Mirage 2000 performances

[sedenion]

No doubt flying style is a part of the problem. There is a reason why most aircraft have higher wing aspect ratio. Weight/thrust is not top notch either. Do not expect sustained high G turns.

 

Wing aspect ratio does not made all... it seems there is a very hard bias about this "delta wing high drag"... Compare with a Su-27 for example, do you really beleive the agile M2k's small delta wing should cause this huge drag comparing to the Su-27's large and flat general shape ? Technically - and you don't need to make complex computing - it is obvious that the mass of air displaced by a Su-27 is at minimum the double than what a M2k displace, then keep in mind that the air density/viscosity is the same for both aircraft, you can easily understands that Su-27 generates in fact much more drag (compensated by two huge Saturn AL-31 engines) than the M2k despite its delta wing configuration... so there is no reason the M2k have this so high drag and bad performance compared to the Su-27, and clearly, just compare M2k and Su-27 in air show, the M2k is more agile, and fortunately.

Edited June 7, 2017 by sedenion

[OnlyforDCS]

Wing aspect ratio does not made all... it seems there is a very hard bias about this "delta wing high drag"... Compare with a Su-27 for example, do you really beleive the agile M2k's small delta wing should cause this huge drag comparing to the Su-27's large and flat general shape ? Technically - and you don't need to make complex computing - it is obvious that the mass of air displaced by a Su-27 is at minimum the double than what a M2k displace, then keep in mind that the air density/viscosity is the same for both aircraft, you can easily understands that Su-27 generates in fact much more drag (compensated by two huge Saturn AL-31 engines) than the M2k despite its delta wing configuration... so there is no reason the M2k have this so high drag and bad performance compared to the Su-27, and clearly, just compare M2k and Su-27 in air show, the M2k is more agile, and fortunately.

 

Disclaimer: There is a bug, as Cpt. Smiley already acknowledged.

 

However I have to address this last post of yours. Drag is just one part of the equation. Yes the Mirage has a much lower drag wing compared to the Su27, however the Su27 also has a much higher lift compared to the Mirage.

 

Just saying, you can't just look at drag when comparing fighter designs, especially when talking about maneuverability.

[lemoen]

Disclaimer: There is a bug, as Cpt. Smiley already acknowledged.

 

However I have to address this last post of yours. Drag is just one part of the equation. Yes the Mirage has a much lower drag wing compared to the Su27, however the Su27 also has a much higher lift compared to the Mirage.

 

Just saying, you can't just look at drag when comparing fighter designs, especially when talking about maneuverability.

 

Flanker also has much higher thrust to weight ratio.

[OnlyforDCS]

Flanker also has much higher thrust to weight ratio.

 

Exactly. Thrust to weight, weight with fuel or when empty, mass distribution, weight with stores, fuselage lift, stores drag, etc.

 

All of these will affect how an aircraft behaves in a dogfight, and that's not even going into the energy states depending on speed and altitude, and G pulled.

[Exorcet]

Wing aspect ratio does not made all... it seems there is a very hard bias about this "delta wing high drag"... Compare with a Su-27 for example, do you really beleive the agile M2k's small delta wing should cause this huge drag comparing to the Su-27's large and flat general shape ? Technically - and you don't need to make complex computing - it is obvious that the mass of air displaced by a Su-27 is at minimum the double than what a M2k displace, then keep in mind that the air density/viscosity is the same for both aircraft, you can easily understands that Su-27 generates in fact much more drag (compensated by two huge Saturn AL-31 engines) than the M2k despite its delta wing configuration... so there is no reason the M2k have this so high drag and bad performance compared to the Su-27, and clearly, just compare M2k and Su-27 in air show, the M2k is more agile, and fortunately.

 

Aspect Ratio makes a huge difference, especially when you're slow. The only reason why modern fighters don't have high aspect ratio wings is because supersonic performance is valued.

 

I've actually done some CFD work on delta vs swept wings and the deltas really can be draggy at low speed. They produce powerful vortices which are helpful for lift but very harmful for drag. The delta needs to fly at a higher AoA to generate competitive lift at lower speed, and in doing so, the drag goes up noticeably. In my own tests, the delta could produce around 50% more drag for the same lift. This doesn't mean the Mirage is 50% draggier than comparable non delta fighters of course, but it shows that the difference can be significant.

[Tripleinside]

Dassault is a delta specialist... you can talk all the theory you want, please refer the the videos posted in this thread, where you can see for yourself a real 2000 at VERY HIGH AOA, very slow speed, able to sustain lift without the need of burners, AND recover the energy very easily while maintaining a high Alpha and using the post combustion !

 

Why don't want an over performing plane, just an FM reflecting the reality... even if it costs to the drivers of the other modules, which I suspect is the problem here !

[sedenion]

I never said the delta wings are same as a swept wings... I only said: i think there is a hard bias about how the M2k's delta configuration should be dragy/unperformant:

 

I really don't want to hear the "it's a delta/high drag" lecture. Yes it's a delta but not like a Mirage III delta. With the Mirage III performing slow speed/high AOA flight the elevons would be deflected upwards at a pretty considerable angle, effectively dumping lift of the platform and greatly increasing trim drag. Mirage 2000 is a relaxed static stability delta. Performing slow speed/high AOA flight the elevons are close to neutral or even deflected slightly downwards, further increasing lift, as you can clearly see here

[mvsgas]

Dassault is a delta specialist... you can talk all the theory you want, please refer the the videos posted in this thread, where you can see for yourself a real 2000 at VERY HIGH AOA, very slow speed, able to sustain lift without the need of burners, AND recover the energy very easily while maintaining a high Alpha and using the post combustion !

 

Why don't want an over performing plane, just an FM reflecting the reality... even if it costs to the drivers of the other modules, which I suspect is the problem here !

 

The problem with that video is that it does not show any viable data. We do not the speed, weight, AOA etc.

 

This video show a lot better info, but we can't tell which aircraft is from:

 

Video tend to lack information, one way or another. I'm just going to wait to see the updates.

[sedenion]

The problem with that video is that it does not show any viable data. We do not the speed, weight, AOA etc.

 

Here some "clear data" here:

 

This video show a lot better info, but we can't tell which aircraft is from:

 

This is a Mirage 2000... All Mirage 2000 (except if we go back to early 80's) have the same delta wing with M53-P2 engine. This may be the training biplace (B) variant, which would not make so much difference.

Edited June 7, 2017 by sedenion

[OnlyforDCS]

hard bias

 

I see no evidence of that. Delta wings ARE draggier than regular swept back wings at high angles of attack. However as Cpt. Smiley acknowledged, the DCS M2000C drag is too high, even for a delta wing, and this will be addressed. It's probably not a simple matter to do so, otherwise we would have had a fix by now.

 

You can claim otherwise to your heart's content, but the only bias that will show is yours.

 

https://en.wikipedia.org/wiki/Delta_wing

[sedenion]

You can claim otherwise to your heart's content, but the only bias that will show is yours.

 

One question, and some will perfectly guess the answer: What would have happened in this topic if CptSimely did not have come back admitting there is a bug ?

 

I have nothing else to say.

[razo+r]

One question, and some will perfectly guess the answer: What would have happened in this topic if CptSimely did not have come back admitting there is a bug ?

 

I have nothing else to say.

 

He already stated it before his comeback and this thread...

 

some remembered, some not

[sedenion]

He already stated it before his comeback and this thread...

 

some remembered, some not

 

And then, what about who did'nt remember ?... You perfectly know what i mean... everybody perfectly know what i mean.

[cypc]

One question, and some will perfectly guess the answer: What would have happened in this topic if CptSimely did not have come back admitting there is a bug ?

 

One question, and some will perfectly guess the answer: What would have happened if you started this topic in the BUG SECTION ?

[mvsgas]

Just clarifying, we all know there is a problem right now... right? and we are just talking to talk.

 

Here some "clear data" here:

 

Like many videos before and many that will be posted; What is the speed, AOA, weight, etc?

 

Will see what the changes bring once they are ready.

 

I can't wait for the F/A-18 module, we already got so many "this doesn't fly right" threads about the F-15, SU-27, P-51, 109, A-10C etc. Just curious what will be the complain on the 18.

[sedenion]

Like many videos before and many that will be posted; What is the speed, AOA, weight, etc?

 

Lets assume it is only some non-scientifical aproximation:

 

The propeller aircraft appear to be a Socata TB9 or something like this... Cruise speed : ~140 kts.

The mirage 2000 have central fuel tank + 2 MAGIC, he did not traveled through the entire France to encounter the lost aircraft, so we can assume it is almost full of fuel.

 

The altitude is almost constant, so the mirage 2000 is at an AOA arround 18°:

 

The Mirage 2000 is perfectly manoeuvrable and stable, swinging its wings for visual contact.

[OnlyforDCS]

Im not sure what you are trying to prove now Sedenion? Yes the Mirage 2000, like other relaxed stability pure delta winged aircraft, is maneuverable at high angles of attack. I don't see anyone here disputing that. It just requires a lot of thrust to do it, since it is also very draggy at those angles of attack.

[Dehuman]

Dassault is a delta specialist... you can talk all the theory you want...

 

Le sigh.

 

Just like that you reduce the credibility of anything you say to nought.

[mvsgas]

The Mirage 2000 is perfectly manoeuvrable and stable, swinging its wings for visual contact.

 

I do not question the performance of the mirage or any other aircraft (real life or in DCS) I question our ability to gather enough clear and concise information to loose all biases and see it's performance objectively.

[myHelljumper]

I do not question the performance of the mirage or any other aircraft (real life or in DCS) I question our ability to gather enough clear and concise information to loose all biases and see it's performance objectively.

 

This

[sedenion]

Im not sure what you are trying to prove now Sedenion?

 

Nothing, i just answer the question...

 

No one is disputing that, it just requires a lot of thrust to do it,

 

What is "lot of thrust" ? 100% ? Full AB ? 80% ? Unfortunately, we are not in the cockpit to check the engine RPM...

[sedenion]

Yet another purely aproximative video with no data:

 

 

Here it performs a low pass slow speed, it seem not have so much trouble to pull up and gain energy at the end... anyway, not much more than any other comparable non-delta aircraft.

[OnlyforDCS]

Nothing, i just answer the question...

 

 

 

What is "lot of thrust" ? 100% ? Full AB ? 80% ? Unfortunately, we are not in the cockpit to check the engine RPM...

 

What question?

 

A lot of thrust comparable to other conventional winged aircraft, which feature higher lift designs.

[sedenion]

A lot of thrust comparable to other conventional winged aircraft, which feature higher lift designs.

 

Comparable to, or compared to ?

[Tripleinside]

Le sigh.

 

Just like that you reduce the credibility of anything you say to nought.

 

don't get personal kiwi, i didn't...

 

i'm not going to fight this, there is an issue, it's being acknowledged.

 

it's beyond me some of you keep talking about delta wing drag or data (which you lot don't have anyway) to justify the inability for a FIGHTER to maintain its altitude with 15 degrees alpha even with burner on, and that the only way to recover is to order a down stick to unload the wing, as if the plane was powered by a piston engine...

 

 

i'm out on this subject, and i'll wait for a module update.

Edited June 7, 2017 by Tripleinside