An analytical model for characterizing the thrust performance of a Low-Pressure Micro-Resistojet

There is a clear trend towards the developments of micro-propulsion system to enhance the capabilities of nano- and pico-satellites. A promising propulsion option to meet the strict requirements of these small satellites is the Low-Pressure Micro-Resistojet (LPM) which works under rarefied gas dynamic regime. To simplify the engineering design of this propulsion system an analytical model has been developed using the fundamental physical models. This analytical model is based on the Kinetic theory of gases and the Maxwell-Boltzmann distribution of molecular velocities to describe the macroscopic flow parameters such as mass flow rate, velocity and pressure, and then to estimate the thruster performance. The equations are well known, but they are applied in this case using a particular approach in order to describe the physics behind this micro-propulsion system. Comparisons between numerical simulations using the Direct Simulation Monte Carlo method and the results of the analytical model, as well as experimental results, have been carried out. The analytical model using an accurate estimation of the transmission coefficient compared to the numerical simulation presents a maximum difference of 3%.