Turbulence

Definition

Turbulence is a type of fluid flow characterized by chaotic changes in pressure and flow velocity. It contrasts with laminar flow, where fluid moves smoothly in parallel layers.

5 Must Know Facts For Your Next Test

1. Turbulent flow occurs at high Reynolds numbers, typically greater than 4000.
2. In turbulent flow, the fluid's velocity at a point varies erratically in both magnitude and direction.
3. Turbulence increases the energy loss due to friction within the fluid.
4. The transition from laminar to turbulent flow can be predicted using the Reynolds number: $Re = \frac{\rho vL}{\mu}$, where $\rho$ is density, $v$ is velocity, $L$ is characteristic length, and $\mu$ is dynamic viscosity.
5. Turbulent flows enhance mixing and heat transfer compared to laminar flows.

Review Questions

• What range of Reynolds numbers generally indicates turbulent flow?
• How does turbulence impact energy loss in a fluid system?
• Describe one key difference between laminar and turbulent flow.

Related terms

Laminar Flow: A type of fluid motion where layers do not mix; characterized by smooth paths or streamlines that are parallel to each other.

Reynolds Number: A dimensionless number used to predict the transition between laminar and turbulent flow; calculated as $Re = \frac{\rho vL}{\mu}$.

Poiseuille’s Law: (Also known as Hagen-Poiseuille equation) Describes the volumetric flow rate through a pipe due to pressure difference; applicable primarily for laminar flow conditions.