B019235 - AEROENAUTICAL GAS TURBINE AERODYNAMICS

italian

Aeroengines architecture for civil aviation
Boundary layer transition in turbomachinery
Noise emissions in aeroengines
Stall and surge in axial compressors
Fan aerodynamics
Turbulence modeling

lecture notes

1) The aim is to provide the basics for the understanding of the operation and of the aerodynamic design of the main modules of a gas-turbine-based aircraft engine. Insights on specific aspects.
2)
cc2: Tools for modeling energy/mechanical/propulsion systems and their role in supporting the analysis and design of systems and components. Understanding the organization of information in databases and computer design to support processes
cc4: In-depth study of applied thermodynamics, thermoeconomics, environmental sustainability of plants, machinery, components and systems for the production and conversion of energy. Methodologies for the identification of thermodynamic and economic inefficiencies of energy systems and components. Environmental and economic sustainability.
cc5: Applied fluid dynamics and machinery: machine components and systems for energy conversion, propulsion and design principles: from the 0D basic approach to CFD for advanced design (optimization).
3)
ca1: Ability of analysis and modeling of mechanical/electrical/propulsive components and systems: basic problems and models for industrial engineering, with special reference to mechanical and energy engineering.
ca2: Ability of applying knowledge in the field of thermofluidodynamic and machinery to solve problems of theoretical and applied thermodynamics, fluid dynamics and heat transfer.
ca4: Implement the thermofluidodynamic design of components, starting from the basic aspects (0D) up to the CFD implementation.

Fluid Dynamics, Turbomachinery, Gas Dynamics

Lectures with the aid of notes provided by the teacher.

Visit the official website on MOODLE, access is restricted, ask information to the teacher: https://e-l.unifi.it/

1) oral examination
2) The student will have to demonstrate to be able to answer theoretical questions and to have the ability to interpret the results on design problems and analysis of the performance of the components covered in the course.
3) The student will have to demonstrate to have acquired adequate knowledge of the modeling tools available to the designer (cc2, cc5) to set up appropriate analyses in order to obtain the necessary elements to understand the behavior of the components and obtain information to improve their performance (cc4) and formulate appropriate solutions (ca2, ca4)

CIVIL AVIATION:
· Introduction to strategic issues in civil aviation, ACARE goals ("Vision 2020" and "Flightpath 2050"), propulsion efficiency, specific fuel consumption, bypass ratio.
· Architecture of modern turbo fan engines (direct-drive turbo fan, geared turbo fan, contra-rotating turbo fan), unducted fan, open rotor with single or contra-rotating propellers.
· Performance comparison between a conventional direct drive turbo fan and a geared turbofan.
BOUNDARY LAYER TRANSITION:
· Transition modes:
- natural transition, linear stability theory, eN methods;
- bypass transition, intermittency function, factors that influence the transition in turbomachines, boundary layer receptivity;
- boundary layer separation-induced transition, classification and structure of the separation bubbles;
· Transition modeling: correlations for the bypass and the separation-induced transition.
· Transition in aeronautical low pressure turbines, controlled diffusion airfoils, highlift, and ultra-high-lift airfoils, wake-induced transition, multirow interaction.
· Active and passive devices for the boundary layer control.
NOISE EMISSIONS:
· Acoustic sources in aeroengines, tone noise and broadband noise
· Noise generation and propagation, noise abatement techniques
STALL AND SURGE:
· Surge and rotating stall in axial compressors
· Surge margin, parameters that affect stability
Static and dynamic instabilities
Stall inception (mode, spike)
· Casing treatments
FAN AERODYNAMICS:
· Fan aerodynamics evolution
· Turbofan, unducted fans, prop fans, counter rotating fans, direct drive turbofan, geared turbofan, military applications
TURBULENCE MODELING:
· Navier-Stokes equations, Reynolds averaging, algebraic, one-equation, and two-equation turbulence models
· Basics of large eddy simulation (LES)