Main Formative objectives

The course provides the fundamentals of helicoper aerodynamics with a particular attention to the main rotor problems. The main physical phenomena and their theoretical modelling are presented, as well as the appropriate numerical and experimental investigation techniques.

Methodological Formative objectives

The methodological objectives concern both the consolidation of basic cognitive tools, and the development of interdisciplinary skills to solve complex problems by applying different hierarchical and complementary theoretical-operational approaches.

Secondary Formative objectives

Strengthening of communication and working skills in a group. Refinement of computer programming skills and experimental investigation. Development of judgment, critical analysis and comparison of results.

The expected learning outcomes of lectures are:

- the achievement of a good knowledge of the fundamental aerodynamic phenomena related to the helicopter aerodynamics;

- the capability to understand the role of aerodynamics in the general frame of helicopter design.

The expected outcomes of exercise sessions and software/experimental laboratory activities are:

- the achievement of a certain familiarity with the most classical analysis tools for rotor aerodynamics

- the awareness of limits and capabilities of these analysis tools.

- improvement of team-working skill.

Basic Rotor Aerodynamics Concepts

Review of rotor dynamics. The theory of actuator disc and blade element. Introduction to the main problems: stalling the retreating blade; the rotor wake and the "balde-vortex interaction"; the effects of compressibility. Experimental tests in the wind tunnel.

The unsteady aerodynamics of 2D airfoil

Quasi-steady theory of thin profiles. Theodorsen Theory. The indicial theory of Wagner. The dynamic stall. Experiments in the wind tunnel.

The rotor's wake

General description of the phenomena. The vortex lattice method. Navier-Stokes solvers for rotor simulations.

Acoustics

The main sources of noise produced by the helicopter.

Interactional problems

Fuselage effects on main rotor performance. Effects of the rotor wake on aerodynamic loads on the fuselage. Effects of the rotor wake on the tail planes. Interaction between the main rotor and the tail rotor.

The students are required to knows the fundamentals of aerodynamics (outcomes of the course: "Aerodinamica" or "Aerodynamics of Helicopter")  and of numerical analysis (outcomes of the course "Calcolo Numerico ed elementi di Analisi") . Furthermore the student are required to know the fundamentals of Aeronautics (outcomes of the course:"Istituzioni di Ingegneria Aerospaziale")

The exam is oral and will begin with an exposition of a topic chosen by the student (this can be a presentation of one or more lab activities carried out during the course). Questions will be asked about the presented topic and also on other parts of the program. Students will be required to be able to connect the different concepts.