I have been having a problem with a smoke simulation that falls apart after about 60 frames, and I can't for the life of me figure out why. For the first part of the simulation the smoke looks as I would expect but then it falls apart. The smoke is being produced from a particle emitter set to produce 1500 particles for 15 frames. It is for a train smoke simulation, and the domain is parented to an empty that the train is also parented to and begins to move at the time the simulation starts.
There are wind force fields - turbulence and wind. But removing the turbulence made no difference. I've done everything I can think of - including using a single emitter which actually was worse. It looks like there is an animated force field - something I definitely didn't do deliberately and cannot find anywhere anyway.
I just can't understand why it breaks apart the way it does. Note the screen grabs...the first picture shows what the simulation looks like just a few frames after the one on the right.