# Fluid Mechanics

### An Introduction to Fluid Mechanics

A life on earth (and probably on all possible inhabitable planets) is one lived while being constantly immersed in fluid (usually air or water). Fluid mechanics problems surround us, literally, and their study and solution is fundamental to many engineering and applied physics investigations.

Fluids are deformable to an unlimited extent, and yield in time to very small disturbance forces. Consequently, their motions are frequently very complex, and even rather straightforward fluid flow configurations can produce flow fields with nontrivial solutions displaying very complicated dynamics.

Despite the fact that the governing equations are usually well known, the vast majority of fluid flows cannot be solved directly by brute force calculation, and the subject requires a close collaboration between theory and experiment. This coupled effort, together with increasingly effective use of carefully-selected, large-scale, direct numerical simulations on the computer, results in a field which has remained vigorous, challenging and exciting for over a century.

Progress in understanding and predicting the aerodynamics of flow over wings and bodies during this time period has been spectacular, following exactly this mix of experiment and empirical discovery, together with simple and non-simple flow models. While aerodynamics is at the core of all aerospace engineering programs, the broader discipline of fluid mechanics, encompassing both aero- and hydrodynamics, covers a vast array of topics.

### Fluid Mechanics Applications

For all *bodies in motion*, there is an associated
fluid flow, whether the body is pushing against a solid
surface (automobiles, trucks, trains, cyclists, cheetahs),
or against the surrounding medium (airplanes, birds,
frisbees, ships, submarines, dolphins, fish). The body may
be *at rest in a moving fluid* (mountains, islands,
skyscrapers, ocean platforms, flagpoles, bridge towers,
pylons, trees, mussels). The fluid motion may
be *internal*, involving *transport processes*
(internal combustion engines, cooling and ventilation
systems, flows in the blood vessels and
lungs). The *scales can be very large* (planetary scale
motions -- atmospheric and ocean circulations on earth,
turbulence on galactic scales), or *very small*
(circulation and transport in micromachines, bubble and
particle motions). In many practical applications, a very
large range of scales spanning many orders of magnitude are
simultaneously present. *Flow at interfaces* between
different fluids can generate a rich set of phenomena (ocean
surface waves, oil/water mixtures in petroleum extraction,
bubbly flows, combustion and chemical mixing).

### Fluid Mechanics at USC

The range and variety of fluid mechanics problems is both breathtaking and refreshing. The diversity is reflected in the Aerospace Engineering Department at USC, which has active research and advanced teaching on many of these fronts.

### Faculty

The following faculty and research faculty are active in teaching and research in fluid mechanics at USC.

- Julian Domaradzki
- Veronica Eliasson
- Adam Fincham
- Eva Kanso
- Mitul Luhar
- Paul Newton
- Larry Redekopp
- Geoff Spedding

### Research

The primary research interest areas are listed below. Click on one of the links to learn more about each research area.

- Aerodynamics
- Computational Fluid Dynamics
- Fluid Dynamics of Biological Systems
- Geophysical Fluid Dynamics
- Nonlinear Dynamical Systems
- Turbulence