MARCO ROTONDI

PhD Graduate

PhD program:: XXXVI


supervisor: Prof. Daniele Bianchi
advisor: Prof. Daniele Bianchi

Thesis title: Modeling of Conjugate Heat Transfer Including Ablation and Pyrolysis for Propulsive Applications

A crucial component of space transportation systems is the propulsive nozzle assembly. Here, due to the high temperature and velocity of the exhaust gases, harsh conditions in terms of heat fluxes are faced, leading to the requirement of a proper Thermal Protection System (TPS). Regarding Solid Rocket Motors (SRM) and Hybrid Rocket Engines (HRE), a common solution employed by the aerospace industries worldwide is to use a carbon-based ablative passive TPS. Different types of ablative materials can be employed to this scope, ranging from non-pyrolyzing ablators (e.g., graphite, carbon-carbon (C/C)) to pyrolyzing ablators (e.g., carbon-phenolic (CPh)). Anyway, regardless to the particular carbon-based ablative material selected, the ablative TPS carbon-based surface recedes because of its chemical interaction with the oxidizing species present in rocket engine combustion products, increasing the nozzle throat area and resulting in a engine performance loss. Moreover, it is important to ensure a proper sizing of the ablative TPS, leading to lightweight (i.e., minimum thickness) structures and preventing at the same time an excessive heating of the metallic nozzle back-wall beneath. In this context, reliable numerical models are required to accurately predict the thermochemical and thermophysical behavior of ablative TPS in terms of both surface erosion and in-depth heating. In this context, the aim of the present thesis is to propose and study different modeling solutions, ranging from high-fidelity to low-order models, to predict nozzle heating, ablation, and pyrolysis as typically faced by ablative TPS in propulsive nozzle applications. In particular, the first part of the present thesis is devoted to the presentation and development of high-fidelity models for both steady-state and transient flow-material in-depth heating, ablation, and pyrolysis simulations. The second part is instead focused on the derivation of low-order models for nozzle throat erosion predictions, to be used in engine preliminary design and parametric analysis. Regarding the first part, dedicated to high-fidelity models, a numerical framework for the investigation of nozzle ablation and its thermophysical in-depth material response has been established. In particular, axisymmetric Computational Fluid Dynamics (CFD) simulations including finite-rate ablative boundary conditions and pyrolysis gas species injection in the boundary layer, as well as eventual multi-phase flow effects on thermochemical erosion (the latter, a factor which has never received enough attention in the open literature) have been coupled to simulations obtained with the recently developed Porous material Analysis Toolbox based on Open-FOAM (PATO), a transient material response code with specific applications to ablative materials. The present thesis represents the first application of PATO in the open literature to propulsive nozzle ablative analysis. A novel numerical procedure for the generation of finite-rate thermochemical ablation tables for propulsive applications is proposed and described, overcoming the limitation of the classic equilibrium approach employed in state-of-art ablative material response codes. The results obtained by coupling CFD and material response simulations using three different coupling strategy and employing the calculated finite-rate ablation tables are validated by comparison with firing tests data for both SRM and HRE applications. In particular, concerning SRM, two different sub-scale versions of the Space Shuttle solid propellant booster employing a carbon-phenolic nozzle have been analyzed. On the other hand, regarding HRE, the experimental data from a group of 2kN-thrust class CAMUI-type hybrid rocket firing tests performed at the Hokkaido University have been employed for validation. The capabilities of the CFD-material response coupled approach in predicting the erosion onset time and the in-depth heating/pyrolysis of nozzle ablative TPS are stressed by comparing the obtained results with state-of-art steady-state CFD simulations, as well as with the available experimental data. Moving to the second and final part of the thesis, devoted to low-order models for nozzle erosion prediction, two different class of models (i.e., closed-form regression laws and and a reduced-order physic-based model) have been proposed, developed, and finally implemented in the European Space Propulsion System Simulation (ESPSS) platform. Models implementation allowed to improve the overall predictive capabilities of the solid/hybrid thrust chamber components available in the ESPSS framework by including nozzle erosion effects on engine performances. Models have been validated by means of comparison with a large number of CFD simulations and experimental data available in the literature.

Research products

11573/1706191 - 2024 - Computationalanalysis and regression laws for nozzle erosion prediction in hybrid rockets
Rotondi, Marco; Migliorino, Mario Tindaro; Bianchi, Daniele; Kamps, Landon; Nagata, Harunori - 01a Articolo in rivista
paper: JOURNAL OF PROPULSION AND POWER (American Institute of Aeronautics & Astronautics:1801 Alexander Bell Drive, Suite 500:Reston, VA 20191:(800)639-2422, (703)264-7500, EMAIL: custserv@aiaa.org, INTERNET: http://www.aiaa.org/, Fax: (703)264-7657) pp. 439-459 - issn: 0748-4658 - wos: WOS:001160540900001 (2) - scopus: 2-s2.0-85193291763 (2)

11573/1706268 - 2023 - T(H)RUST: applied research activities on liquid rocket propulsion at Sapienza University of Rome
Nasuti, Francesco; Bianchi, Daniele; Migliorino, Mario Tindaro; Grossi, Marco; Fiore, Matteo; Rotondi, Marco; Zolla, Paolo Maria; Latini, Beatrice; Fabiani, Marco; Cocirla, Gianluca; Sereno, Alessio; Montanari, Alessandro; Barbato, Vincenzo - 04b Atto di convegno in volume
conference: IAC 2023 (Baku, Azerbaijan)
book: Proceedings of the International Astronautical Congress, IAC - ()

11573/1706224 - 2023 - Role of Multiphase Modeling on Nozzle Thermochemical Erosion in Solid Rocket Motors
Rotondi, Marco; Grossi, Marco; Migliorino, Mario Tindaro; Bianchi, Daniele - 04b Atto di convegno in volume
conference: AIAA Scitech 2023 Forum (National Harbor, MD, USA)
book: AIAA Scitech 2023 Forum - ()

11573/1706220 - 2023 - Experimental and Numerical Analysis of Transient Erosion in Hybrid Rockets
Rotondi, Marco; Migliorino, Mario Tindaro; Bianchi, Daniele; Kamps, Landon; Nagata, Harunori - 04b Atto di convegno in volume
conference: 34th International Symposium on Space Technology and Science (ISTS) (Fukuoka, Japan)
book: Proceedings of the International Symposium on Space Technology and Science (ISTS) - ()

11573/1620473 - 2022 - Numerical analysis of nozzle erosion in hybrid rockets and comparison with experiments
Bianchi, Daniele; Migliorino, Mario Tindaro; Rotondi, Marco; Kamps, Landon; Nagata, Harunori - 01a Articolo in rivista
paper: JOURNAL OF PROPULSION AND POWER (American Institute of Aeronautics & Astronautics:1801 Alexander Bell Drive, Suite 500:Reston, VA 20191:(800)639-2422, (703)264-7500, EMAIL: custserv@aiaa.org, INTERNET: http://www.aiaa.org/, Fax: (703)264-7657) pp. 389-409 - issn: 0748-4658 - wos: WOS:000730844300001 (9) - scopus: 2-s2.0-85129324952 (17)

11573/1660825 - 2022 - Review and implementation of engineering models of rocket film cooling and nozzle erosion
D’Alessandro, Simone; Concio, Pierluigi; Rotondi, Marco; Bianchi, Daniele; Nasuti, Francesco - 04b Atto di convegno in volume
conference: European conference for aeronautics and space sciences (Lille, Francia)
book: Proceedings of EUCASS-3AF 2022 - ()

11573/1644024 - 2022 - Student firing tests and launches with commercial and self-made solid rocket motors
Migliorino, M. T.; Aiello, M.; Berti, M.; Rotondi, M.; D'alessandro, S.; Bianchi, D.; Jahjah, M.; Pizzarelli, M. - 01a Articolo in rivista
paper: ACTA ASTRONAUTICA (Elmsford N.Y.: Pergamon Press) pp. 23-34 - issn: 0094-5765 - wos: WOS:000800589700004 (0) - scopus: 2-s2.0-85130134678 (2)

11573/1667612 - 2022 - Numerical analysis of carbon-based nozzle erosion including transient heating and shape change
Rotondi, M.; Migliorino, M. T.; Bianchi, D. - 04b Atto di convegno in volume
conference: AIAA AVIATION 2022 Forum (Chicago, IL, USA)
book: Aiaa aviation 2022 forum - (9781624106354)

11573/1667075 - 2022 - Numerical assessment of camphor ablation flight relevance in hypersonic wind-tunnel testing
Rotondi, M; Migliorino, Mt; Bianchi, D; Pagani, P; Turchi, A - 01a Articolo in rivista
paper: JOURNAL OF SPACECRAFT AND ROCKETS (American Institute of Aeronautics & Astronautics:1801 Alexander Bell Drive, Suite 500:Reston, VA 20191:(800)639-2422, (703)264-7500, EMAIL: custserv@aiaa.org, INTERNET: http://www.aiaa.org/, Fax: (703)264-7657) pp. 1574-1591 - issn: 0022-4650 - wos: WOS:000824277900001 (2) - scopus: 2-s2.0-85139493002 (5)

11573/1709521 - 2022 - Transient material response analysis of carbon-based thermal protection systems for rocket nozzle applications
Rotondi, Marco; Migliorino, Mario Tindaro; Bianchi, Daniele - 04b Atto di convegno in volume
conference: 2nd International Conference on Flight Vehicles, Aerothermodynamics and Re-entry Missions and Engineering (FAR) (Heilbronn, Germany)
book: 2nd International Conference on Flight Vehicles, Aerothermodynamics and Re-entry Missions and Engineering (FAR) - ()

11573/1620457 - 2021 - Numerical analysis and wind tunnel validation of low-temperature ablators undergoing shape change
Bianchi, D.; Migliorino, M. T.; Rotondi, M.; Turchi, A. - 01a Articolo in rivista
paper: INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER (Oxford: Elsevier Science Oxford: Pergamon Press) pp. - - issn: 0017-9310 - wos: WOS:000674500100007 (8) - scopus: 2-s2.0-85108708782 (16)

11573/1644206 - 2021 - Student firing tests and launches with commercial and self-made solid rocket motors
Migliorino, M. T.; Aiello, M.; Berti, M.; Rotondi, M.; D'alessandro, S.; Bianchi, D.; Jahjah, M.; Pizzarelli, M. - 04b Atto di convegno in volume
conference: IAF Space Propulsion Symposium 2021 at the 72nd International Astronautical Congress, IAC 2021 (Dubai, UAE)
book: Proceedings of the International Astronautical Congress, IAC - ()

11573/1620467 - 2021 - Numerical analysis of nozzle transient heating and erosion in hybrid rockets burning HDPE
Rotondi, Marco; Migliorino, Mario Tindaro; Bianchi, Daniele; Kamps, Landon T.; Nagata, Harunori - 04b Atto di convegno in volume
conference: AIAA Propulsion and energy forum 2021 (Virtual Event)
book: AIAA propulsion and energy forum 2021 - (978-1-7138-4339-9)

11573/1544203 - 2020 - Numerical analysis of nozzle heating and erosion in hybrid rockets and comparison with experiments
Bianchi, D.; Migliorino, M. T.; Rotondi, M.; Kamps, L.; Nagata, H. - 04b Atto di convegno in volume
conference: AIAA Propulsion and Energy 2020 Forum (Virtual, Online)
book: AIAA propulsion and energy 2020 forum - (978-1-62410-602-6)

11573/1544205 - 2020 - Numerical and experimental analysis of capsules ablation and shape change including heating transient effects
Rotondi, M.; Migliorino, M. T.; Bianchi, D.; Pagani, P.; Turchi, A. - 04b Atto di convegno in volume
conference: AIAA Propulsion and Energy 2020 Forum (Virtual, Online)
book: AIAA Propulsion and energy 2020 Forum - (978-1-62410-602-6)

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