Understanding Fluid Dynamics in a Snow Globe

What is Fluid Dynamics?

Fluid dynamics is the study of fluids (liquids and gases) in motion. It encompasses the behavior of liquids and gases as they flow through various environments, influenced by forces such as gravity, pressure gradients, and external mechanical actions like shaking or stirring.

In a snow globe, fluid dynamics explains how the water behaves under different conditions, from its initial state to the final resting position of each snowflake.

Turbulence vs. Laminar Flow

When you shake the snow globe, the sudden disturbance causes turbulence in the fluid, where particles move chaotically and unpredictably. This is in contrast to laminar flow, where fluid moves smoothly without mixing or eddies.

As the shaking stops and gravity takes over, the fluid transitions from a turbulent state to a more stable laminar flow, allowing each snowflake to settle gently at its own pace.

Forces Acting on Snowflakes

Several forces act on the snowflakes within the snow globe. Gravity pulls them downward, while viscous drag from the fluid opposes their motion and slows them down as they fall.

The balance between these forces determines how quickly each flake settles to the bottom of the globe.

Controlling Fluid Dynamics

By adjusting sliders for snow density, gravity, fluid drag, flake size, and toggling auto-shake on or off, you can explore different scenarios that illustrate how these factors influence the dynamics of the system.

For example, increasing the fluid drag slider will slow down all flakes more uniformly, while changing the snow density affects how many flakes are present in the globe.

Frequently asked questions

Try it live

Everything above runs in your browser — open Snow Globe Fluid Dynamics (2D) and change the parameters while it is running. Nothing is installed, nothing is uploaded, the whole model lives in one tab.