Hi, dear cfd experts:

To compute flow in rotating reference frame, centrifugal force and coriolis force are added into the mementum equation.

For constant rotational speed, omega,

centrifugal force = omega X (omega X r) (where r is postion vector). coriolis force = -2m(omega X U)

What if omega varies with time? Is there any extra force term needed to be added into mementum eq?

Thanks!

phsieh2005

You will also have a term composed of the time derivative of omega crossed with the position vector. It has the same sign as all the other noninertial terms.