I am creating a tornado for a personal project and was having trouble controlling a situation this complex in a standard fluid container. It came to my attention that I could create a tornado using particles and fields in Maya and then attach those particles to a fluid container and have them emit voxel data to drive the fluid simulation. This is my first test. I neglected to turn buoyancy off in the fluid container and that's why the dust keeps going up past the top of the funnel. I will fix that in the next test. This contains 1 large inner emitter for the central shaft and 4 smaller emitters around the outside to create contributing funnels. I've also grouped all the emitters and told them to spin on the Y axis.