Aerodynamics

Duration

30h Th, 28h Pr, 2h Labo., 25h Proj.

Number of credits

Lecturer

Thomas Andrianne, Vincent Terrapon

Coordinator

N...

Language(s) of instruction

English language

Organisation and examination

Teaching in the second semester

Units courses prerequisite and corequisite

Prerequisite or corequisite units are presented within each program

Learning unit contents

Aerodynamics is the study of fluid flows around or within solid bodies. One of the major objectives of aerodynamics is to predict the forces and moments that are exerted by the fluid on the body, or to predict the heat transfers between the fluid and the body. Classically, aerodynamics has mostly focused on the calculation of lift and drag forces on simple airfoils or even complete aircrafts. Determining the aerodynamic forces and moments are a critical step in the design of an aircraft. Aerodynamics is thus an essential topic in the curriculum of aerospace engineers. 
This course presents the most fundamental aspects of aerodynamics. It focuses mostly on low-speed (incompressible) aerodynamics, but also briefly introduces some elements of compressible aerodynamics. Following topics are covered:

• Aerodynamic forces and moments: lift and drag, pitching moment, airfoil polar, aerodynamic center, center of pressure
• Incompressible potential flows, singularities (vortex, source, doublet), d'Alembert principle, circulation
• Superposition of fundamental solutions, Rankine oval, lifting cylinder, Kutta-Joukowski theorem, conformal mapping, complex formalism, Joukowsky airfoil
• Thin airfoil theory: line distribution of singularities, effect of thickness and camber, Kutta condition
• Panel methods: potential-based, vortex-based, source-based, equivalence between source, doublet and vortex-based methods
• 3D wings: vortex sheet, Prandtl lifting line theory for large aspect ratio wings, distribution of circulation, induced drag, downwash velocity, elliptic lift distribution, optimal wing, general lift distribution
• Boundary layers: concepts and definitions, boundary conditions, thickness, von Karman integral equation, flow separation and airfoil stall, transition to turbulence
• Laminar boundary layer: self-similar solution (Blasius, Falkner-Skan), Pohlhaussen method, Thwaites method
• Turbulent boundary layer: transition, characteristics, Reynolds-averaging, Head method, log law
• Compressible aerodynamics: compressible potential flow, Prandtl-Glauert equation, flow past a thin airfoil (subsonic, transonic, supersonic)

Learning outcomes of the learning unit

At the end of the course, the students should be able to:

• Compute the aerodynamic forces and moments on a profile from a velocity or pressure distribution
• Differentiate between the sources of drag, their cause and characteristics
• Simplify important equations using dimensional analysis
• Calculate the potential flow around a profile using the method of singularities and conformal mapping
• Calculate the aerodynamic forces on a airfoil profile using the thin airfoil theory
• Understand the link between singularities and panel methods
• Calculate the inviscid aerodynamic forces on a three-dimensional wing from its two-dimensional characteristics
• Calculate the boundary layer from the potential flow solution
• Determine the best approach to compute the boundary layer (self-similar profile, integral method, ...)
• Compare experimental measurements, with theoretical and/or numerical results
• Differentiate between the physics of laminar and turbulent flows
• Determine the characteristics of transition to turbulence and flow separation from the pressure distribution and Reynolds number
• Average important equations using Reynolds approach
• Estimate the aerodynamic forces in the supersonic and transsonic regimes for thin airfoils
• Apply the concepts seen in class to other topics

Prerequisite knowledge and skills

To efficiently follow this course, it is preferable to have some basic knowledge in fluid mechanics (e.g., MECA0025 "Mécanique des fluides") and in mathematics (e.g., MATH0007 "Analyse mathématique II").

Planned learning activities and teaching methods

Each week, the course relies on both a formal lecture taught by the instructors, during which the theoretical concepts are described and explained, and an exercise session led by the assistant, whose objective is to illustrate and consolidate the theory through practical exercises. The solution to each problem set is available through the course website the following day. However, students are highly encouraged to actively solve the problem sets as it is the best way to learn the material.
Learning activities also include an integrated exercise by groups of 3 or 4 students. It consists in a one-time wind tunnel laboratory session, where aerodynamic forces are measured on a wing model, and a theoretical part, where the potential flow and boundary layer around the wing are calculated. Results are then summarized in a written report. This integrated exercise allows the application of the theory seen in class to a concrete case and the comparison between theoretical, numerical and experimental results.
The report of the integrated exercise is graded. Moreover, the participation in the laboratory is mandatory. Students who have not taken part in the laboratory will not be admitted to the exam.

Mode of delivery (face-to-face ; distance-learning)

Both the theoretical lectures and the exercise sessions are taught in class face-to-face. A podcast of each theoretical lecture and exercise session is available one day later on myULg and the course website.
Special arrangements are provided to students of the THRUST master.

Recommended or required readings

The mandatory reference book is:

• "Fundamentals of Aerodynamics", John Anderson Jr., 5th edition, McGraw and Hill, ISBN 978-0-07-339810-5

Assessment methods and criteria

For the 1st session, the final grade is obtained from two contributions:

• Written exam (exercises and theory): 70%
• Integrated exercise in groups: 30% (based on a written report)

Work placement(s)

Organizational remarks

The course is jointly taught by Prof. Terrapon and Dr. Andrianne.
Lectures take place each Tuesday afternoon between 13h30 and 15h30. Each lecture is followed by an exercise session from 15h30 to 17h30. The exact weekly schedule and important deadlines are communicated during the first lecture.
Special arrangements are provided to  students of the THRUST master.

Contacts

Students are encouraged to actively interact with the instructors, also outside of the lectures. It is recommended to set up an appointment first. For questions regarding the exercise sessions and the laboratory, the students can also contact directly the assistant. 
It is expected that the students follow a few basic rules when communicating by email: 

• Indicate as subject "AERO0001: ...".
• Only use ULg addresses (xxx@student.ulg.ac.be).
• Always address emails to both lecturers and not only to one.
• Follow the elementary rules of politeness.