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DB605
05-22-2011, 10:43 AM
I tried to search about this subject but did not find anything. So does anyone know why there is not any kind of vapor trails in COD? Or is it another feature that has been removed from game? They would add quite lot of immersion to game in my opinion.

Ploughman
05-22-2011, 10:57 AM
Yes, t'other day I took a Spit Mk IIa up to 28,000ft + and there was a vapour trail.

DB605
05-22-2011, 11:33 AM
Yes, t'other day I took a Spit Mk IIa up to 28,000ft + and there was a vapour trail.

Really? Need to test it again myself, i have only been about 7,500 metres and did'nt saw any trails then. Also there should have trails from wings when manouvering hard i.e. during dogfights (like there was in orig.IL-2), anyone seen them in COD?

Strike
05-22-2011, 12:06 PM
Really? Need to test it again myself, i have only been about 7,500 metres and did'nt saw any trails then. Also there should have trails from wings when manouvering hard i.e. during dogfights (like there was in orig.IL-2), anyone seen them in COD?

The aircraft contrails caused by the aircraft engines are a result of the combustion of fuel. The main bi-products of fuel combustion are CO2 and Water. Contrails appear when water is released into the atmosphere at normally an altitude of ca 8,000m or above and at temperatures below -40C. When all the water molecules enter the atmosphere they quickly saturate the air with water, causing the water to condensate and form tiny droplets of water. When combined with temperatures below -40 the water becomes supercooled and will turn into ice particles instantly if "triggered" by a disturbance. This disturbance is provided by the exhaust particles from the engines and therefore the particles freeze instantly, causing these nice frozen clouds in the sky.

Mind you wingtip vortices are more common during some atmospheric conditions than others, mainly dependant on air humidity. I do, however, think they forgot to include the effect in the initial release. It would add for some realistic dogfighting visuals. But even during very rainy days, one can see the vortices on takeoff/landing from say, the tip of the deployed flap, because there is a huge difference in air pressure between the flap and the rest of the wing.

Vortices are generated at wingtips because of a higher pressure under the wing, than above the wing. At the very tip of the wing, the higher pressure manages to "escape" around the wingtip to the upper surface, thus inducing a spin. Seen from the rear; the left wingtip will have a clockwise spin, and the right wingtip a counter-clockwise spin. The speed of which the air travels in this vortex has a resulting pressure and temperature drop. If this temperature drops below the local dew-point, the water will condensate and turn into visible droplets cotained within the vortex. In some weather conditions, if you're flying at enough speed, you'll see the vortices all the time, whilst in "normal" conditions, you'll see it during high AoA manouvers. This is because during these high AoA manouvers the difference in pressure between lower and upper surface of the wing is so great that the speed induced in the vortex lowers the pressure and temperature sufficiently to provide condensation in the local atmosphere.

Just thought I'd share that ;p

Ali Fish
05-22-2011, 12:12 PM
possibly why we dont see basic vapour trails is due to the weather system they are creating. and maybe the inclusion of that might see vapours being physical and visible ?

also i presume on july 15th 1942 it was summer time and less chance of vapours at low altitude due to low humidity levels.?

MadTommy
05-22-2011, 12:18 PM
http://img718.imageshack.us/img718/1246/shot20110519181559large.jpg

:grin:

DB605
05-22-2011, 12:22 PM
The aircraft contrails caused by the aircraft engines are a result of the combution of fuel. The main bi-products of fuel combustion are CO2 and Water. Contrails appear when water is released into the atmosphere at normally an altitude of ca 8,000m or above and at temperatures below -40C. When all the water molecules enter the atmosphere they quickly saturate the air with water, causing the water to condensate and form tiny droplets of water. When combined with temperatures below -40 the water becomes supercooled and will turn into ice particles instantly if "triggered" by a disturbance. This disturbance is provided by the exhaust particles from the engines and therefore the particles freeze instantly, causing these nice frozen clouds in the sky.

Mind you wingtip vortices are more common during some atmospheric conditions than others, mainly dependant on air humidity. I do, however, think they forgot to include the effect in the initial release. It would add for some realistic dogfighting visuals. But even during very rainy days, one can see the vortices on takeoff/landing from say, the tip of the deployed flap, because there is a huge difference in air pressure between the flap and the rest of the wing.

Vortices are generated at wingtips because of a higher pressure under the wing, than above the wing. At the very tip of the wing, the higher pressure manages to "escape" around the wingtip to the upper surface, thus inducing a spin. Seen from the rear; the left wingtip will have a clockwise spin, and the right wingtip a counter-clockwise spin. The speed of which the air travels in this vortex has a resulting pressure and temperature drop. If this temperature drops below the local dew-point, the water will condensate and turn into visible droplets cotained within the vortex. In some weather conditions, if you're flying at enough speed, you'll see the vortices all the time, whilst in "normal" conditions, you'll see it during high AoA manouvers. This is because during these high AoA manouvers the difference in pressure between lower and upper surface of the wing is so great that the speed induced in the vortex lowers the pressure and temperature sufficiently to provide condensation in the local atmosphere.

Just thought I'd share that ;p

Thank you for great explanation. My english is not good enough to write something like that, even i was aware most of the things :) I just recalled
contrails form after 7,000 meters, i stand corrected.

Vengeanze
05-22-2011, 03:30 PM
Vortices would be nice!

Blackdog_kt
05-22-2011, 05:31 PM
The aircraft contrails caused by the aircraft engines are a result of the combution of fuel. The main bi-products of fuel combustion are CO2 and Water. Contrails appear when water is released into the atmosphere at normally an altitude of ca 8,000m or above and at temperatures below -40C. When all the water molecules enter the atmosphere they quickly saturate the air with water, causing the water to condensate and form tiny droplets of water. When combined with temperatures below -40 the water becomes supercooled and will turn into ice particles instantly if "triggered" by a disturbance. This disturbance is provided by the exhaust particles from the engines and therefore the particles freeze instantly, causing these nice frozen clouds in the sky.

Mind you wingtip vortices are more common during some atmospheric conditions than others, mainly dependant on air humidity. I do, however, think they forgot to include the effect in the initial release. It would add for some realistic dogfighting visuals. But even during very rainy days, one can see the vortices on takeoff/landing from say, the tip of the deployed flap, because there is a huge difference in air pressure between the flap and the rest of the wing.

Vortices are generated at wingtips because of a higher pressure under the wing, than above the wing. At the very tip of the wing, the higher pressure manages to "escape" around the wingtip to the upper surface, thus inducing a spin. Seen from the rear; the left wingtip will have a clockwise spin, and the right wingtip a counter-clockwise spin. The speed of which the air travels in this vortex has a resulting pressure and temperature drop. If this temperature drops below the local dew-point, the water will condensate and turn into visible droplets cotained within the vortex. In some weather conditions, if you're flying at enough speed, you'll see the vortices all the time, whilst in "normal" conditions, you'll see it during high AoA manouvers. This is because during these high AoA manouvers the difference in pressure between lower and upper surface of the wing is so great that the speed induced in the vortex lowers the pressure and temperature sufficiently to provide condensation in the local atmosphere.

Just thought I'd share that ;p

Excellent explanation and probably the reason why a lot don't see them yet: they are not hard-coded at 7km of altitude like in IL2:1946, but dependent on weather conditions.

SG1_Lud
05-22-2011, 06:05 PM
The aircraft contrails caused by the aircraft engines are a result of the combution of fuel. The main bi-products of fuel combustion are CO2 and Water. Contrails appear when water is released into the atmosphere at normally an altitude of ca 8,000m or above and at temperatures below -40C. When all the water molecules enter the atmosphere they quickly saturate the air with water, causing the water to condensate and form tiny droplets of water. When combined with temperatures below -40 the water becomes supercooled and will turn into ice particles instantly if "triggered" by a disturbance. This disturbance is provided by the exhaust particles from the engines and therefore the particles freeze instantly, causing these nice frozen clouds in the sky.

Mind you wingtip vortices are more common during some atmospheric conditions than others, mainly dependant on air humidity. I do, however, think they forgot to include the effect in the initial release. It would add for some realistic dogfighting visuals. But even during very rainy days, one can see the vortices on takeoff/landing from say, the tip of the deployed flap, because there is a huge difference in air pressure between the flap and the rest of the wing.

Vortices are generated at wingtips because of a higher pressure under the wing, than above the wing. At the very tip of the wing, the higher pressure manages to "escape" around the wingtip to the upper surface, thus inducing a spin. Seen from the rear; the left wingtip will have a clockwise spin, and the right wingtip a counter-clockwise spin. The speed of which the air travels in this vortex has a resulting pressure and temperature drop. If this temperature drops below the local dew-point, the water will condensate and turn into visible droplets cotained within the vortex. In some weather conditions, if you're flying at enough speed, you'll see the vortices all the time, whilst in "normal" conditions, you'll see it during high AoA manouvers. This is because during these high AoA manouvers the difference in pressure between lower and upper surface of the wing is so great that the speed induced in the vortex lowers the pressure and temperature sufficiently to provide condensation in the local atmosphere.

Just thought I'd share that ;p

Indeed. You broke the scale with this post.
If we someday have the bible of Cod, i hope this is included

Strike
05-22-2011, 06:14 PM
Thank you for great explanation. I just recalled
contrails form after 7,000 meters, i stand corrected.

Hey, you're welcome for the explanation, but you are in no means at all wrong by saying 7,000 meters. That is just circa what it was in IL-2 1946 because the atmosphere was always the same. You'd get contrails in IL-2 because of the height you were flying at, not because of the surrounding air. So you could very well get contrails at 7000 meters, if it's cold enough :)


For the interested, here's showing that not only wingtips create vortices :)

Flap during typical humid day:

http://www.youtube.com/watch?v=TXDPCINTFKA

And this is why you need carburettor heaters :P

http://www.youtube.com/watch?v=TFYzHfjTGtk

That stuff would ice up really fast if it wasn't heated

Typical propellers also create vortices :)

http://www.youtube.com/watch?v=_g1SInGmRv0

unreasonable
05-23-2011, 02:25 AM
Nice posts, thank you.