Aeroengines architecture for civil aviation
Boundary layer transition in turbomachinery
Noise emissions in aeroengines
Stall and surge in axial compressors
Intakes
Fan aerodynamics
Turbulence modeling
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.
Teaching Methods
Lectures with the aid of notes provided by the teacher.
Further information
Visit the official website, access is restricted, ask information to the teacher: http://arnone.de.unifi.it/tgroup/academics
Type of Assessment
oral examination
Course program
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
· Casing treatments
INTAKES:
· Basic requirements and performance parameters definition.
· Subsonic intakes.
· Supersonic intakes, normal shocks, oblique shocks, external, mixed, and internal compression.
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)