Dr. Ashok Gopalarathnam

Dr. Ashok Gopalarathnam

Mechanical and Aerospace Engineering

Phone: 919-515-5669
Fax: 919-515-7968
Instructor Website
Research Website

MAE 551 Airfoil Theory

3 Credit Hours

Development of fundamental aerodynamic theory. Emphasis upon mathematical analysis and derivation of equations of motion, airfoil theory and comparison with experimental results. Introduction to super sonic flow theory.


Undergraduate course in aerodynamics or fluid mechanics and differential equations or consent of instructor.

Course Objectives

After this course, the student will be able to explain the fundamental characteristics of subsonic airfoils and the connection between surface pressure distributions and the lift, drag, and pitching moment generated by the airfoil. The student will be able to discuss the effect of pressure distributions on the growth of the boundary layer and the resulting viscous effects. The assignments will help the student develop an understanding of the effect of geometry characteristics of the airfoil on the aerodynamic behavior. The student will be able to use thin airfoil theory and codes such as XFOIL to analyze airfoils and discuss the results. The student will be able to design subsonic airfoils using inverse design techniques.

Course Requirements

Homework: Approximately three homework assignments

Quizzes: Quizzes on Moodle, typically after every three or four lectures

Examinations: One open-book, take-home final exam

Software Requirement: Need Matlab and some familiarity with Matlab to run the MFOIL code, basic programming skills required (Fortran, C, C++, Matlab, or similar programming language)

Projects: Two airfoil design projects and three short blog posts

Course Topics

Overview of airfoil characteristics

Development of thin airfoil theory

Airfoil analysis using XFOIL

Multipoint inverse airfoil design using PROFOIL and MFOIL codes

Natural laminar flow and low Reynolds number airfoils

Effect of airfoil characteristics on aircraft performance

Adaptive airfoils

High-lift airfoils

Introduction to conformal mapping

Introduction to transonic airfoil aerodynamic


John D. Anderson, Fundamentals of Aerodynamics, 5th Edition, McGraw Hill. ISBN: 9780073398105. Recommended, not required. (Textbook for MAE 355 Aerodynamics I — highly recommended for students who do not have a degree in Aerospace Engineering.) Earlier editions or other similar textbooks (on aerodynamics) will also work.

J. Katz and A. Plotkin, Low-Speed Aerodynamics, Second Edition, Cambridge University Press, 2001. ISBN-10: 0521665523 | ISBN-13: 9780521665520. Recommended reference book, not required.

Computer and Software Requirements

One of the projects requires access to Matlab and a Windows PC (to run an executable for an airfoil design code compiled for a Windows PC).

Please review minimum computer specifications recommended by NC State University and Engineering Online.


Updated 4/6/2020