fitness88 Posted March 30, 2013 Posted March 30, 2013 To better understand con trails can someone please explain to me the following: Is there a specific altitude when they start and stop? Do weather conditions in FC3 alter question #1? Is this consistent for all planes in FC3? Do missiles follow the same rules as would apply to questions #1 and #2, as for question #3 apply this to missiles? Thank you.
159th_Falcon Posted March 30, 2013 Posted March 30, 2013 Lets take the simulator environment here as reference, not the real atmoshpere. 1, start at 8000 meters and stop at 12000 meters (3 ft is about 1 m) 2, no idea, i suggest you set some settings in the mission editor and try it out. (there is an icon bar on the left, near the top is one to change weather conditions) 3, Yes, for all planes in DCS World in fact. 4, Yes, the process that produces contrails are the same for all engines. (to to be confused whit smokeless rocket motors, these still produce contrails) [sIGPIC][/sIGPIC] The keeper of all mathematical knowledge and the oracle of flight modeling.:)
fitness88 Posted March 31, 2013 Author Posted March 31, 2013 159th_Falcon Thank you for the response.
ebabil Posted March 31, 2013 Posted March 31, 2013 i guess in real life, contrails may show up at different altitutes due to other weather conditions. but no idea in dcs world FC3 | UH-1 | Mi-8 | A-10C II | F/A-18 | Ka-50 III | F-14 | F-16 | AH-64 | Mi-24 | F-5 | F-15E| F-4| Tornado Persian Gulf | Nevada | Syria | NS-430 | Supercarrier // Wishlist: CH-53 | UH-60 Youtube MS FFB2 - TM Warthog - CH Pro Pedals - Trackir 5
towsim Posted March 31, 2013 Posted March 31, 2013 There are different conditions where COTRAs are produced from: First you need humidity as gas in the air. This comes from the exhaust gas as result of a chemical process if fuel is burned. The other source of humidity is the ambient air its self. In dependence of the ambient temperature the air can hold a certain amount of water gas. The gas condensates to droplets if the temperature falls below the dew point temperature. The third and most important item is the need of condensation kernels. To condensate from gas to water a technical surface is needed. This surfaces are given by dust particles , salt particles and in case of COTRA from exhaust particles. In absence of condensation particles it is possible to cool down the air far below the dew point temperature. As a result, you can have a clear air without any cloud, but the air is oversaturated with humidity. The humidity cannot condensate because there are no condensation kernels available. Now, if a jet engine produces these kernels and additional humidity, the ambient humidity in the air will condensate immediately and a vapor trail becomes visible. At lower altitude, relatively close to the earth surface there is always a certain amount of condensation particles available. So humidity may condensate immediately. A jet engine would not cause any additional condensation. This becomes inverted as higher the aircraft is flying. The best condition for COTRA is super cooled oversaturated air. In dependence of the season, the top of moist air is around 36000 feet. Above this altitude the humidity reduces dramatically. Pilots talk about 'flying above the weather ' because you will find no clouds there. As a consequence no COTRA can be produced. Even the additional moisture produced by the jet engine will be consumed by the ambient air. This is shown by the length of a COTRA of only a couple of meters. The altitudes where COTRAS are visible depend on ambient temperature, humidity , amount of condensation kernels and probably the top of moist air. [sIGPIC][/sIGPIC]
Pyroflash Posted March 31, 2013 Posted March 31, 2013 26 to 39 thousand feet is the contrail level in DCS. ATM, there is no way of affecting this,and this will hold true regardless of changing conditions. If you aim for the sky, you will never hit the ground.
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