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.

Abstract
1. 서 론
2. 유동해석
    2.1 Geometry
    2.2 Mesh
    2.3 CFX-Pre
    2.4 CFX result
4. 결 론
References

• 곽효서(Assistant professor, Mechanical Engineering Major, Dong-Eui University) | Hyo-seo Kwak Corresponding author