Weta43 Posted February 17, 2007 Posted February 17, 2007 I know the amraam is supposed to have a clean burning fuel (smokeless - which I have no argument with & know has been discussed on this forum before) that makes it harder to see, but I was just watching a video on u-tube of Su-27's launching at drones & I noticed that the missiles had considerably more visible trails when they were launched at altitudes high enough to give the planes con trails & I wondered if this was the case in LO - it's not - R-27 series & R-73 both have the same trail at altitude as at sea level. Not such a big deal as they have a pretty chunky trail anyway :-) - but the amraam should leave one too - unless they have no hydrogen in their fuel at all (no organic chemicals & nothing inorganic with hydrogen) & nothing else that would condense at those temperatures and pressures they should leave a con trail when planes are leaving one (burn anything with Hydrogen - any organic compound - in it & you get water vapour) - but they don't. I had a quick look on the web - the astra BVRAAM intended as an indidgenous R-77 replacement is said to have a smokeless fuel (also see any hobby rocket site). It uses HTPB as a binder/fuel. HTPB is hydroxyl terminated polybutadene & is full of hydrogen -there should be con trails on the AMRAAM at altitude. The simplest thing to do would be to give all missile con trails while at the propper altitude & while their motor is running. 1 Cheers.
Weta43 Posted February 17, 2007 Author Posted February 17, 2007 Mods - could you delete the other version of this thread? Don't know how I got two... Thanks Cheers.
Pilotasso Posted February 17, 2007 Posted February 17, 2007 The AMRAAM is not completely smokeless. All videos I have show it leaves a faint grey smoke trail. .
Cosmonaut Posted February 17, 2007 Posted February 17, 2007 Fixed :) For a moment I thought you were talking about the 120 smokeless motor hehe:doh: I and many others have mentioned this before, hopefully a faint smoke trail can be added before BS is released. You just don't get the same satisfaction when firing a missile unless its smoking :smoke: . Cozmo. [sIGPIC][/sIGPIC] Minimum effort, maximum satisfaction. CDDS Tutorial Version 3. | Main Screen Mods.
Bimbac Posted February 17, 2007 Posted February 17, 2007 The AMRAAM is not completely smokeless. All videos I have show it leaves a faint grey smoke trail. Confirmed.
Alfa Posted February 17, 2007 Posted February 17, 2007 For a moment I thought you were talking about the 120 smokeless motor hehe:doh: Hehe....no I am afraid I am just a mere thread deleting mortal :D . JJ
Weta43 Posted February 17, 2007 Author Posted February 17, 2007 I think at sea level it should be pretty much smokeless compared to missiles using older propellant technologies, but at high altitude it should create an actual contrail - & be almost as visible as any other missile. As I mentioned earlier - if all the missiles were given contrails while at those altitudes and while their motor was running, the problem would be fixed. PS: thanks Alfa. Cheers.
pho3nix Posted February 17, 2007 Posted February 17, 2007 As far as my understanding of contrails, they are actualy condensation trails, such that the rapid cooling of predominatly water causes the contrail 'cloud'. Granted, there is not much water in a rocket motor but the surrounding enviroment would contribute to the contrail. Therefore any missile traveling in the correct pressure region would create some contrail independant of the fuel used. I may be wrong, possibly reagents in the fuel would self condense or catalyse condensation.
Pilotasso Posted February 18, 2007 Posted February 18, 2007 I also hope the new shaders will resolve the toilet paper missile trails. :) It would also be nice if ED gave the AMRAAM the such faint grey smoke. .
Prophet Posted February 18, 2007 Posted February 18, 2007 Most commonly the contrail is from exhaust, check this site and you will see 3 pics of varying engine jets and how the contrail comes from the engine. http://www.skystef.be/contrail.htm Now if you do a search on Wiki; http://en.wikipedia.org/wiki/Contrail, it also says it can form from wingtip pressure but not as common.
pho3nix Posted February 18, 2007 Posted February 18, 2007 Yes that is true from the exhaust, but that is for air breathing engines, (air contains water) therefore the rapidly cooling water will condense. This may not be the case for internal oxident engines i.e. rockets, as the only rapid cooling of water must come from the heating of the enviromental water first by the rocket, then the return to temperature equlibrium via the cold ambiant air.
Weta43 Posted February 18, 2007 Author Posted February 18, 2007 pho3nix - Yep - they're ice crystals & the water from the fuel effectively 'cloud seeds' the ice clouds that form from the exhaust vapour & pull more moisture from the air. - Pound for pound I suspect there's probably a similar amount of water formed burning rocket fuel as there is burning jet fuel - if you burn organic chemicals you get water, the initial seed crystals behind engines are not formed by atmosheric water taken in & spat out the other end, but by the water formed through the combustion of the fuel, the hydrogen of the hydrocarbons + the oxygen from the air = water vapour. Same for rockets - the hydrogen of the hydrocarbons in the fuel (hydroxyl terminated polybutadene ) + oxygen from the oxidiser makes water vapour (edit - I looked it up - rockets use Ammonium perchlorate as the oxidiser (NH4ClO4) - rocket fuel makes water vapour as it burns) However - as most of the water that forms the ice clouds (contrails) is atmospheric & condenses onto the crystals formed from the exhaust gasses - or any other particles that are present at that altitude (which is how cloud seeding works) - as you said earlier, even without water vapour, any microscopic particles should be enough to cause contrails to form. It would be a fairly simple fix to make - the logic for contrails is already there, just add them to all missiles that's motors are burning... Cheers.
Prophet Posted February 18, 2007 Posted February 18, 2007 Yes that is true from the exhaust, but that is for air breathing engines, (air contains water) therefore the rapidly cooling water will condense. This may not be the case for internal oxident engines i.e. rockets, as the only rapid cooling of water must come from the heating of the enviromental water first by the rocket, then the return to temperature equlibrium via the cold ambiant air. Negative, has nothing to do with temperature but content of the exhaust. If Hydrogen is coming out, then it will combine with the oxygen in the air and form water, once the water exceeds the saturation point you get contrail. I believe someone else before me explained this to a T. *Edit* Ah yes in the original post ;) As to the topic, it would appear the 120 should leave a contrail at the higher altitudes. I will say I have noticed the contrail off the control surfaces when its pulling G's, usually when I am pulling up and into it, and it smacks me :)
Pilotasso Posted February 18, 2007 Posted February 18, 2007 Unfortunatly theres not much you could do for altitude dependent AIM-120 trail efects in the game, but for example the SLAMRAAM wich is almost identical to AMRAAM in all respects is shown smoking (light trail but nevertheless there) from ground launch in the video. The missile continues smoking right untill burnout. I assume then thats not altitude-condensation induced factors here that makes the missile smoke. Me thinks simply fuel combustion products from complex chemicals. You dont have always CO2 and H2o You know. ;) .
Prophet Posted February 18, 2007 Posted February 18, 2007 Unfortunatly theres not much you could do for altitude dependent AIM-120 trail efects in the game, but for example the SLAMRAAM wich is almost identical to AMRAAM in all respects is shown smoking (light trail but nevertheless there) from ground launch in the video. The missile continues smoking right untill burnout. I assume then thats not altitude-condensation induced factors here that makes the missile smoke. Me thinks simply fuel combustion products from complex chemicals. You dont have always CO2 and H2o You know. ;) Considering HTPB is hydroxyl-terminated polybutadiene, I think the oxyl part pretty much says it. On top of that, the oxidizer it reacts with will have lots of oxygen. Usually Ammonium Perchlorate it seems, which is NH4ClO4 , and then Aluminum powder for fuel. I am sure our AMRAAM engineers got some secret formulation they use, but the fact that HTPB itself and the oxidizer will release large amount of oxygen, I would think it will contrail. This video shows a lot of AMRAAM launches, some have tremedous amounts of "smoke" (mostly F-22 launches, which I assume are at very high alt) and others dont. The ones that do, you will notice it takes a while for it to build up, I would assume this is condensation forming, and not actual smoke.
pho3nix Posted February 18, 2007 Posted February 18, 2007 I am not fammilar with the saturation point that you are talking about but may I assume that this would be a function of temperature and pressure, as all phase conditions are, that is why you have the triple point of water. As for the rocket fuel that makes sense, 2(H) + O2 = 2(H2O) which has a translucent flame (out of the visible spectrum), as opposed to the old kero rockets which spue forth all manner of crap :) =Prophet= could you please link the orignal thread as i would like to know what the other explantion is. Cheers mate.
nscode Posted February 18, 2007 Posted February 18, 2007 You can speculate here and there, but we know from the combat report of the pilot of one of two MiG-29s shot over Bosnia in '99. that AMRAMs do smoke, and in fact smoke so much they were mistaken for aircraft. Never forget that World War III was not Cold for most of us.
Pilotasso Posted February 18, 2007 Posted February 18, 2007 ^^^^yes, the smoke is faint grey, similar to what some aircraft engines make. A regular smoke trail would be unmistakable. .
Pilotasso Posted February 18, 2007 Posted February 18, 2007 Cali, au contraire mon frere. Missile perfomance is already considered to be swiched over to WAFM for BS, though no promises made (if they dont make it is because there was no time). The smoke would be an easy task, easier than making the smoke pods in FC, since nothing changes than AMRAAMsmoke=1 instead of 0 in the exe and then change its color. :) .
GGTharos Posted February 18, 2007 Posted February 18, 2007 It's not enough to change the color probably - the particle effect needs tobe changed also. [sIGPIC][/sIGPIC] Reminder: SAM = Speed Bump :D I used to play flight sims like you, but then I took a slammer to the knee - Yoda
Force_Feedback Posted February 18, 2007 Posted February 18, 2007 When will the mica and R-73 get thrust vectoring? I suspect the answer will include the words 'freeze' 'hell' and 'over' And tweak that cheesy flame on the aim-120, it looks very cartoonish now, guess the lack os smoke makes the thing look all cute. Creedence Clearwater Revival:worthy:
GGTharos Posted February 18, 2007 Posted February 18, 2007 I suspect when we get WAFM. [sIGPIC][/sIGPIC] Reminder: SAM = Speed Bump :D I used to play flight sims like you, but then I took a slammer to the knee - Yoda
D-Scythe Posted February 18, 2007 Posted February 18, 2007 When will the mica and R-73 get thrust vectoring? I suspect the answer will include the words 'freeze' 'hell' and 'over' What makes you think the Archer is not modelled with TVC right now? AFAIK, it's just not animated, but the R-73 rates (as in turn-rate/g's) the best out of all missiles in the game. Furthermore, you can't dive and beam it to make yourself instantly invisible, much like you can for all radar missiles.
Anytime Posted February 18, 2007 Posted February 18, 2007 maybe we need a duty cycle time hehe, switch it on/off on/off then a red light shows up on your dash, followed by an amraam in your mirror. Lets make sure the 120 is fixed before we start thinging about doing this. The link below is a test that I ran, you can check it out for yourself. All the US missiles have a serious problem. And this whole ECM burn through/ ECM blinking stuff needs to be fixed (ECM blinking is people turning it on/off a bunch of times) People who do that are noobs. Look here http://forum.lockon.ru/showthread.php?t=21345&page=3 "I just ran a test of off the rail speeds on the 120 and 77 the results are, 120 = 1770 off the rail 77 = 1924 off the rail both test were done at 26,000 feet and around 350-375mph so to go along with your post the 77 did retain speed better then the 120. The 120 dropped speed like it had a parachute behind it. <--- as Rugg said. So the 77 has a total speed over the 120 by 275-300mph and it doesn't lose speed as fast. "
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