AIRCRAFT ENGINES

Course objectives

Knowledge and understanding Knowledge of the first principles of thermo-fluid dynamics of the engine, of the almost-one-dimensional compressible flows, of the thermodynamic cycles of the main gas turbine engines, of the flow in axial turbo-machines, in the dynamic intakes and aeronautical propulsive nozzles, of the correlation techniques of the losses in axial turbomachinery, of the equilibrium and non-equilibrium thermochemistry of combustion in the combustor, of the main phenomenologies, theories, and mathematical / numerical models that characterize the combustion processes in mixtures of chemically reacting gases, of the integration of the engine in the aircraft system , quantifying the environmental impact due to emissions of greenhouse gases, pollutants and noise from aircraft engines, and the factors on which we act to try to limit it, both at the component level and at the system level (architectures propulsion and innovative thermodynamic cycles). Applying knowledge and understanding Ability to perform a rough sizing of the components of an aeronautical engine, and of the in and out of project performance of the same components, using calculation tools produced by the students themselves during the group work. The training objectives are pursued using classroom exercises and reviews of work in progress. The verification of the skills acquired takes place at the same time as that of the knowledge during the reviews and in the course. Autonomy of judgment (making judgments) Skills are acquired through lectures, classroom exercises and for carrying out group work. Verification of knowledge takes place through individual tests and through written group reports which at the same time ensure and promote the acquisition of the ability to communicate effectively in written and / or oral form. Communication skills Ability to work in a group, to present the results of group work with presentations and short technical reports. Ability to learn (learning skills) Knowledge characterizing the systems engineer of aeronautical propulsion understood as a preliminary design of the engine and verification of its performance in project and off-project conditions.

Channel 1
MAURO VALORANI Lecturers' profile
RICCARDO MALPICA GALASSI Lecturers' profile

Program - Frequency - Exams

Course program
The course illustrates the numerical techniques for the performance prediction of a typical aeronautical jet engine, highlighting the sensitivity to the main thermal-fluid dynamics parameters of performance, in terms of power or thrust and consumption, and highlighting the behavior of the device in both design and off-design conditions. 1. Principles of chemical non-equilibrium thermodynamics and compressible flows. Review of the fundamental principles of thermodynamics, equations of state, chemical equilibrium. Conservation laws (mass, momentum, and energy), and fluid motion equations in isothermal and non-isothermal systems; microscopic and macroscopic balances. Differential and integral form of the equations for quasi-1D compressible flows, with heat induction, friction and area variation. Fanno and Rayleigh problems. 2. Engine Cycle Analysis Overview of the main engine performance parameters. Introduction to the engine design process. Constraint and mission analysis of the aircraft for the calculation of the required thrust according to customer needs. Engine cycle analysis through parametric analysis. Multi-objective optimization. Pareto Frontier. 3. Sizing of Engine Components: intake and propulsive nozzle Sizing of subsonic and supersonic intakes. Sizing of convergent and convergent-divergent propulsive nozzles. 4. Sizing of Engine Components: Turbomachines Introduction to Turbomachinery, frame of references, velocity triangles, momentum conservation, Euler equation for turbomachinery, efficiencies, design criteria in the meridian plane, radial balance, design criteria in the meridian plane. 5. Mean path analysis of compressors and axial turbines 6. Blade rows Introduction to blade cascades, blade flow angles, blade cascades performance, design criteria. 7. Sizing of a turbomachinery stage How to size an axial compressor stage How to size an axial turbine stage 8. Loss correlations Loss correlations in turbomachines, loss mechanisms, and loss patterns 9. Off-design performance of compressors and axial turbines Off-design performance of compressors and turbines: off-design velocity triangles, performances maps of compressors and axial turbines 10. Off-design of gas turbine engines Off-design performance of the entire engine: matching conditions among components, off-design performance
Prerequisites
Basic knowledge of fluid mechanics, fluid dynamics, thermodynamics and supersonic aerodynamics, fundamentals of aerospace propulsion.
Books
Pasquale Sforza, Theory of Aerospace Propulsion, Butterworth-Heinemann (2011) S.L. Dixon, C.A. Hall, Fluid Mechanics and Thermodynamics of Turbomachinery, 6th ed., Elsevier (2010) Saravanamuttoo, Rogers, Cohen, Gas Turbine Theory, Pearson Education Ltd., 5th ed., 2001 Meinhard Schobeiri, Turbomachinery Flow Physics and Dynamic Performance, Springer (2005) Saeed Farokhi, Aircraft Propulsion, Wiley John + Sons (2008) Hill-Peterson, Mechanics and Thermodynamics of Propulsion, 2nd Ed. , Addison-Wesley, 1992 A.F. El-Sayed, Aircraft Propulsion and Gas Turbine Engines, CRC Press, 2008 N. Cumpsty, Jet Propulsion, Cambridge U. Press, 1997 A.H. Shapiro, Compressible Fluid Flow, Vol.1, Wiley, 1953
Frequency
In presence.
Exam mode
The assessment includes a written test, an oral test, and the evaluation of a group paper produced during the course. The written test consists of open-ended questions. The written test lasts 3 hours; you are not allowed to use any material during the test. The projects will be valued by adding 0/30 to 3/30 to the mark obtained after the written and oral tests. The delivery of the paper is a pre-requisite to take the written test.
Lesson mode
The course will be delivered through frontal lessons in presence and/or in telematic mode. The course materials and all communication between teacher and student will be managed through the Google Classroom platform which can be accessed using any internet browser. All interested students are therefore invited to register on the Google Classroom page of the course of interest using their INFOSTUD credentials. Students who enroll in the course will receive an email notification of the lesson calendar which will be provided in telematic mode until otherwise specified.
  • Lesson code1021988
  • Academic year2024/2025
  • CourseAeronautical engineering
  • CurriculumModellistica e analisi per la progettazione aeronautica (percorso valido anche per il conseguimento del doppio titolo con Georgia institute of technology and Georgia tech Lorraine o per il doppio titolo Italo-portoghese )
  • Year1st year
  • Semester2nd semester
  • SSDING-IND/07
  • CFU9
  • Subject areaIngegneria aerospaziale ed astronautica