Numerical Modeling of Flow Through Orifice Meters. Topical Report July 1986-August 1987

摘要

Numerical modeling is performed for turbulent flow through orifice meters using Creare's computer program FLUENT. FLUENT solves the time averaged Navier-Stokes equations in 2D/3D Cartesian or cylindrical coordinates. Turbulence is simulated using a two equation k-epsilon or algebraic stress turbulence model. It is shown that an 80x60 grid distribution is sufficient to resolve the flow field around the orifice. The variations in discharge coefficient are studied as a result of variation in beta ratio, Reynolds number, upstream and downstream boundary conditions, pipe surface roughness and upstream swirl. The effects of beta ratio and Reynolds number on the discharge coefficient are shown to be similar to the experimental data. It is also shown that the surface roughness can increase the discharge coefficient by about 0.7% for the range of roughness heights encountered in practice. The numerical modeling approach would be most effective if it is combined with a systematic experimental program that can supply the necessary boundary conditions. It is recommended that numerical modeling be used for the study of other flow meters.