How to simulate engines spraying a fluid?

Question

You know an aircraft engine? The gigantic fans on the sides of the aeroplane? Well, there will be seven of those in a circle facing to where the powder comes out and it will spray a liquid onto it.

How should I attempt this, please give examples!

Many thanks

Answer 1

Particles:

For the fluid being blown by a fan/turbine, you could try a particle system. For a really thin fluid/mist, simulating it as a bunch of spheres is probably overkill.

Instead you could try using textured planes (or Billboards):

1. Add a emitter plane and rotate it 90 so it is standing on its edge:

   

2. Add a Particle system to the emitter plane in Properties > Particles.

   Blender Internal:

   For BI you can use Billboard particles (these don't work in cycles):

   

   Cycles:

   For cycles you will need to use a slightly different technique to render billboard objects:

   1. Set the particles to use an object for rendering in Particles > Render > Object.

   2. Add another plane and add a Track To constraint to make it track to the camera (Select the plane and then the camera, then press CtrlT> Track To constraint):

      

   3. Set the To and Up settings of the constraint in (with the plane active) Properties > Constraints so that the plane faces the camera:

      

   4. With the emitter plane active, set the Dupli Object to the plane with the constraint and enable Rotation so that the particles will use the rotation defined by the constraint:

      

3. Lower the influence of the scene gravity in Particles > Field Weights > Gravity:

   

4. Add a Wind force field (ShiftA> Add > Force field > Wind) and rotate it 90 degrees so it is parallel to the emitter plane:

   

   You may want to tweak the strength in Properties > Physics.

5. Add a Vortex force field and rotate it 90 like the wind force:

   

Smoke:

If the fluid is really thin, you may want to try a Smoke Simulation.

Note that until Cycles has volumetrics (planned for 2.7) you will not be able to render the smoke in Cycles.

Answer 2

It seems like you want the array modifier. This modifier will let you create a single object (like a jet turbine) and then duplicate it in a controlled manner. Also, you'll want to use the object offset setting of the array modifier, rather than the xyz offset. That will allow you to make an array of (turbines?) around the target object in the center (usually just an empty).

Also, although the fluid sim seems like the best option, I'd recommend avoid it because it's probably more "expensive" than it's worth. There's probably a more efficient way to visualize the fluid. Maybe another particle sim? Or something that's not simulated?

Good luck!