• 22N Thruster
• green propellant
• LMP103S

New technologies are developed in the project RHEFORM to facilitate the replacement of hydrazine with liquid propellants based on ammonium dinitramide. The replacement of hydrazine with high performance green propellants will make space propulsion more sustainable and better suitable for the requirements of future space missions.
The main objective of the project is to design and analyse the 22N LMP103S green propellant thruster. The design of the thruster is done, based on the technical specifications obtained from project RHEFORM. The other objective is to use 3D printable material in construction of thrust chamber and nozzle, furthermore, is to study mechanical behaviour of the thrust chamber.
The thrust chamber geometric parameters are calculated from required technical specifications and working conditions. MATLAB program is written and used to calculate nozzle bell contour coordinates. Rest of the parameters are calculated using simplified isentropic mono-dimensional relations. The three-dimensional model is created using CATIA software. The model is then transferred to ANSYS to perform fluid and mechanical analysis. The computation fluid dynamic analysis is performed to obtain pressure and temperature distribution along the flow inside the thrust chamber. The data obtained from fluent (CFD tool) is used as an input in static structural analysis. Then static structural analysis is performed with imported internal pressure, imported temperature, external pressure, and acceleration boundary conditions. Further free free modal analysis and prestressed modal analysis is performed.
The results obtained are concluded as, the design is structural feasible because the resultant von mises stress is less than the yield stress. The maximum deformation is observed on nozzle bell contour, and they are well within allowable limits. First six modes frequencies obtained in free free modal analysis are zero. The prestressed modal analysis, Ariane 5 vibration spectrum is located at lower frequencies (100Hz), since the frequencies obtained in all the cases of this project are above 3000 Hz. we can conclude that structure will not get exited during launch due to induced vibrations.
In future development of this thrust chamber, it is necessary to conduct random vibration analysis and fatigue analysis. Fluid dynamic analysis is also required for improving thrust efficiency. Injector and catalyst bed development (current project it’s a trade-off) is required.