Mathematical modeling of a pneumatic pressure regulator for aerospace application

Abstract

High precision Pressure Regulators with wide operating pressure ranges are required for steady performance of Liquid Rocket Propulsion Systems. A Non-linear, dynamic mathematical model, for a dome loaded pressure regulator which meets this requirement essential to understand its behavior has been developed. The thermodynamic property variations of the working medium are modeled using mass and energy conservation equations. A characteristic regulator equation consisting of operating forces and Coulomb friction and pneumatic damping is used to model the dynamics of the regulator. The simulation is carried out by varying characteristic geometrical parameters such as the size of the damping orifice, poppet step length and regulator downstream volume. The effect of varying friction force on the start transient of the regulator is studied. Experiments by varying the same parameters as the simulation are carried out to validate the model. The simulation results show good concurrence with the experiments. This model serves as a tool for optimising the performance of the regulator at a particular flow rate and regulated pressure by arriving at appropriate geometrical parameters.

Keywords:

• Pressure regulator
• dome loaded
• mathematical modeling
• outlet pressure
• model validation
• experimental tests
• optimisation studies
• damping