About the Course

What is fluid-solid interactions ? It is what happens when the motions of a fluid and of a solid are somehow coupled. This happens all the time, around you when leaves flutter in the wind, inside you when your heart beats, above you when wings of a plane vibrate, under the sea.

The idea behind this MOOC is to give you the basic tools to be able to predict and eventually mitigate things called flutter, galloping, sloshing, vortex-induced vibrations, added mass, to cite a few.

We are going to consider any possible domains of applications such as civil engineering, aerospace engineering, nuclear engineering , ocean engineering, biomechanics and even food processing !

This is why we called the course “fundamentals of Fluid solid interactions ”. There are so many phenomena and so many models that we need to work together on the basic mechanisms .

If you want to see how fluid-solid interactions work, and be able to use that knowledge, join us !

Course Syllabus

1. Dimensional analysis of fluid-solid coupling

   • The variety of fluid-solid couplings
   • Dimensional analysis as a classification tool
   • Dimensionless numbers in fluid-solid interactions
   • From dimensionless numbers to dimensionless equations

2. A solid with a still fluid.

   • Low reduced velocities
   • Small motions and low reduced velocities
   • Fluid-added Stiffness
   • Neglecting viscous effects
   • Fluid-added mass.

3. A solid with any fluid.

   • Dominant effects of viscosity
   • Fluid-added damping
   • Combined effects of fluid viscosity
   • Memory effects
   • Fluid sloshing
   • Coupling of fluid sloshing with solid dynamics

4. Coupling with a fast flow.

   • High reduced velocities
   • Flow-induced static instabilities, or buckling
   • Coupled-mode flutter of airfoils.

5. Coupling with a slow flow.

   • Intermediate reduced velocities
   • Flutter on one mode
   • Stall flutter of airfoils
   • Galloping of bluff bodies

6. Coupling with any flow.

   • The fluid conveying pipe as a reference model of coupling
   • Coriolis damping
   • Solution for any flow velocity
   • From one mode to two modes
   • Vortex-induced vibrations
   • Lock-in as a case of coupled-mode flutter

Suggested Readings

The lecture are self-contained, but the students will find useful additional information in the following book in paperback : Païdoussis, M. P., Price, S. J., & de Langre, E. (2011). Fluid-structure interactions: Cross-flow-induced instabilities Cambridge University Press. 

A textbook in French also contains material closely related to the content of the course de Langre, E. (2002). Fluides et solides. Editions Ecole Polytechnique.