cauldron

Things that make you go... Hhhmmmm! :music_whistling:

Guys, please make proper tests and comments. 1. We all know the flight envelope is truncated structurally at M2.2 between 30k and 55k feet. Performance should NOT be the limiting factor for these conditions. Making a dive in clean config with probably very little fuel from 45k feet down to 42k feet is not helpful to the study. its also clear from the graph that it took a good while trying to get there too. 2. Optimum altitude for MACH, not speed, is ~40k feet. I just did a LEVEL flight test and it struggled to get to M2.2 at 40k feet, but it made it. It could not even break M2 over 50k or lower than 32K which it should with missiles and center tank on as well. This is not IMO enough to claim the "M2000 makes it to M2.2 easily" nor a basis to call other peoples data points wierd when they are not even proper data anyways, nor is yours. Next few days i'll be verifying the flight envelope, anyone is invited to participate - just please be rational, objective, and scientific about it. No wierd stuff ok? :smartass:

Hah! i had never heard of this movie. I just saw it, thanks for posting it. was fun to watch. :pilotfly:

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.

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

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?

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:

envelope 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.

Graph credits belong to J.M. Langeron AKA Topolo. Ok, so some layout of the testing: The graph below to be used as a baseline reference point so we can can a place to make comparisons - its not meant to be right or wrong, but its our best guess as to a good approximation of what should be: Roll Rate is degrees per second. The AoA should be held as constant aft stick pressure holding the AoA as best you can as you induce max roll commands. Give reference to your aircraft starting conditions, and FBW status and if its in NTTR or Caucus maps. Also to note, important on the roll rate tests is "dynamic pressure". BY definition Dynamic pressure represents the kinetic energy of the free airstream and is a factor relating to the capability for producing changes in static pressure on a surface. Q=1/2pV(2) Q=dynamic pressure, p=density, V= velocity, V(2)= Velocity squared. This dynamic pressure holds true for subsonic to hypersonic speeds. According to the graph: A Q=200 yields the lowest results and Q=800 yields the best results, and higher yields similar results. So i suggest we test the high end (best roll rate regime) by holding no lower than Q=800 and letting any errors in flying increase the Q as higher Q does not degrade much the roll rate. So how to we test this? How do we go in DCS and test roll rate at dynamic pressure gradients? Dynamic pressure is dependent of altitude and the square of velocity, - for example from sea level to 40k feet you need to double the TAS to have the same Dynamic pressure. Here is how we can do it, and come back here to share the results. Qbar or Q is measured usually in psf [pounds per square foot]. According to aerodynamics for naval aviators NAVWEPS 00-80T-80 we can get the following to work for us: to use Knots for speed we need a constant of .00339 which yields: Q=((density ratio)(velocity[kts] squared))/295 or... for a known value of Q which we have we can find the velocity we need to validate the gragh: V= "squareroot"of/((295xQ)/densityratio) density ratios: 10k feet .7385, 20k ft .5328, 30k ft .3741, 40k ft .2462 Qbar of 800 can be the following in a std atmosphere: sea level and 485knots 10,000ft and 565knots 20k ft and 665kts 30k ft and 794kts 40k ft and 979kts for the "slow roll" end of the tests i suggest the 200 Qbar line: sea level and 242kts 10k ft and 282kts 20k ft and 332kts 30k ft and 397kts 40k ft and 489kts So all we need to do is go fly and compare our results here: I'll set up another thread tomorrow for the MIL power and AB power level flight envelopes. cheers!

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...

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.

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.

Brisse, that's static thrust rating right? As the MIG21 & M2000 go faster and faster the drag on the MIG21 starts to degrade its performance significantly in comparison.

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 ;)

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.

piedroit - I've practiced your track and it helped me a lot... i'm getting a feel for it now. It helped a lot to know it was *not* predictive like the F-15's.. and i'm getting better at anticipating the bullet travel time... i can reliably hit now.!! Thank you.

Thanks again! Pied Droit I'm not as "force sensitive" as i used to be... but one can only get better with practice :thumbup:

My post did not have you in mind in any particular sense - but your reaction with "fine" and "dandy" as a way of mocking a call for respect - as far as i know - have nothing to do with "respect".

Cool thanks! :thumbup:

It would be good form, that if you debate the sources and or article of the OP you should also post your own sources backing up own own claims. Not one liners like some Jedi mind trick, "i know" so you are wrong thing... The OP went through some effort to present this in a formal fashion, do them the honor likewise if you wish to debate in kind. regards.

I see... still seems more pilot work load at a critical control input phase of flying, but for its worth, it can be made to work. Must get better using the force :joystick:

if that's true, sucks for the Rafale & Typhoon pilots in a dogfight. :joystick:

I have a question. Why does the gun piper (with the radar lock on the target) follow the gun snake? The gun snake is real time paths of bullets if fired, but the radar enabled piper should be predictive, much like that of the F-15's and Su-27/29's - but its not it follows the snake and becomes in essence a glorified range marker on the snake than a predictive mechanic. Is this a bug? or does the M2000 CQB radar gun mode non-predictive and is working as intended? cheers.

If the drawings are correct then, you can make some basic assumptions between them: The nose cone for the 530D is a better shape than the 530F, The fins are smaller. - in particular a better shaped nose + smaller less draggy fins = better kinematics alone due to less drag, let alone the other items you all speak of. I'll leave the rocket etc, to others who have better info.

Zeus, We clearly all want the best sim possible. The community has put a lot of passion and work into their involvement. That said impatience happens, we'll deal with it :cry: But it does give ED an opportunity to rally the sim community around DCS, it all depends on how they react. I do wish this opportunity to address the Matra missiles and missiles in general leads to a bigger DCS following. There is no greater community than the sim crowd, and DCS has such amazing potential. But the potential needs to be realized. P.S. i have been enjoying flying the M2000 greatly. Thanks razbam for making it. :pilotfly: