x[sin(time)] x z[cos(time)]

sin(time) in x multiplied by cos(time) in z will give a circular motion in 3D.
This technique can be very useful for making a tornado type of fx to get the circular motion.

sincos


vector $pos = particleShape1.position;
float $timeOffset = (time/3 + particleShape1.particleId);
float $radiusIncrement = linstep(0,12,particleShape1.age);
particleShape1.position = <<4*$radiusIncrement*sin($timeOffset),$pos.y+.1,4*$radiusIncrement*cos($timeOffset)>>;

sincos2