Problems with rocket plume animation

Hello everyone!

I am trying to model a rocket plume using the fluid simulation feature in blender 2.49b

I am an intermediate user. I am trying to give it a flame-like shape, with a lattice deformation. The problem is that the emmitter I am using is a plane, and the flame isn’t smooth. The particles arrange themselves in planes.

What can I do to improve it? I attach the blender model

and a picture.

I also have tried without lattice, playing with the air drag and speed of the missile, but I can’t get the desired effect.

Thank you very much!