Chapter 6 Key Concepts

Water is relatively dense and viscous.
The Reynolds number is an estimate of the relative importance of viscous and inertial forces in a fluid.
Whatever is part of the flow will not cross streamlines in a flowing fluid.
Laminar flow is regular, whereas turbulent flow is irregular.
Turbulence has different effects at different spatial scales.
As a fluid moves over a solid surface, very near the surface, velocity steadily decreases with depth, the water reaching a standstill at the solid surface.
Water flow over a surface can be turbulent.
The principle of continuity allows one to calculate flow velocity in a biological circulatory system.
Bernoulli’s principle states that pressure varies inversely with fluid velocity.
Water moving past an object creates drag, a force that operates differently at different Reynolds numbers.
Hydrodynamic forces often present conflicting constraints.
Flumes are useful for studying the effects of moving fluids on organisms, although flumes must be scaled carefully.