Rotating insertion stream

Does anyone know of a convenient way to create a rotating pour stream? I have an application where I'd like to insert particles into a tank (roughly a cylinder along z-axis) as a fairly high speed stream coming from a nozzle (more or less a point source) inside the tank, but the nozzle rotates about the z-axis creating a ring-like spray pattern.

I'm aware of the gimbal demo simulation posted at this board, and in a pinch, that might work, but I'm afraid it might be difficult to get the right kind of dynamics coming out of the tube.

Thanks,
Chris