I am simulating 2-phase flow "water and air" in a 90 degree pipe. How to define the rotation axis origin and rotation axis direction of fluid under boundary condition?

Is your pipe rotate?? i dont think you shoud rotate your pipe

Is your pipe rotate??

my pipe do not rotate. That's why i wonder what is the "rotation axis origin and direction" of fluid under boundary condition.

sorry, make you wait

if you set motion type to stationary ,leave that to 0

if you set motion type to Moving reference frame, you need to specify your rotation axis. origin-------> set to 0 for all x,y,z direction----> set -1 (clockwise direction) or 1 for your rotation axis (for example y to -1)

god luck

Harry, My motion type is Stationary.So, you have solved my doubt.Thank you very much for your advice.

Max