Study: Algorithms for rocket engine thermochemistry

Abstract

This thesis compiles the process of upgrading two libraries (INIST and HGS) which provide to their users the thermodynamics properties and algorithms needed to analyse liquid rocket engine feed cycles. First, the Thermodynamic theory for real fluids, ideal fluids and mixtures is reviewed, as well as the algorithms and tools that the libraries implement. For ideal gases, the NASA 7 coefficient polynomials are used while for real fluids, data interpolated from NIST is applied. Then, five rocket engine feed cycles analyses are carried out using the libraries. Turbomachinery (pumps, turbines) as well as combustion chamber, nozzles, mixers and heat exchangers are studied with a thermodynamic analysis. The obtained results show good agrement with data obtained from the literature. Finally, some additional utilities of the potential of the library are given: (i) a chemical equilibrium algorithm based on the direct minimisation of Gibbs free energy that is used to obtain the combustion chamber mixture of dissociated species; (ii) a surrogate of RP1 for the simulation of RP1-LOX rocket cycles; (iii) a study on the effect of using ideal gas versus real fluid properties