Numerical analysis of influence factors on stability for dual-stage gas pressure reducing regulator

A numerical model of a dual-stage gas pressure reducing regulator, which is used in an aircraft pressurization system, was established on the basis of finite volume transient model of single-stage gas pressure reducing regulator. A modularization simulation model was also set up for performance study of dual-stage pressure regulator. The influences of different structural parameters on the stability of the two regulators which have tiny structural differences were illustrated by a series of numerical simulation, and their results were compared and analyzed. According to practical needs, the sample variance of II-stage valve spool velocity was chosen as the stability index, numerical analysis was then conducted on the influence factors including the II-stage valve spool mass, the II-stage low-pressure cavity volume, the II-stage feedback cavity volume, and the II-stage diaphragm stiffness. Results show that designers can decrease the II-stage valve spool mass or increase the II-stage diaphragm stiffness to improve the stability of the regulator. The study can help designers to meet the engineering requirements with minimum expenditure.