Jet flame

[Synoptic]

Hi! (^_^)/ I'm trying to make a fighter jet engine flame, but I still can't get a good looking result. (>_<) Could someone suggest me the most appropriate settings of PhoenixFD plz?! It should consist of flame, smoke trail and the refracting heat haze.

THANKS!

[Ivaylo Katev]

as starting point you can use the rocket example scene included in the package, of course you have to remove the floor. if the produced jet is not strong enough, you have to increase the source discharge. this will produce significant slowing down of the simulation, but c'est la vie.
for heat haze switch on the geometry mode and heat haze options (requires VRay) and adjust the multiplier. by defoult the temperature is used.

[Synoptic]

as starting point you can use the rocket example scene included in the package, of course you have to remove the floor. if the produced jet is not strong enough, you have to increase the source discharge. this will produce significant slowing down of the simulation, but c'est la vie.
for heat haze switch on the geometry mode and heat haze options (requires VRay) and adjust the multiplier. by defoult the temperature is used.

So I need to get 2 types of flame with smoke trail and without it. But I'm newbie and the PhoenixFD is a blackbox for me so far. Could you plz give me a more detail description of the parameters that I should adjust from the default PhoenixSource and the default PhoenixSimulator in order not to overload the process of simulation. So the first one is the source "discharge". I can't figure out where is the "geometry mode and heat haze options". I have the V-ray Adv 1.50.SP5 (^_^)

THANKS!

[Ivaylo Katev]

want not to discourage you, but the smoke trail is a hard task due to the huge grid size you need.
for the source the discharge is the only important parameter here. for the simulator watch the Steps Per Frame (SPF) indicator, too high values are a symptomp for "overloading" of the core, but the extremly high speed of the jet requires significant overloading, perhaps SPF should be more than 20. for comparison the usual camp fire produces SPF about 2-6. to increase the performance you can try to use bigger advection step, this reduces the SPF. you can also try with fixed SPF (equal upper and lower SPF limits), this can be useful too. the heathase control is in the "rendering" rollout.
and read the manual, especially the introduction.

[Synoptic]

There are such many interdependent parameters in the introduction, so I hardly can guess the result without practice. There is no way "how to make jetflame with PhoenixFD". So I'm trying to light 2 objects with one simulator. I've almost got the flame I want, but it's too short! When I increase the "discharge" option the one flame becomes more volume than another! After increasing the "energy" parameter the flame looks hotter than another one.
Is it possible to light two objects with one simulator?

THANKS!

[Ivaylo Katev]

what you meant with "light" two objects with one simulator? increasing the discharge produces more volume because you are using fuel, in the real jet engine the burning is inside and the jet is just hot gases without any fuel and burning. try to use temperature only, in this case the discharge should control the length of the jet.

btw, as i said the smoke trail is a hard task, because the huge size. but i think it can be faked with particle flow, phoenix has PF operator that can drag particles. when the particles are out of the grid they will continue their movement with the last velocity they have. as shader you can try to use the environment fog with gizmo the particle system and some smoke like texture for the transparency.

[Synoptic]

http://img513.imageshack.us/img513/6243/568.mp4

[Synoptic]

Here is the video, I couldn't find "edit" button on this forum, so

I can't do a thing (>_<) One flame looks LARGER! And both flames stick to the top of the simulator!

Here is my scene 3dsMAX 2011x64. Could you plz look at it?

THANKS!

[Ivaylo Katev]

the jets are stick to the upper wall because the gravity - the real jet is much faster (hundred meters per second) and have no time to rise. of course simulating such high speed is too expensive, so you need to switch off the gravity. however even with gravity switched off i would recommend to expand a bit the grid - the walls are too near to the work area.
can't say why the first jet looks larger without detailed investigation.

[Ivaylo Katev]

your scene with little tweaks:

the discharge is increased to 1000, gravity is off, cooling 0.3, the cooling is important because it gives the proper shape of the jet. the heat haze have to be decreased i think, is too strong and this makes the box visible.

edit: new rendering with heat haze=2

[Synoptic]

Didn't you tweak the "vorticity" param? My flame looks much more turbulent than your.
There are the settings:
discharge 1000, gravity is off, cooling 0.3, SPF upper limit 40, SPF lover limit 20, vorticity 3, conservation 2

http://img189.imageshack.us/i/ojj.mp4

THANKS!

[Ivaylo Katev]

your'e right, the vorticity is zero
btw, the resolution is also higher

[Synoptic]

The "conservation" affects the resolution eventually?

You've really helped me! \(^_^)/ THANKS!

[Synoptic]

And the last! I've made the simulation from 50 to 70 frame. Is there the way to loop the animation of my 20 simulated frames?

[Ivaylo Katev]

interesting question. the only way i think is to use the "anim. index" option, when is checked the index is directly given by the value in the edit box.