Candle by the Window: Exploring Fire Combustion and Fluid…

What the Simulation Shows

The simulation captures the intricate dance of heat transfer, fluid motion, and combustion in a hand-poured candle. As you open the window to introduce a breeze, the flame adjusts its position due to buoyancy forces, while the wax melts and flows under the influence of capillary action and Nusselt film flow. The Stefan freezing front marks where solidification occurs as the liquid wax cools.

The simulation also allows for detailed observation through lens presets and photo mode, providing a cinematic still-life that enhances understanding of these physical phenomena.

Key Physics Concepts

Buoyancy plays a crucial role in the flame's behavior. As the hot gases rise, they create a draft that can alter the flame position. Capillarity governs how wax rises through the wick due to surface tension forces. Nusselt film flow describes the heat transfer from the flame to the surrounding air and solid surfaces.

The Stefan freezing front is essential for understanding phase changes in the wax, where it transitions from liquid to solid as it cools.

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Real-World Applications

These principles are not confined to the simulation. They apply to a wide range of scenarios such as candle-making processes, fire safety, and even in industrial settings where heat transfer and fluid dynamics are critical.

Understanding these concepts can help in designing better combustion systems, improving energy efficiency, and developing safer materials for various applications.

Equations and Visuals

The simulation uses real equations to model the physical phenomena. For buoyancy, the Boussinesq approximation is used to describe fluid flow under the influence of temperature gradients. Capillary action is governed by Laplace's law, which relates the pressure difference across a curved liquid surface to its curvature.

Nusselt film flow is described by Nusselt numbers that quantify convective heat transfer relative to conductive heat transfer. The Stefan condition describes the rate at which phase change occurs.

Frequently asked questions

How does the breeze affect the flame?

The breeze affects the flame by creating buoyancy forces that cause it to lean towards the direction of the draft, altering its position and stability.

What is capillarity and how does it work in this simulation?

Capillarity refers to the ability of a liquid to flow in narrow spaces without the assistance of, or even in opposition to, external forces. In the simulation, it causes wax to rise through the wick due to surface tension.

Why is understanding Nusselt film flow important?

Understanding Nusselt film flow is crucial for analyzing heat transfer processes in various applications, including combustion and industrial cooling systems.

How does the Stefan freezing front work?

The Stefan freezing front describes the boundary between liquid and solid wax as it cools. It helps in understanding how phase changes occur during the melting and solidification processes.

Try it live

Everything above runs in your browser — open Candle by the Window: Wax Flow, Breeze and Cinematic Still-Life Lab and change the parameters while it is running. Nothing is installed, nothing is uploaded, the whole model lives in one tab.

▶ Open Candle by the Window: Wax Flow, Breeze and Cinematic Still-Life Lab simulation

Candle by the Window: Exploring Fire Combustion and Fluid Dynamics