[Roland R]

Hello,

I tried to validate the simulation of a standard orifice flow meter. The main goal is to investigate and check the discharge coefficient. Based on the theoretical calculation and measurement, the discharge coefficient should be about 0.6 in the investigated Re number region.
http://www.engineeringtoolbox.com/or...uri-d_590.html
Based on the result of my numerical analysis, this value is 0.77. I think, this difference is high, but I don’t understand its reason. I used unsteady analysis, SST turbulence model and very fine structured hexa mesh. The y plus value is correct. I used symmetry boundaries, so a quarter tube (90 degrees) was calculated instead of the full (360 deg) model. Maybe is it the problem? Or any other thing?

Regards
Roland