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Flight model of my dreams


TheBigTatanka

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21 minutes ago, TheBigTatanka said:

It is indeed more draggy with 2 bags and a 5x1 loadout. On an 80nm commit, i was just able to break mach 1 by the time I was ready to shoot floggers at ~35nm and 36k feet. Previously, i would be around 1.1 or 1.2 mach at that point. Not complaining though, the jet really feels better in all regimes. I too hope it's all accurate, but that's for more physics minded people than me to figure out. Glad we've got the updates we got anyway.

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Indeed. I remember the first update a good while back when the Hornet first got its more realistic pylon drag implemented... and I wasn't happy. 🙂 After that initial, "What did they do?" moment, I felt good about them getting closer to real-world for sure. 👍

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11 minutes ago, wilbur81 said:

Indeed. I remember the first update a good while back when the Hornet first got its more realistic pylon drag implemented... and I wasn't happy. 🙂 After that initial, "What did they do?" moment, I felt good about them getting closer to real-world for sure. 👍

You have no idea what dynamic thrust is. Example: A F110-GE-129 at sea level Mach 0.8 produces 35000 lbs of thrust, almost twice as much as a F404-GE-402 produces at the same condition.

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Edited by karasawa
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On the all the cruise issues, the lift slope has changed. Pre patch 2 tanks at 30000+ ft 500 knots sat around 5 degrees AoA. Now it's around 7. You will notice this at any loadout. 1 tank 6 AAM went from 3ish to 5 or something, with a few hundred PPH more fuel usage.

I don't have data on what is correct, but the F-16 really struggles with two tanks now, such that it has to fly lower and burn more fuel, negating the extra fuel capacity.


Edited by Exorcet
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Let's keep it civil here, it's not reasonable to tell people they have no idea about this or that. We're all collaborating on a cool project here, it's not a contest of wills. That shuts down people's willingness to share what they do know.

I wonder how we can check that cruise AOA against known data.

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5 hours ago, wilbur81 said:

This is probably ED getting a more accurate pylon/stores drag model on the Viper. The Hornet in this little test mission I created before yesterday's update has a better than 1:1 thrust to weight over the Viper's only 0.75:1 (the weights of both jets are shown in the screenshots attached).  The Viper achieved Mach 1 in the exact same amount of time (32 seconds from mission start with full A/B and altitude hold, at the same altitudes and starting airspeeds) as the Hornet that had thrust to spare. Additionally, the Viper achieved a maximum speed of Mach 1.26 while the "slicker" Hornet only achieved Mach 1.2. Again, the Lot 20 Hornet's two F404-402s produce a total of 35,400 lbs of thrust while the Block 50 Viper's F110-GE-129 only produces 29,499 lbs of thrust. It sounds like they have gotten the drag values more realistic for the Viper.... but I've yet to test my attached mission on yesterday's new update. 

 

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ViperHornet TtoW (1).miz 7.58 kB · 0 downloads

 

Your thrust to weight ratios are wrong to begin with. Also if you look at the history of super cruise you will find a little surprise that completely debunks your  strange claims.

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26 minutes ago, Blinky.ben said:

Your thrust to weight ratios are wrong to begin with. 

Did you read read my post and look at the screenshots carefully?

image.png


Edited by wilbur81

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3 hours ago, karasawa said:
3 hours ago, karasawa said:

You have no idea what dynamic thrust is. Example: A F110-GE-129 at sea level Mach 0.8 produces 35000 lbs of thrust, almost twice as much as a F404-GE-402 produces at the same condition.

 

 

 

Sorry, man... I'm clearly a very simple man and I'm just not following you when GE themselves say their engine produces 29000lbs at Sea Level. Not sure what else to say there...though I could understand that thrust 'class' certainly could just be an "averages" way to talk about a more dynamic thing. They certainly could market their engine better by going with your dynamic numbers of 35K lbs at Sea Level. 🙂

As to drag indexes of 50, "speed has almost nothing to do with T/W ratio," etc.... T/W has everything to do with speed, as long as drag doesn't over-compensate for thrust. The EM charts, as far as I'm aware, don't give you the three-bag, six-missile type info. So, drag index of 50, M1.9 capable - My questions: Does a Viper with three full bags and six Aim120C's (two of which are on the wingtips) have a Drag index greater or less than 50? Or, put another way: are you claiming that the Viper will do M 1.9 in the configuration shown in my example above?  ED clearly doesn't believe so... for good reason. 

I'm not sure if you've ever read Hasard Lee's account of taking a completely clean Viper on a top speed run, but here's a brief excerpt:

"Despite a significant amount of thrust still coming from the engine, the drag at 1.9 Mach [at 35K feet] caused the jet to rapidly decelerate, pushing me forward until my shoulder-harness straps locked."

https://www.sandboxx.us/blog/this-is-what-its-like-to-take-an-f-16-to-the-absolute-limit/

And finally, Karasawa... I'm not quite sure what to make of your private message to me that stated: "Hi, thank you for these info. A 402 powered hornet should perform very closely to a viper." Are you using a different persona on the Public forums from your Private Messages?

I'm just a bit confused, which I know you're very comfortable pointing out. 🙂 

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Edited by wilbur81

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15 minutes ago, Blinky.ben said:

I read the original post wrong. I was taking it as the real life viper only had a .75/1 ratio.

Gotcha... no worries. 👍 Wasn't quite sure what you were referring to with the Cruise missile allusion, but the A model Hornet could Super Cruise in certain configs. Though not as sleek as the Viper, the clean Hornet can get movin' a bit as well.

 


Edited by wilbur81
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Did a couple of tests at 25 and 30k altitude....read left to right (altitude, mach, ag ordinance, t2 (2 wing tanks) p31 (tgp) hts ecm long pod, then a2a ordinance, longs are 120c short 9x, then fuel flow pounds per hour..... used burner to .88 or .9 ish mach then mil power...then fast fowarded (straight and level)

viper_metrics.png


Edited by Carbon715
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@karasawa What config would make up a DI of 50? 2 tanks 2 Aim-120s?

With the top graph you posted it should be fairly easy to verify the sim performance by testing that it can reach the max altitudes shown for each GW in Mil.

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14 hours ago, karasawa said:

F/A-18 has higher zero lift drag coefficient (0.024 vs 0.0175) and more reference area (400 sq ft vs 300 sq ft), making F/A-18's total level flight drag 80% higher than that of the F-16.

So the question is, will F-16's external tanks and AA missiles increase the drag by 80%? Probably not.

I think you may have done your math in the wrong direction for the Hornet's drag. Assuming the numbers below from this NASA testing (which are pretty much the ones you cited above, the Hornet has 20% higher Zero-lift Drag than the Viper, not 80%. Again, I think you just took your math the wrong direction. 

image.png

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10 minutes ago, wilbur81 said:

I think you may have done your math in the wrong direction for the Hornet's drag. Assuming the numbers below from this NASA testing (which are pretty much the ones you cited above, the Hornet has 20% higher Zero-lift Drag than the Viper, not 80%. Again, I think you just took your math the wrong direction. 

image.png

Oh boy, that is zero lift drag coefficient, not drag. You need to multiply it by the wing area. 

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Why are you only multiplying the ZLD CoE by wing area when fighters get lift (and drag) from the other parts of the aircraft (including stores and pylons that may or may not have been hanging for these various tests?  And what is the drag index loadout for 50 on the Viper? 

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vor 59 Minuten schrieb wilbur81:

Why are you only multiplying the ZLD CoE by wing area when fighters get lift (and drag) from the other parts of the aircraft (including stores and pylons that may or may not have been hanging for these various tests?  And what is the drag index loadout for 50 on the Viper? 

Google HAF F-16 supplement manual. It has drag indexes and EM charts for the 229 and 129 engine, but it is not allowed to post links to the manual here. It also has max AB accelerations. There are plenty of sources, just google a bit. It ain't classified afaik.
The readings I got are quite accurate.
Also, the landings speeds are now according to the manual.
That and the now matching turn rates (didn't test that part really, but there were plenty of tests and tacview and stuff) do indicate that we do have a flight model that is probably as real as it gets in a simulated environment.

The one thing I didn't check yet is fuel flow, but... I mean I can literally use that chart in DCS and it'll be ON POINT. Like exactly. You don't even need DCS charts, just use that from the real thing. Even the mach numbers for a given drag index seem to fit.

Feel free to test everyone.

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2 hours ago, wilbur81 said:

Why are you only multiplying the ZLD CoE by wing area when fighters get lift (and drag) from the other parts of the aircraft (including stores and pylons that may or may not have been hanging for these various tests?  And what is the drag index loadout for 50 on the Viper? 

TOTAL DRAG (not limited to wing drag) = 1/2 * drag coefficient * air density * square of air speed * wing area. This is the DEFINITION. 

The drag coefficient is acquired in this way:

1) Testing the TOTAL drag.

2)  drag coefficient = 2 * TOTAL DRAG / (air density * square of air speed * wing area)

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4 hours ago, TobiasA said:

Even the mach numbers for a given drag index seem to fit.

Hey, Tobias. Yes, I did some re-testing of the mission shown, in my original reply to Carbon715, above with the drag values for the Viper. The new go at the FM definitely seems to fit the speculation that 3-bags; 6-Amraams, would in fact slow the Viper down slightly more than a slicker, no bags, only 2 pylons, and lighter Hornet... at least at the mid-teens altitude that I test both at. 👍

3 hours ago, karasawa said:

TOTAL DRAG (not limited to wing drag) = 1/2 * drag coefficient * air density * square of air speed * wing area. This is the DEFINITION. 

The drag coefficient is acquired in this way:

1) Testing the TOTAL drag.

2)  drag coefficient = 2 * TOTAL DRAG / (air density * square of air speed * wing area)

Karasawa... I'll have to tap out. I appreciate the formulas, and dynamic thrust conversation, etc... but I've reached my own max drag index. Here's my 'bug-out' from our conversation: 

  1. Lot 20 Hornet has more thrust than Viper, but not exceptionally more.
  2. Blk 50 Viper's GE engine is a MONSTER, much more powerful than Hornet's -402, but it only has one of them.
  3. Hornet is a draggier and heavier airframe than the Viper, which is why, all things being equal, the Viper has a higher T/W ratio.
  4. A Viper loaded up with drop tanks, Amraams, Pods, etc. will have a lower T/W and higher drag index (and therefore not be able to outright outpace) a slick, lighter configured Hornet. 
  5. All things being equal, the Viper will outpace the Hornet a good deal.

All these things above are currently exhibited in DCS with the Viper's sweet new (and Hornet's past) FM updates. So, I'm going to trust that ED and their team are privy to all the charts, formulas, and SME's and will do the work to keep us all rocking towards better and better 4th Gen jet simulation. 👍

And so, Carbon715🙂 Yes, as you've tested and seen, the new FM for the Viper has apparently gotten (just like the Hornet received a year or more ago) some more realistic drag simulation that slows it down in certain regimes a bit more than before, when its FM was less fully baked... 

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Guys, guys, guys... how important is it to you to win an internet debate on these forums? Is it worth risking possibly being investigated by a government agency? It seems like some of you think it is. I can tell you, it is not worth it, and we have had some go down that road already. This is no joke! Now, because some of you are not taking this seriously enough, we are going to have to look at increasing the punishment of a 1.16 violation, but for now, once again, I am warning you, do not post documents 1980 and newer than, unless you can prove that is publicly available and allowed to be distributed around the world, and you are 100% sure of that, don't share it. If you don't show proof that it can be shared, we will not research it for you, the post will be removed and you will be warned. I cannot stress enough how serious this is, and I cannot stress enough that this has happened to forum users already, and not the famous incident everyone knows about.

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