Visualizing turbulence

What is the main challenge in predicting turbulent motion?

• The motion is linear and simple.

• The motion is too slow to observe.

• The motion is too predictable.

• The motion is chaotic and complex.

What is a vortex ring?

• A stable doughnut-shaped region of fluid.

• A flat circular motion of particles.

• A linear flow of water.

• A chaotic swirl of air.

How does turbulence differ from laminar flow?

• Turbulence is confined to distinct layers.

• Turbulence is smooth and predictable.

• Turbulence is a type of laminar flow.

• Turbulence involves chaotic and swirling eddies.

What are the Navier-Stokes equations used for?

• Describing the motion of solid objects.

• Calculating the speed of light.

• Predicting the behavior of gases only.

• Describing fluid dynamics.

What is a key characteristic of turbulence according to the Navier-Stokes equations?

• It is unrelated to fluid dynamics.

• It is easy to solve.

• It is predictable and linear.

• It involves chaotic and complex patterns.

What does Kolmogorov's hypothesis suggest about energy in turbulent flow?

• Energy is not present in turbulent flow.

• Energy cascades from large to small scales.

• Energy is evenly distributed across all scales.

• Energy is only present at large scales.

What is the inertial subrange in the context of Kolmogorov's hypothesis?

• A range of length scales where energy distribution is predictable.

• A range where energy is absent.

• A range where only large eddies exist.

• A range where turbulence is not observed.

What is the significance of the 5/3 power in Kolmogorov's hypothesis?

• It describes the size of eddies.

• It represents the speed of light.

• It is a fundamental constant of turbulence.

• It is unrelated to fluid dynamics.

What is vortex stretching?

• A process where vortices shrink in size.

• A process where vortices expand in two dimensions.

• A process where rotating fluid stretches perpendicular to its rotation plane.

• A process where fluid stops moving.

How does energy transfer differ in 2D and 3D turbulence?

• In 3D, energy is static.

• In 2D, energy moves from small to large scales.

• In 3D, energy moves from small to large scales.

• In 2D, energy moves from large to small scales.