First order upwind on collocated grid arrangement
 

Hi all, Please help!!

I need to know what happens to the mass fluxes if first order upwind was used on collocated grid arrangement.

I have:
A_W=-max(mdot_w,0)
A_E=-max(mdot_e,0)
A_P=a_p + max(mdot_e,0)+max(-mdot_w,0)

I would appreciate an explanation. Please help as soon as possible I have posted a similar question previously and received no responce and I am unable to find references that explains this.

Thank you very much in advance.

A_W = -maximum(mdot_w, 0.0). If mdot_w < 0, then A_W = 0. If mdot_w > 0, then A_W = -mdot_w. A similar treatment holds for A_E and A_P. MAX(A,B) is simply a mathematical function that takes on the maximum value of the arguments in the argument list.