Effect of Spherical Silver Particles Size of the Catalyst Bed on Hydrogen Peroxide Monopropellant Thruster Performance

In this paper, an analytical approach combined with a two-dimensional computational fluid dynamics (CFD) model is pursued to simulate the fluid flow in a monopropellant thruster for satellite propulsion systems. The thruster utilizes hydrogen peroxide (H2O2) as a green propellant at a concentration of 87.5%, with a catalytic bed based on spherical silver particles. Through a parametric analysis of particle diameter, we aim to optimize the design of a monopropellant thruster capable of generating a thrust of 20N. For this purpose, a program in CFD code in the commercially available ANSYS Fluent software is used to solve the energy, momentum, mass transfer, and species transport equations governing the thruster system. The local thermal non-equilibrium (LTNE) approach is used to describe the heat transfer occurring through both the solid and fluid phases within the catalyst bed. The results demonstrate that particle size significantly affects the thermal behaviour, species mass fraction, and exit velocity. An optimum diameter of 0.65mm exhibits the optimal performance of the monopropellant thruster, ensuring efficient decomposition of H2O2 at 968K and providing the required level of thrust force with a specific impulse of about 120s.