Mig-21bis is now faster then Mirage-2000C In 2.0

[cauldron]

Brisse,

 

For my part yes, i checked it several times. full MIL power. You made no supersonic tests for the new patch, just subsonic. There is no transonic drag >M1.0 I have no real data points except Topolos work, which i am using as a baseline, since RAZBAM has used it also as a source.

 

I'll do some independent tests so we can compare.

Edited January 15, 2016 by cauldron

[cauldron]

F-15 glide vs M2000 it seems beyond a reasonable doubt that clean config the M2000 would have a MUCH better Polar curve at ANY speed than the F-15. Sub-sonic drag seems to be in question as well. Seems the transonic is on the money but sub sonic and super-sonic got borked on the last patch.

[0xDEADBEEF]

Ok, i'm going to validate Brisse's tests. So far the "transonic" drag seems to be supersonic drag as well. I'll post a graph soon. Remember Transonic is usually from ~M.85 ish up to M1.0 ONLY. the lower side depends on wing and fuselage design (ie area rule etc.) of when transonic drag effects start occurring.

 

But preliminary tests show that at 32000ft M2000 from M1.4 when reduced to MIL power falls back to M.9 even in the following condition: 50% fuel CLEAN - no tanks bombs or missiles.

 

 

Brisse, check your graph again, its half done only, and the supersonic side has some definite "issues". RAZBAM, i think your transonic drag fix carried over to the supersonic side ;)

 

searching for transsonic drag quickly brought up this interesting paragraph:

"In aeronautics, transonic refers to the condition of flight in which a range of velocities of airflow exist surrounding and flowing past an air vehicle or an airfoil that are concurrently below, at, and above the speed of sound in the range of Mach 0.8 to 1.0, i.e. 600–768 mph (965–1236 km/h) at sea level. This condition depends not only on the travel speed of the craft, but also on the temperature of the airflow in the vehicle's local environment. It is formally defined as the range of speeds between the critical Mach number, when some parts of the airflow over an air vehicle or airfoil are supersonic, and a higher speed, typically near Mach 1.2, when the vast majority of the airflow is supersonic. Between these speeds some of the airflow is supersonic, but a significant fraction is not." - source Wikipedia

 

I finally understood the fact that Transsonic Drag occurs because parts of the airframe are supersonic, while other parts are not. This makes perfect sense! I didn't get to test the new mirage yet unfortunately.

[cauldron]

searching for transsonic drag quickly brought up this interesting paragraph:

"In aeronautics, transonic refers to the condition of flight in which a range of velocities of airflow exist surrounding and flowing past an air vehicle or an airfoil that are concurrently below, at, and above the speed of sound in the range of Mach 0.8 to 1.0, i.e. 600–768 mph (965–1236 km/h) at sea level. This condition depends not only on the travel speed of the craft, but also on the temperature of the airflow in the vehicle's local environment. It is formally defined as the range of speeds between the critical Mach number, when some parts of the airflow over an air vehicle or airfoil are supersonic, and a higher speed, typically near Mach 1.2, when the vast majority of the airflow is supersonic. Between these speeds some of the airflow is supersonic, but a significant fraction is not." - source Wikipedia

 

I finally understood the fact that Transsonic Drag occurs because parts of the airframe are supersonic, while other parts are not. This makes perfect sense! I didn't get to test the new mirage yet unfortunately.

 

Actually its airflow that creates supersonic shock zones, NOT parts of the airframe going supersonic -(small but important point). Typically over lifting areas of the plane, usually the wings - they create lift by accelerating air and thus decreasing pressure that "accelerated air can reach M1.0 but it depends on the wing or surface of course as to when it starts to happen and how severe it is. This for example is the cause of the "high speed" wing stall as apposed to the standard AoA wing stall. So its not that exact that it starts at M.8

 

Also at supersonic speeds you can still has subsonic airflows behind shock cones. Thus the reason the engines can still operate with subsonic inflow of air, yet the plane is still supersonic. Something the M2000 has the ability to correct due to variable inlet cones in the engine intakes, as apposed to the F-16 which is fixed - making the F-16 have a speed limit due to compressor fail over M1.2 ish...

[Rlaxoxo]

Mig also has an emergency afterburner, maybe he had it turned on. IIRC it provides 95kN :D

 

I was flying the Mig-21 and I did not have emer afb

[Hook47]

Sounds like either RAZBAM got it right, or MIG21has it wrong, FC3 also seem to be "too" fast. So, the hard question to answer is, balance ie. a dcs standard or realism of one module vs non-realism "other" modules. Or, maybe the correction to M2000 was slightly over-done? Hard to say.

 

The other option could be that RAZBAM still has it wrong, I suspect it was "nerfed" a bit too much as the MiG FM seems quite close to the published data.

[TomCatMucDe]

I did some dogfights with the new update. The Mirage is much slower and handles less well. It seems like we were cheating with the first on steroid version against those migs.

 

she is much less powerful but more realistic I would say. Before, in the middle of a dogfight, you could skyrocket and they would never catch you.

Edited January 16, 2016 by TomCatMucDe

[Toertchen]

97 kN at full emergency afterburner

 

Source:

Mikoyan-Gurevich MiG-21, page 39, By Alexander Mladenov,Adam Tooby

 



Let's do that calculation again :)

 

T/W = 97000/(8725*9.81)= 1.13

 

Don't take that source... let's stay ingame.

 

What we have:

MiG21bis (44 kN dry, 71 kN wet, 99 kN emergency afb)

Empty weight: 6255 kg

Clean 100% Fuel: 8535 kg

E

-

C

44,0 kN - 0,70 - 0,53

71,0 kN - 1,15 - 0,85

99,0 kN - 1,61 - 1,18

 

Mirage 2000C (64 kN dry, 95,1 kN wet)

Empty weight: 7500 kg

Clean 100% Fuel: 10665 kg

E

-

C

64,0 kN - 0,87 - 0,61

95,1 kN - 1,29 - 0,91

 

 

 

Source:

 

Thrust:

1. MiG21Bis - Flight Manual from Leatherneck ( page 14 and 28 )
   
2. M2000C - Flight Manual from RAZBAM ( page 9 )
   

Weight:

 

• both: ingame DCS
  

[Rlaxoxo]

I did some dogfights with the new update. The Mirage is much slower and handles less well. It seems like we were cheating with the first on steroid version against those migs.

 

she is much less powerful but more realistic I would say. Before, in the middle of a dogfight, you could skyrocket and they would never catch you.

 

That's not the issue we were talking about that issue has been fixed and we don't have problems with that

[Hook47]

That's not the issue we were talking about that issue has been fixed and we don't have problems with that

 

After testing a bit I think this ties into the newer drag model, engine, or both. Even though the mig should probably be able to put accelerate the M2000 with EAB, it should not be able to without it, and the M2000 is supposed to be a bit faster, so I imagine Razbam needs to tweak th drag back a bit

[cauldron]

envelope

There is to much drag In mirage atm I can feel it

 

When you ran out of gas and you try to glide you super slow down to 300 kph

 

In an F-15 you can glide pretty efficiently around 600 kph or lower but with the mirage now I fly like a brick

 

Here's the pictures

 

#2 Mirage - High altitude max speed (IAS)

 

#3 Mirage - High altitude max speed (TAS)

 

Ok, according to the Level flight max AB the fastest speed would be the lowest altitude of the structural limit, as in clean config between 30k and 55k feet is the structural limit. thus the max speed should be attained just above 30k feet which is M2.2.

 

M2.2 at 30k feet is about 1296 Knots TAS or 2400Kph TAS as M1.0 at 30k ft 589kts/1091kphTAS

 

Clearly something has gone wrong. i suspect a typo in the math. its just to gross an error.

 

Also we should be wary about testing to structural limits, especially if the plane can't even reach the limits, as is now the case. I would suggest also testing to max speeds where its not limited by structure - ie. full A2A load plus center drop tank should make almost M1.8 at 40k feet. Also we need to look at the Polar Curve [inverted L/D max curve] for the subsonic glide profile which was mentioned earlier.

 

It seems the transonic drag 'fix' got applied across the board into the subsonic regime and supersonic regime. More testing may show where to look. I started a thread on roll rate testing, and will set up a schedule/system for testing level flight - turn rates - fuel burn -climb rates each day coming up. maybe together with proper testing procedures we can help refine the model to what it should be before final release.

Edited January 16, 2016 by cauldron
envelope testing suggestions

[RoflSeal]

Just edited my previous post, but fits here so I'll repost for visibility.

 

 

 

You also have to remember that the MiG has ~5min of EAB time if I remember correctly, then it all changes.

 

MiG-21 EAB is 3 minutes-30sec break- 3min-30 sec break etc

[Teeter]

Just popping in quick on my phone guys, but at first glance, I'm going to recommend the comparison to the MiG-21bis stops. There's a lot that LN got very, very right...but it's not realistic for it to reach 2.3 Ma at any altitude.

 

Please, lets keep the discussion comparisons between the M-2000C simulation vs. Reality, and not the M-2000C vs. The MiG-21.

[Rlaxoxo]

Ok, according to the Level flight max AB the fastest speed would be the lowest altitude of the structural limit, as in clean config between 30k and 55k feet is the structural limit. thus the max speed should be attained just above 30k feet which is M2.2.

 

M2.2 at 30k feet is about 1296 Knots TAS or 2400Kph TAS as M1.0 at 30k ft 589kts/1091kphTAS

 

Clearly something has gone wrong. i suspect a typo in the math. its just to gross an error.

 

With the mirage in this patch there is no possible way to go pass the Mach 2.07

 

No matter how hard I try

 

I know it won't mean much but just gonna post what's stated on wiki

 

General characteristics

 

Crew: 1

Length: 14.36 m (47 ft 1 in)

Wingspan: 9.13 m (29 ft)

Height: 5.20 m (17 ft)

Wing area: 41 m² (441.3 ft²)

Empty weight: 7,500 kg (16,350 lb)

Loaded weight: 13,800 kg (30,420 lb)

Max. takeoff weight: 17,000 kg (37,500 lb)

Powerplant: 1 × SNECMA M53-P2 afterburning turbofan

Dry thrust: 64.3 kN (14,500 lbf)

Thrust with afterburner: 95.1 kN (21,400 lbf)

Performance

 

Maximum speed: Mach 2.2 (2,530+ km/h, 1,500+ mph) at high altitude

Range: 1,550 km (837 nmi, 963 mi) with drop tanks

Ferry range: 3,335 km (1,800 nmi, 2,073 mi) with auxiliary fuel

Service ceiling: 17,060 m (59,000 ft)

Rate of climb: 285 m/s (56,000 ft/min)

Wing loading: 337 kg/m² (69 lb/ft²)

Thrust/weight: 0.7 at loaded weight

 

But overall Raznam really did a great job this patch

 

GJ Razbam team!!!

 

Just look over the drag again if you're reading this

Edited January 16, 2016 by Rlaxoxo

[cauldron]

wiki is not a great resource, its a start, but a good resting place to get information:

 

Topolos work is some of the better works i've seen to date, and since its referenced as a viable reference from the devs, i'll post the relevant chart for this thread i belive:

[Rlaxoxo]

wiki is not a great resource, its a start, but a good resting place to get information:

 

Topolos work is some of the better works i've seen to date, and since its referenced as a viable reference from the devs, i'll post the relevant chart for this thread i belive:

 

Awesome stuff thanks for that

 

So If I'm reading this correctly it's saying that with clean config the max speed is around 2.2 Mach?

[cauldron]

structural limit

 

Razbam i got a question?

 

How is the structural limit being addressed? Does the FBW start reducing engine power at M2.2 or is there/should there be an alarm for max speed as is the case for the DCS mig29? or is there an invisible drag applied when you reach M2.2.

 

I ask because prior patch the plane would just run up to the "wall" so to say and it would just stay there, engine would stay running the same, everything seemed the same but it just would not go any faster. Technically something needs to stop the plane at the structural limit. usually the flight envelope for some 'other' planes IRL they give a 15% margin before actual breakup.

 

But there is no flutter, no vibration, no computer warnings, and the engine does not reduce power. So how does it manage the structural limit ingame?

 

in similar lines... Is there any data for a V/N diagram for the Mirage?

Edited January 16, 2016 by cauldron
typos

[Corsair]

Max speed allowed, for safety and operational reasons. The actual max speed is a little past M 2,2, but if it could reach it, that'd already be a good start..

[cauldron]

Awesome stuff thanks for that

 

So If I'm reading this correctly it's saying that with clean config the max speed is around 2.2 Mach?

 

Yes, but only in between 31k feet and 54k feet or so, approx. higher or lower its slower. :smilewink:

[Rlaxoxo]

Yes, but only in between 31k feet and 54k feet or so, approx. higher or lower its slower. :smilewink:

 

Currently around 35k - 50k feet I can only manage to barely reach the speed of mach 2.01 and at low altitude around 3,000 feet I can reach the speeds of mach 1.08

Edited January 16, 2016 by Rlaxoxo

[cauldron]

Currently around 35k - 50k feet I can only manage to barely reach the speed of mach 2.01 and at low speeds around 3,000 feet I can reach the speeds of mach 1.08

 

Yup its broke, now comes the hard part. how can we help RAZBAM see the state of the current envelope, to help them make the relevant corrections.

[Rlaxoxo]

Yup its broke, now comes the hard part. how can we help RAZBAM see the state of the current envelope, to help them make the relevant corrections.

 

Hate this part

[Hummingbird]

wiki is not a great resource, its a start, but a good resting place to get information:

 

Topolos work is some of the better works i've seen to date, and since its referenced as a viable reference from the devs, i'll post the relevant chart for this thread i belive:

 

This is the performance I would expect as well.

 

Atm though reachinh Mach 1.2 at SL clean is not possible.

[Manuel_108]

This is the performance I would expect as well.

 

Atm though reachinh Mach 1.2 at SL clean is not possible.

 

So it's 0.8 off?

[Rlaxoxo]

So it's 0.8 off?

 

No reaching low altitude Mach 1.2 Is impossible

 

As well as reaching High altitude 2.2 mach is impossible atm