CSP-based chemical kinetics mechanisms simplification strategy for non-premixed combustion: An application to hybrid rocket propulsion

Ciottoli, Pietro P.; Malpica Galassi, Riccardo; Lapenna, Pasquale E.; Leccese, G.; Bianchi, D.; Nasuti, F.; Creta, F.; Valorani, M.

CSP-based chemical kinetics mechanisms simplification strategy for non-premixed combustion: An application to hybrid rocket propulsion

Type

Article

Authors

Ciottoli, Pietro P.

Malpica Galassi, Riccardo

Lapenna, Pasquale E.
Leccese, G.
Bianchi, D.
Nasuti, F.
Creta, F.
Valorani, M.

Online Publication Date

2017-08-14

Print Publication Date

2017-12

Date

2017-08-14

Abstract

A set of simplified chemical kinetics mechanisms for hybrid rocket applications using gaseous oxygen (GOX) and hydroxyl-terminated polybutadiene (HTPB) is proposed. The starting point is a 561-species, 2538-reactions, detailed chemical kinetics mechanism for hydrocarbon combustion. This mechanism is used for predictions of the oxidation of butadiene, the primary HTPB pyrolysis product. A Computational Singular Perturbation (CSP) based simplification strategy for non-premixed combustion is proposed. The simplification algorithm is fed with the steady-solutions of classical flamelet equations, these being representative of the non-premixed nature of the combustion processes characterizing a hybrid rocket combustion chamber. The adopted flamelet steady-state solutions are obtained employing pure butadiene and gaseous oxygen as fuel and oxidizer boundary conditions, respectively, for a range of imposed values of strain rate and background pressure. Three simplified chemical mechanisms, each comprising less than 20 species, are obtained for three different pressure values, 3, 17, and 36 bar, selected in accordance with an experimental test campaign of lab-scale hybrid rocket static firings. Finally, a comprehensive strategy is shown to provide simplified mechanisms capable of reproducing the main flame features in the whole pressure range considered.

Citation

Ciottoli PP, Malpica Galassi R, Lapenna PE, Leccese G, Bianchi D, et al. (2017) CSP-based chemical kinetics mechanisms simplification strategy for non-premixed combustion: An application to hybrid rocket propulsion. Combustion and Flame 186: 83–93. Available: http://dx.doi.org/10.1016/j.combustflame.2017.07.035.

Acknowledgements

The authors acknowledge the support of Italian Ministry of University and Research (MIUR), as well as that provided by KAUST 1975–03 CCF Subaward Agreement.