A series of firing tests have been performed on a laboratory-scale hybrid rocket engine of 200 N class, fed with gaseous oxygen through a converging nozzle injector, to assess the mechanical feasib...

A numerical solver able to describe a rocket engine cooling channel fed with supercritical methane is validated against experimental data coming from a test article conceived and tested by the Italian Aerospace Research Center. The multidimensional conjugate heat transfer model numerically solves the Reynolds-averaged Navier–Stokes equations for the coolant flow and the Fourier’s law of conduction for the heat transfer within the wall. In this study, an experimental test case is reproduced in detail in order to evaluate the influence of partially unknown parameters, such as surface roughness and wall thermal conductivity, and of operative parameter uncertainty, such as the coolant mass flow rate and input heat transfer rate. The comparison made with respect to the wall temperature and coolant pressure drop of the whole set of experimental data provides complementary information that allows better understanding of experiments and infers possible deviations from the expected behavior.

Hall Effect Thrusters (HETs) are nowadays widely used for satellite applications because of their efficiency and robustness compared to other electric propulsion devices. Computational modelling of plasma in HETs is interesting for several reasons: it can be used to predict thrusters’ operative life; moreover, it provides a better understanding of the physical behaviour of this device and can be used to optimize the next generation of thrusters. In this work, the discharge within the accelerating channel and near-plume of HETs has been modelled by means of an axisymmetric hybrid approach: a set of fluid equations for electrons has been solved to get electron temperatures, plasma potential and the discharge current, whereas a Particle-In-Cell (PIC) sub-model has been developed to capture the behaviour of neutrals and ions. A two-region electron mobility model has been incorporated. It includes electron–neutral/ion collisions and uses empirical constants, that vary as a continuous function of axial coordinates, to take into account electron–wall collisions and Bohm diffusion/SEE effects. An SPT-100 thruster has been selected for the verification of the model because of the availability of reliable numerical and experimental data. The results of the presented simulations show that the code is able to describe plasma discharge reproducing, with consistency, the physics within the accelerating channel of HETs. A small discrepancy in the experimental magnitude of ions’ expansion, due probably to boundary condition effects, has been found.