This study investigates the flow characteristics of asymmetric multi-stage orifices using computational fluid dynamics (CFD). Three-dimensional models with two to four asymmetric orifices were developed in ANSYS Workbench, and a transient analysis was conducted with the SST turbulence model. Sweep mesh and inflation mesh techniques were applied to capture the flow behaviors near the orifices and within the boundary layer. The results showed that the outlet pressure decreased as the number of asymmetric stages increased. Pressure hunting analysis revealed that the two-stage model exhibited the most stable performance with minimal fluctuation, while the three- and four-stage models showed higher amplitude variations. Velocity distribution and turbulence characteristics confirmed that additional stages increased the maximum velocity and eddy viscosity, and complex streamlines were observed near the orifices. These findings provide insights into the design and optimization of multi-stage asymmetric orifices for stable fluid flow control.

This study examines the influence of the number of orifice stages on flow characteristics using Computational Fluid Dynamics (CFD). Transient simulations were conducted with one to four stages under identical boundary conditions, employing the SST turbulence model. The results show that outlet pressure and pressure hunting behaviors are strongly dependent on the stage number. Single- and two-stage models exhibited periodic pressure oscillations, whereas three- and four-stage models demonstrated irregular or stabilized patterns, with the four-stage configuration achieving the lowest pressure hunting. The maximum velocity increased with the number of stages, with peak values observed at the orifice sections. Similarly, eddy viscosity intensified as the number of stages increased, indicating enhanced turbulent mixing. These findings highlight that the number of orifice stages plays a critical role in determining pressure stability and flow behavior, providing useful insights for the optimal design of orifice-based flow control systems.