CFD-Based Investigation of Flow Through an Orifice Plate Meter under Different Conditions

Orifice plate meters are widely used for flow rate measurement in pipelines but their accuracy can be significantly affected under turbulent flow conditions. This study investigates the performance of orifice plate meters under turbulent flow conditions using a two-dimensional Computational Fluid Dynamics (CFD) model. The influence of orifice beta ratio (the ratio of orifice diameter to pipe diameter), surface roughness, and fluid type (water, air, and oil) on the discharge coefficient (C_d) and pressure drop was analyzed through 45 simulations. Results show that increasing the beta ratio (0.42~0.58) increases the discharge coefficient (C_d) and reduces pressure drop for all fluids, improving flow efficiency. Surface roughness had negligible impact on (C_d) at Reynolds number = 50,000, while velocity profiles remained consistent across fluids, with maximum velocity decreasing at higher beta ratios. Vortex formation at the outlet diminished with increasing beta ratios and disappeared entirely at the highest beta ratio value. Velocity and pressure contours show the effects of these parameters on (C_d), illustrating the performance of orifice plate meters in turbulent flow scenarios.