Author Topic: Vapor trails would be cool (Read 3914 times)

Enduro · « **Reply #75 on:** October 01, 2005, 05:15:23 AM »

Quote

Originally posted by Clifra Jones
Yes they would be cool but I'd guess most would not want this as it is an unnecessary drain on frame rates.

MSFS2004 has vapor trails and the hit on frame rates is nill.

Brooke · « **Reply #76 on:** October 01, 2005, 01:40:33 PM »

Quote

Originally posted by JB42
715, the heat allows more water vapor (humidity). The more water vapor the more noticable the contrail. Back to meteorology school for you.

Actually, it's back to meteorology school for you, as 715 has it right. Here's a link for more explanation:

http://en.wikipedia.org/wiki/Contrail

JB42 · « **Reply #77 on:** October 02, 2005, 01:49:58 AM »

Brooke, nice of you to stop on the first page. Do a little link following and you get into humidities effect on contrail formation. Relative humidty is based on air temp. and its capacity to hold moisture. thanks.

The atmosphere contains water (which is why (Water falling in drops from vapor condensed in the atmosphere) rain occurs) and although most aero-engines are thought of as running on a fuel such as petrol/ (A volatile flammable mixture of hydrocarbons (hexane and heptane and octane etc.) derived from petroleum; used mainly as a fuel in internal-combustion engines) gasoline (piston engines) or paraffin/ (A flammable hydrocarbon oil used as fuel in lamps and heaters) kerosene (jet engines) they actually use a mixture of fuel and air, the air being taken from the atmosphere. This air contains moisture in the form of water-vapour, which passes through the engine and is heated in the cylinders/combustion-chambers and emerges as superheated (Water at boiling temperature diffused in the atmosphere) steam in the exhaust. For every gallon of fuel burnt, approximately one gallon of water (steam) is produced, depending on the fuel/air ratio. At high altitudes this steam emerges from the exhaust into a freezing environment, (as altitude increases, the atmospheric temperature drops) which lowers the temperature of the steam until each individual droplet freezes into tiny ice crystal

tactic · « **Reply #78 on:** October 02, 2005, 01:51:35 AM »

yah, what Kweassa said! fighters wing tips!!!!!

and a little from bombers ... what ever makes them on bombers! just a little

nothing else matters in this thread but vapor trails!!!!! nothing!

gimme a "V" , gimme a "A" , gimme a "P" , gimme a "O" , gimme a "R" Trrailllss! lol just gimme!

eilif · « **Reply #79 on:** October 02, 2005, 02:12:17 AM »

high aoa vapor trails are nice for keeping a good feel for what your plane is doing as a visual cue, and what your enemy plane is doing, you can tell easy that they are pulling a break turn ectra.

RobMo68 · « **Reply #80 on:** October 02, 2005, 03:22:57 AM »

Quote

Originally posted by tactic
yah, what Kweassa said! fighters wing tips!!!!! and a little from bombers ... what ever makes them on bombers! just a little nothing else matters in this thread but vapor trails!!!!! nothing! gimme a "V" , gimme a "A" , gimme a "P" , gimme a "O" , gimme a "R" Trrailllss! lol just gimme!

yeah, what he ^^^ said!

and yes, MSFS2004 does have "vapor trails" vissible, but those ARE dependant on your display settings and weather settings (lets face it, some vid cards, even the best ones, just won't cut it with all kinds of clutter).
Also, those "vapor trails" are mostly from aircraft at BIG ALT, flying a steady heading and speed, not in a plane yankin and bankin at 8k.

Edbert · « **Reply #81 on:** October 02, 2005, 08:50:10 AM »

IL2/FB/AEP/PF has both types of trails. All engines leave them at high alt, and with high G moves the wingtips will create readilly visible trails. No discernable FR hit on my rig with either.

tactic · « **Reply #82 on:** October 02, 2005, 02:00:19 PM »

yup they getm yanking and banking at 8 k, I've got some videos of wwII and vietnam prop planes ripping in on ground tragets and sure enough vapor trails comming off there wings.

Hell when I'm in my 71 340 duster and I floor the son- o- bioch and push that little Nitrous button, then I put my hand out the window, guess what?... you got it!!! vapor trails come off my hand.

lmao! ... No freaking f15 or any other plane got watermelon on me!! lol!!! Mopar ya know

Brooke · « **Reply #83 on:** October 02, 2005, 03:15:12 PM »

Quote

Originally posted by JB42
Brooke, nice of you to stop on the first page. Do a little link following and you get into humidities effect on contrail formation.

I gave you a reference to the whole thing, not just the first page.

You implied that 715 was wrong in his analysis when in fact he is correct. The engine contrails are because the engines are giving off water vapor (from the combustion process), which when ejected into cold atmosphere forms contrails. That is exactly what 715 said, it is exactly what the reference I gave said, it is exactly what physics says should happen, and it is not what you said in your message where you told 715 he didn't know what he was talking about.

You said, "715, the heat allows more water vapor (humidity). The more water vapor the more noticable the contrail. Back to meteorology school for you." Yes, higher temperature air will hold more moisture, but that is at most a point that is tangential and relatively unimportant compared to the main cause -- injection of water vapor from the combustion process -- which you completely miss in your expalantion.

If you had a nuclear powered aircraft, your exhaust would be plenty hot, but there would be no injection of water vapor and no engine contrails. If you just injected water vapor without raising the outlet temperature above ambient, you would make contrails. Thus, temperture of the exhaust is not the thing -- injection of the water vapor is the thing, which is what 715 said.

JB42 · « **Reply #84 on:** October 03, 2005, 12:05:08 AM »

No, 715 said heat had nothing to do with it, when in fact it has almost everyting to do with it. Fighter engine exhaust is broken into x amout of manifold outtakes. This causes the moisture in the exhust to come down in temp thus leaving a less defined contrail and more just adding moisture to the air. Bomber engines aren't so much. The exhuast is still super heated and with 2-4 engines in close proximity, produces a much more visable contrail.

Another factor is the reason the moisture needs to be super-heated. All exhaust has moisture in it. So why does super- heated exhaust cause a more noticable contrail when all moisture for the most part will freeze up there? Because in order for the moisture to become super-heated, the exhuast has to be super hot. This allows more super-heated moisture PPM and thus creating a more noticable contrail.

Brooke · « **Reply #85 on:** October 03, 2005, 03:51:56 PM »

Quote

Originally posted by JB42
No, 715 said heat had nothing to do with it, when in fact it has almost everyting to do with it.

715 is right -- it is due to moisture from the combustion process, not heat. Inject moisture, you get engine contrails, regardless of heat of the engine. Don't inject moisture, you don't get engine contrails, regardless of the heat of the engine. The more moisture injected, the more the engine contrail. The reason engine heat doesn't matter is that, shortly after it is ejected, the moisture is at ambient temperature regardless. The condensate that results doesn't care (or know) if it came from a hotter engine originally or a less-hot engine originally. The equations covering this contain only ambient conditions and amount of water vapor -- the heat of the vapor at some point in the past isn't in them.

B-17 and B-24's with their 4 engines give off 4 engine contrails. P-47's and P-51's with their 1 engine give off 1 engine contrail. That's the source of differing size of contrails (that and how much fuel/time is burned per engine), not engine heat.

Here is a picture of bomber contrails, 1 per engine:

Here is a picture of bombers and fighters with contrails, 1 per engine.

gatt · « **Reply #86 on:** October 04, 2005, 05:53:28 AM »

Sorry for posting off topic, however its hard to believe that there arent at least *some* of those so called "gameplay concessions". In AcesHigh, Targetware or X-plane.

I cant believe that in real life a Spitfire, (or whatever) could do a 180deg flat turn after a co-level HO merge and stay on the tail of a 350mph TAS flying 109 (or whatever) ... and dont talk to me about lag.
I cant believe it was so easy to land or take off with those heavy, super powered, torque monsters, instable (what else?) fighter planes.

Energy management concessions? I really dont know .... it is too easy, anyway.

That said, I enjoy playing AH since 1999. I tried TW and the beautiful Target Tobruk data pack (plenty of italian fighters and bombers never seen before in any sim), but I still prefer AH2.

RobMo68 · « **Reply #87 on:** October 04, 2005, 07:54:38 AM »

Quote

Originally posted by tactic
yup they getm yanking and banking at 8 k, I've got some videos of wwII and vietnam prop planes ripping in on ground tragets and sure enough vapor trails comming off there wings.

Hell when I'm in my 71 340 duster and I floor the son- o- bioch and push that little Nitrous button, then I put my hand out the window, guess what?... you got it!!! vapor trails come off my hand. lmao! ... No freaking f15 or any other plane got watermelon on me!! lol!!! Mopar ya know

FOKKER OFF!
Nah bro, I was talking about MSFS2004, not IRL ! IRL it all depends on ur Alt, speed, AOA, temp and relative humidity!
At least you got a respectable machine,:aok (DOES IT HAVE THE SIX PACK?) and not somthin Found On Road DEAD!

PS, How the sqaudies doin? I'll be back in the MA, soon (if RacerX, and the crew will still have me, and "D" hasn't run ya'll into dust)!

Did I give you my new e-mail addy? It's in my profile ,pass it RX & crew if ya would!

Lye-El · « **Reply #88 on:** October 04, 2005, 11:06:52 AM »

Quote

Originally posted by gatt

I cant believe it was so easy to land or take off with those heavy, super powered, torque monsters, instable (what else?) fighter planes.

I believe toward the end of the war some of the German and Japanese pilots had a little as 9 hours training to take off and land those heavy, super powered, torque monsters..

Fllying a plane isn't that hard. Fighting it is another story. After all it IS designed to take off and land.

Brooke · « **Reply #89 on:** January 24, 2006, 01:24:08 AM »

I was chasing a Typhoon at high speed in the Main Arena last Sunday. As I got close, he pulled lots of g's -- and I saw vapor trails off his wingtips. Unless I was seeing things, HTC has put in this feature request.

Has anyone else noticed or seen this yet?