Mini Stirling Engine

Evidence of Work

For my project, I wanted to demonstrate the concept of energy transformation using a Mini Stirling Engine powered by an alcohol burner to light up an LED. The goal was to convert chemical energy (fuel) into thermal energy, then mechanical energy, and finally into electrical energy. I began by collecting materials including a small alcohol burner, 70% isopropyl alcohol, a mini Stirling engine, an LED light, and alligator wires. The process required me to set up the engine on a heat-resistant platform, attach the LED light, and ignite the alcohol burner under the displacer cylinder to begin the energy transformation process.

In the first trial, I experienced minor issues with stability and flickering in the LED. I resolved these by improving wire connections and burner alignment. I also experimented with different alcohol concentrations, determining that 70% isopropyl alcohol provided the most consistent and safe results. The final setup involved a stable wooden base, proper burner placement, and a high-efficiency white LED for better visibility. The engine successfully demonstrated visible energy transformation: the LED illuminated steadily while the engine ran.

Content Explanation of Major Concepts

1. Energy Transformation
Energy transformation refers to the process of converting one form of energy into another. In my project, chemical energy from burning alcohol transformed into thermal energy, which then became kinetic energy inside the engine, and finally electrical energy to power an LED. This chain of energy conversions is a fundamental concept in physics and helped reinforce how systems can harness fuel for useful work.

2. Thermal Energy and Heat Transfer
Thermal energy is the energy that comes from heat. The alcohol flame heated the air inside the Stirling engine’s cylinder. This heat caused the air to expand and contract, moving the piston. According to the Collision Theory, increased thermal energy increases particle collisions, which was essential in driving the engine's internal mechanisms.

3. Mechanical Energy and Motion
Mechanical energy is the energy of moving parts. As thermal energy moved the piston, the flywheel began spinning. The flywheel’s motion converted heat into mechanical energy, which was the driving force behind the LED generating electricity.

4. Electrical Energy and Circuits
Electrical energy was the final output of the system. When the flywheel turned, it transferred motion to a tiny generator (or alternator) that lit the LED. This demonstrated how kinetic energy can be used to power basic electrical components.

5. Cross-Subject Integration
This project tied into chemistry concepts (combustion reactions, isopropyl alcohol concentration), engineering principles (design and stability), and math (energy output estimation). Using equations such as:

• Heat Energy = Power × Time → 100 J/s × 90 s = 9,000 J

• Electrical Energy = Power × Time → 0.04 W × 30 s = 1.2 J These calculations highlighted how different subject areas support scientific exploration.

Reflection

Peaks / Positives:
One thing I did well was troubleshooting during each trial, especially improving the burner positioning to stabilize the LED light. This showed Critical Thinking and Creativity, two elements of the Graduate Profile. I also improved my ability to explain physical processes with real-world examples, which enhanced my Communication skills. For instance, I could clearly walk classmates through the energy chain from chemical to electrical.

Another strength was learning how to safely and effectively manage a live flame in a controlled experiment. This demonstrated my growth in Character and Citizenship, as I took lab safety seriously and responsibly managed each step of the procedure.

Pits / Areas for Growth:
One challenge I faced was time management. I didn’t account for the time needed to make multiple trials and modifications. As a result, my final documentation felt rushed. In the future, I’ll use better Planning and Organization strategies, such as scheduling buffer days and making a checklist.

Another area I need to improve is collaboration. Although I completed this mostly independently, I realized that brainstorming solutions with classmates could have improved my design faster. I’ll work to build better Collaboration habits by actively seeking peer feedback in future group projects.