1. Introduction to Turbulence

2. Fluids
A substance that has no fixed shape and yields easily to external pressure
Fluids are divided into 2 types:
Liquids
Gases

3. Can you think of the differences between fluids and gases?

4. Easiest way to distinguish liquids and gases:
If I try and move it from one container to another (i.e. by pouring), will it take on the shape of the new container?
Liquids will take the shape of the container!
A gas will fill any container, but if the container is not sealed, the gas will escape!

5. Demonstration Take 3 containers A short glass A long glass
A wide container
Pour water from one to the other? Discuss what you observe!

6. Laminar Vs Turbulent Flow
Laminar Flow:
The fluid flow is very orderly i.e fluid layers move parallel to each other and do not cross each other
Turbulent Flow:
The fluid flow is not orderly i.e. there is mixing of adjacent layers of fluid with each other

7. Characteristics of turbulent flow
Think about opening a faucet in your house
Can you think of both turbulent and laminar regimes?
What causes change from laminar to turbulent flow in this case?
What are some characteristics of turbulent flow that you observe?
Think about other examples of turbulent flow!
What are the characteristics of turbulent flow?

8. Characteristics of turbulent flow
Chaotic/Random
Rotational

9. Characteristics of turbulent flow
Enhances Mixing
Enhances Dissipation

10. Applications of Turbulent Flow

11. Has any one experienced turbulence while on a flight
Has any one experienced turbulence while on a flight? Describe your experience!

12. Approaches to study turbulence
Theory
Experiment
Computer Simulations

13. Turbulence is a hard problem to solve!
"I am an old man now, and when I die and go to heaven there are two matters on which I hope for enlightenment. One is Quantumelectrodynamics and the other is the turbulent motion of fluids. About the former I am rather optimistic."
-Horace Lamb
`Turbulence is the most important unsolved problem of classical physics.'
- Richard Feynman -

14. Turbulence is a hard problem to solve!
The Millennium Prize Problems are seven problems in mathematics that were stated by the Clay Mathematics Institute in It offered a US $1,000,000 prize to the first person providing a solution for a specific statement of the problem.
One of the problems is related to turbulence!
What tools/areas should you become proficient at if you want to give it a try?

15. Image References 3.
Lecture Notes, Andy Bragg, Duke University