Hydrazine Catalytic Thrusters: Study on Monolithic and Spherical Catalysts in Decomposition Chamber

摘要

Propulsion is oneof the most importantprinciples in theperformance and efficieneyof a satellite.In this way, variouspropulsionsystemshave beenintroducedand applied.Thrusters based on chemical propulsion are one of the applicable systems in recent satellites.In this article, the hydrazine thruster has been introduced and reviewed briefly.The heterogeneous catalyst as the important part ofa hydrazine thruster has been studied and various structures and shapes of catalysts have been introduced.Then, two types of catalysts including spherical and monolithic catalysts have been synthesized and characterized by XRD and TEM analysis.Finally, the reactor performance of these catalysts has been tested.Analyzing the reactor results indicates that the monolithic catalyst has less pressure drop than spherical catalyst (about 50％ less).Also,the results show that in a same reactor length filled with different types of catalysts, there is difference in final compositions of products.Hydrogen percent is about 35％ in a monolithic reactor, whereas the mole fraction of hydrogen in a reactor with spherical catalysts is about 50％.This difference has been explained and studied in details according to the residence time of compositions in the reactor.