Biophysics For Dummies

Chapter 10

Going with the Fluid Flow — Fluid Dynamics

In This Chapter

Distinguishing different fluids

Staying in the air

Fighting the viscosity

Spinning in a centrifuge

Fluid dynamics is the study of flowing fluids. All liquids and gases are considered fluids, so fluid dynamics plays an important role in many areas of biophysics. An understanding of fluid dynamics is particularly important in the study of blood flow in the body and in airflow in the lungs, the flight of birds, weather patterns in meteorology, and environmental science.

All fluids have internal friction between the molecules and also friction with the boundaries containing the fluid. Friction is the force that resists motion and arises from the electromagnetic force between the molecules of the fluid and between the molecules of the fluid with the atoms and molecules forming the container. The frictional force within a fluid is called viscosity. (Think of maple syrup, which has a high viscosity compared to water, which has a low viscosity.) This chapter focuses on two situations: nonviscous fluids and viscous fluids. ...