. You could, to some extent, but from level merge it'll probably lose more often than not. 

EDIT: Had the load limit wrong, it has to unload to 4G. Still not too good.

Edited June 11, 2022 by Dragon1-1

[Vampyre]

18 hours ago, WinterH said:

 

Looking at the weapons for WVR, guess it will depend on what Sidewinders we will get to a degree. AFAIK, 9L and M weren't a thing on regular F-4Es, especially not in 80s.

Regarding the AIM-9L/M, the F-4E (both Standard E and DMAS birds) definitely had them in the late 80's. You see the CATM's for the missiles appearing in photos in 87-88 so it isn't out of the realm of possibility on them first being incorporated on the F-4E sometime in the mid 80's timeframe. Of course, Navy and Marine F-4J/N/S Phantoms got them in the late 70's (L) but they were still doing fleet air defense as their primary mission in Navy air wings. That combined with the need for the Air Force to equip its most modern air superiority platforms with the AIM-9L/M first means that the Air Force F-4's being mainly interceptors and fighter/bombers had to wait for the better missiles to trickle down to them... and someone had to use the large stocks of older/modified missiles that had not yet expired. The AIM-9P-4 and P-5 missiles were upgraded AIM-9J/N/P missiles that incorporated either the AIM-9L (P-4) or AIM-9M (P-5)  seeker heads. The F-4E wasn't toothless when it came to all aspect heat seeking air to air in the 80's. I would hazard a guess that the F-4E was capable of using the L/M much earlier than 86/87 but those missiles were only being issued to F-15 and F-16 wings at the time. The DCS mission editor allows us to limit the use of these weapons as the mission maker sees fit for simulating earlier time periods where these weapons are out of place. I for one am looking forward to some 3rd gen tail chasing dogfights.

[_BringTheReign_]

5 hours ago, Vampyre said:

The DCS mission editor allows us to limit the use of these weapons as the mission maker sees fit for simulating earlier time periods where these weapons are out of place.

This is best way to implement imo! If it carried them at some point, it's good to add them, and then mission makers and server owners can decide for themselves which time frame/loadouts they want to allow/restrict. 

[Ravenus]

What is this talk about the F4E spanking the mig 23 ML in WVR? There is some huge misconceptions about the reality of the ML's capabilities. The Mig had better turning capability, depending on which wing sweep was used. The evaluation testing in cope peg etc.. were done at the recommended 45º angle. At the 16º sweep and below a certain speed, the mig spanks the F4. Furthermore, the testing was made on the previous unreliable versions, M, MS etc.

The big caveat to all of this is how fast the wings could switch from one sweep angle to another and how ergonomical it would be in a dogfight scenario (which I don´t know)

I suggest looking at this comparative report : Compared Air Combat Performances Mig-23ML versus F-4E  by Topolo. Not 100% accurate but in the ball park. It´s a treat

 

 

EDIT : I just saw G.J.S. post on his real life experience. Interesting insight on how vis and handling hindered the on paper performance potential of the ML

 

 

Edited June 11, 2022 by Ravenus

[bies]

10 hours ago, Ravenus said:

The big caveat to all of this is how fast the wings could switch from one sweep angle to another and how ergonomical it would be in a dogfight scenario (which I don´t know)

MiG-23 didn't change wing sweep angle during maneuver air combat due to severe G limitations during the wing sweep change process, it would need to fly nearly straight for several seconds. The full wing transfer took about 18 seconds, a little less when retracting the wing, which was helped by the incoming air flow during the backward stroke.

Overall MiG-23 will be very challenging to model correctly as it behaved very differently depending on wing sweep, with many distinct quirks in all 3 planes controll and stability, it will be practically 3 flight models, i hope RAZBAM will nail it.

With 45° MiG-23ML is very close to F-4E with both instantenous and sustained turn rates. Both F-4 and MiG-23 will require some serious piloting skills to BFM efficiently, nothing like F-16 or F/A-18 pulling full stick to turn. From MiG-23ML manual:

[Dragon1-1]

1 hour ago, bies said:

MiG-23 didn't change wing sweep angle during maneuver air combat due to severe G limitations during the wing sweep change process, it would need to fly nearly straight for several seconds. The full wing transfer took about 18 seconds, a little less when retracting the wing, which was helped by the incoming air flow during the backward stroke.

Actually, it could be pulling 4G, and from 45 to 16 degrees it'd only take about half the time it'd takes for full transfer. Still, being stuck at 4G for 8-9 seconds is still forever in a dogfight, but it might be doable if the fight goes slow and you're not pulling a whole lot of G, anyway. Of course, the MiG will likely be defensive by then.

[WinterH]

14 hours ago, Ravenus said:

The big caveat to all of this is how fast the wings could switch from one sweep angle to another and how ergonomical it would be in a dogfight scenario

Answer is pretty simple: 9.5 out of 10, they just can't be changed to another position in a dogfight. In my post from Wednesday, I had a vague recollection of wings not being sweepable past very low G loads, and them taking a while to change position even then, but wasn't entirely sure so didn't write anything about that. Then posts from Dragon1-1 and Bies fairly specifically added this to the conversation too.

Basically you set the wings to 45 position before the fight, and forget about it most of the time, with all the benefits and vices of that position. Unless the fight happens at/devolves into really slow speeds, MiG-23 will remain at 45 degrees, which, as far as I know, is in the ball park of F-4E's turning capability, but then it will lose its main party trick: the insane acceleration. Also, all the way before the latest MLDs with an additional dogtooth at wingroots and leading edge slats, MiG-23s hated pulling AoA with a passion. Add on top the canopy situation, and you lose most of the on paper good looking dogfighting potential. The legend and lore goes that most operators preferred MiG-21 over the 23 when it comes to dogfighting, but I'll admit that's anectodal.

Not saying Phantom will be incomparably better or anything, and it will be hard to fly in a dogfight itself anyway, but I feel like it'll come out on top 6-7 out of 10 in WVR.

[Hummingbird]

The slatted F-4E shouldn't be that difficult to BFM in. Sure at very high AoA rudder will be needed for rolling, but you get used to that rather quick, as with the F-14.

 

[Koty]

On 6/16/2022 at 3:36 PM, Hummingbird said:

The slatted F-4E shouldn't be that difficult to BFM in. Sure at very high AoA rudder will be needed for rolling, but you get used to that rather quick, as with the F-14.

 

Did some reading couple days back, the AE slats should to a large extent fix the aileron reversal issue. But tame in this context probably meant F-14 levels of tame.

That said, there is no need to "believe" what the comparative performance is. Numbers tell us that with 45° sweep, they will be very closely matched. If you really want to game the Phantoms, push the sweep selector out of the detent to about 30-35° and rate at 7G's.

[Gwalker99]

on the Mig 21... Stay 450 .. and never pull more than 5-6 G's  and maneuver changing vectors  ... the 21 cannot keep up without losing TONS of energy..then when the 21 is SLOW, put your nose on him and kill  never go nose low though to let the 21 pick up speed.... that was what John Boyd said