# Fluid mechanics

What does a tsunami have in common with usual surface waves? How does an airplane wing work? And why does the wind usually work against you when riding a bike (even when the wind is from the side)?

Fluid mechanics describes and explains many natural phenomena that we can see around us every day. It also has a lot of applications in industry, physics and other sciences, from astrophysics and climate science to medicine. The subject has its own distinct style, different from much other physics. This is a consequence of the central role of nonlinearities in fluid mechanics, which for example gives rise to turbulence.

The basic concepts and equations of classical fluid mechanics are introduced, and the difference between flows with very large and very small viscosity is considered.  Exact solutions for a few very simple flows are presented, as well as approximate methods for other flows. The second part of the course deals with geophysical fluid dynamics. The fluid mechanical concepts and equations are here applied to large scale flows in the atmosphere and the ocean.

• ## Course structure

The course begins with an introduction to vector analysis, the mathematical language of fluid mechanics. Then the Navier-Stokes equations are derived, and basic concepts introduced: vorticity, viscosity and Reynold's number. Some steady solutions are studied, and simplified equations for boundary layers and creeping flows. The second part of the course begins by examining flows in rotating systems. Then the properties of the rotating shallow-water equations are explored: conservation of potential vorticity, geostrophic adjustment, Poincaré waves, Rossby waves, and instabilities.

### Teaching format

The teaching consists of lectures, tutorials and laborations.

### Course material

Grading criteria, course literature and other material and correspondence related to the course will be available on the course Athena-site at https://athena.itslearning.com once you have registered for the course.

### Assessment

Cf course plan.

#### Examiner

Here is a link to a list of course coordinators and examiners.

• ## Schedule

The schedule will be available no later than one month before the start of the course. We do not recommend print-outs as changes can occur. At the start of the course, your department will advise where you can find your schedule during the course.
• ## Course literature

Note that the course literature can be changed up to two months before the start of the course.

•    Dhrubaditra Mitra, “Introduction to Fluid Mechanics” (lecture notes).
•    Geoffrey E. Vallis, “Essentials of Atmospheric and Oceanic Fluid Dynamics”, Cambridge University Press (2019).

• ## Contact

Study counselor