Comparison of GCH4/GOX rocket combustion chambers

This thesis aims to compare two different subscale combustion chambers, operating with a pro- pellant combination of gaseous methane (GCH4) and gaseous oxygen (GOx). In the current study, results from an experimental investigation on a single-element and a multi-element shear coaxial injector, having a square and a rectangular cross section, are presented. The similarities and the differences between the two combustion chambers in terms of geometries and operating conditions are analysed in detail. Developing new combustors, comparisons between two dif- ferent combustion chambers, as geometric and thermodynamic characteristics, are often made in order to predict performances. In this work, detailed informations about pressure and tem- perature distribution along the chamber axis are reported for the two combustion chambers. In addition, it is considered the temperature pro le versus time for the two hardware. All re- sult are examined at different operating conditions, particularly, varying the chamber pressure and the mixture ratio. As a result, through this thesis the higher combustion efficiency of the multi-element respect to the single-element combustion chamber is demonstrated.