3*L-T-P-A: (9 Credits)

Per Week Lectures:


3 (L, 50 min. each), Tutorial: 0 (T), Laboratory: 0 (P), Additional Hours [0-2]: 0 (A)

Duration of Course:


Full Semester)

Proposing Department:


Mechanical Engineering

Other departments which may be interested:


Aerospace Engineering, Chemical Engineering, Civil Engineering

Proposing Instructor:


Dr. Sachin Shinde

Other faculty interested in teaching the proposed course:


Dr. Pranav Joshi (ME department)

Course Description:


(a) Course objective: To develop the understanding of fluid mechanics of flapping foils which serve as the major thrust and lift generating appendages in swimming and flying animals, and their applications for biomimetic propulsion.


(b) Condensed Syllabus: Flapping foils in nature, airfoil theory, vortex dynamics, governing equations and parameters, kinematics, vortex wakes, drag to thrust transition, thrust by forward moving foils, unsteady actuator disk theory, efficiency estimates, scaling laws, thrust generation in quiescent ambient, deflected wakes, unsteady mechanisms, flexible flapping foils, fluid-flexible-structure interaction, 3D foils, foils in tandem, biomimetic applications.

Lecture-wise Break-up: (assuming 50 minutes lectures, total 40 Lectures)

Introduction and Fundamentals: (8 Lectures)
Flapping foils in nature; Why flapping foils?; Historical development; Vortex dynamics; Airfoil theory; Flapping foil terminologies; Fixed, Rotary Versus Flapping foils.
Thrust and Lift Generation by Flapping Foils: (15 Lectures)
Self-propelling bodies; Governing equations and parameters; Kinematics; Vortex wakes; Drag-thrust transition; Force prediction for forward moving foils; Simplified aerodynamics models; Unsteady actuator disk theory; Scaling laws; Thrust, power and efficiency estimates; Parametric study; Thrust generation in quiescent ambient; Wake deflection.
Unsteady Mechanisms: (6 Lectures)
Unsteady mechanisms for thrust and lift enhancement; Dynamic stall; Leading edge vortices; Rapid pitch-up; Wake capture; Clap and Fling; Wagner effect.
Flapping Flexible Foils: (8 Lectures)
Flexible foils in nature; Structural models; Scaling parameters; Flow-Flexible-Structure coupling; Chordwise and spanwise flexibility; Mechanisms of flow and force generation; Suppressing jet deflection; Optimal flexibility; Flexible Versus Rigid foils.
Biomimetic Propulsion and Other Topics: (3 Lectures)
Flapping foils as propulsive mechanism; Biomimetic applications in Micro Aerial Vehicles (MAVs) and Autonomous Underwater Vehicles (AUVs); Flapping foils for air & aquatic vessels; 3-D foils; Foils in tandem; Experimental techniques; Simulations; Robotic fish, bird, insect models.


(c) Prerequisite: Basic fluid mechanics, basic ordinary and partial differential equations.
Desirable: ME231, ME681, ME631 (or equivalents)
Target audience: PG and 3rd, 4th year UG students.

Books / References:

  1. An introduction to flapping wing aerodynamics – W. Shyy, H. Aono, C. Kang, H. Liu (Cambridge Aerospace Series, 2013)
  2. Fluid Mechanics – F. M. White (Tata McGraw Hill, 2008)
  3. Fundamentals of Aerodynamics – J. D. Anderson Jr. (Tata McGraw Hill, 2005)
  4. Vortex dynamics – P. G. Saffman (Cambridge University Press, 1992)
  5. Aerodynamic Theory – W. F. Durand (Julius Springer, 1935)