gravity option and specified operating density
 

hi

I am studying an 3D 90º elbow using water like a fluid in order to compute head losses. I have made a simulation by using gravity option for axis Y (-9.81 m/s2) and specified operating density 0. Is it right for this example. Should I use that options or should I use the density of water for specified operating density?.

I have used velocity inlet and outflow as boundary conditions

Thanks