Numerical simulation on dynamic stability of pressure reducing regulator in integral bipropellant propulsion system

A finite volume transient model of a high pressure unloading pressure reducing regulator (PRR) with diaphragm, which is used in a integral bipropellant propulsion gas system, was established. Based on this, a modularization numerical model of a characteristic research system for PRR was established. Then aiming at the instabilities observed during testing operation, the influences of several structural and control parameter on the stability of PRR were clarified by a series of numerical simulation. Those measures which can improve the dynamic stability include: reducing the mass of valve spool, increasing the volume of high-pressure chamber or low-pressure chamber, increasing the damping coefficient of springy elements material, reducing the size of feedback orifice, increasing the stiffness of diaphragm. The comparison with the experimental and simulation results in earlier literature confirms the effectiveness and feasibility of some measures.