Space and astronautical engineering

Introduction to the course. How to prepare and pass the exam. Reasons to get high chamber pressure and system designs to achieve this goal Jet expansion systems: conventional and advanced nozzles Cooling systems in liquid rocket engines Propellant tanks: main design and sizing aspects Pressure-fed systems Basic characteristics of pump-fed systems and comparison with pressure-fed systems Turbomachines in liquid rocket engins: macroscopic balances, the Euler’s equation for turbomachinery, methods for the flow analysis ; velocity triangles; degree of reaction, efficiencies Pumps: nondimensional parameters and characteristic curves, introduction to cavitation problems Axial turbines: nondimensional parameters, classification, performance, impulse turbine single rotor, pressure compounded and velocity compounded Turbopump assembly: possible arrangements, constraints on the rotational speed Gas generators: open and closed cycle architectures The gas generator and expander bleed cycles: performance analysis based on power balances and secondary flow contribution to overall performance The staged combustion and expander cycle; performance analysis based on power balances, comparison among different possible arrangements. Introduction to combustion instabilities in liquid rocket engines.

Knowledge of the basic theory and the physical-mathematical tools necessary for the analysis and design of rocket propulsion systems, of the main performance parameters of rockets and of the main families of chemical rockets. In particular: - Knowledge and ability to apply the ideal rocket theory - Knowledge fundamental properties and methodology for the analysis of compressible flows - Knowledge and ability to apply the theory of compressible flows - Ability to analyze a gas dynamic problem and of its mathematical formalization - Knowledge and ability to apply the ideal nozzle theory - Knowledge and ability to apply the thermochemistry applied to chemical propulsion - Knowledge of the main combinations of propellants available for chemical propulsion - Knowledge of the main components that make up a liquid propellant rocket engine and ability to estimate its performance according to the propellant properties

Lecture notes made available by the teacher on the course website at https://elearning.uniroma1.it

Course attendance is recommended yet not compulsory.

Oral exam. The duration of the oral exam is about 45 minutes and is organized in three parts: 1) discussion of one of the team homework carried out during the course 2) discussion of one of the basic subjects deal with in the course (examples are: heat transfer, tank pressurization, pumps, turbines, nozzles, ...) 3) critical discussion of a LRE system. Criteria used for student competency assessment A) Outstanding: 29-30 (about 16% of successful exams). The student shows an excellent knowledge of the course subjects and is able to brilliantly apply the acquired knowledge. B) Very good: 27-28 (about 21% of successful exams). The student shows an excellent knowledge of the course subjects, however he is not brilliant in applying the acquired knowledge; the student shows a good knowledge of the course subjects, with some omissions that do not jeopardize the brilliant application of the acquired knowledge. C) Good: 25-26 (about 33% of successful exams). The student shows a good knowledge of the main course subjects and is able to apply the acquired knowledge. D) Satisfactory: 23-24 (about 20% of successful exams). The student knows most of the main course subjects and is able to apply the acquired knowledge to them. E) Sufficient: 18-23 (about 10% of successful exams). The student shows a partial knowledge of the course subjects and is only partially able to apply the acquired knowledge. He however shows to have reached the minimum required knowledge to pass the exam.

Ronald W. Humble, Gary N. Henry, Wiley J.Larson. “Space propulsion analysis and design” Space Technology Series, first edition revised, New York, The McGraw-Hill companies, 1995. Sutton G.P., ``Rocket Propulsion Elements'', An Introduction to the Engineering of Rockets, Sixth Edition, John Wiley and Sons, Inc., 1992. D.K. Huzel, D.H. Huang, “Design of Liquid Propellant Rocket Engine”, AIAA Series, Progress in Astronautics & Aeronautics, Vol.147. Stephen D. Heister, William E. Anderson, Timothée L. Pourpoint, R. Joseph Cassady, "Rocket Propulsion", Cambridge University Press, Cambridge, UK, 2019. https://doi.org/10.1017/9781108381376