Under Relaxation factor
 

Hi,
i am implementing an under-relaxation scheme in an incompressible code. The code firstly solves for an auxilliary velocity, which does not take into account pressure effects. Then, it adds the influence of pressure through the incompressibility condition and corrects the velocity field. I am applying the method used in Peric book, where he mentions that under-relaxation modifications are done in the final linear system Ax=b, where x is the unknown(velocity). Does this linear system involve pressure term also?
What i have done, is that i implemented under-relaxation in the linear system for the auxilliary velocity. Is it correct? and how can i apply this method to the corrected velocity?through pressure?
I have implemented in also in scalar equations, which i think is straightforward.