Contextualization

Thermal power is an important part of the study of physics, allowing us to understand how many mechanisms work in the world, from car engines to thermal power plants. Thermal power plays a significant role in the performance of many of our existing technologies, making its understanding essential for any student interested in the fields of engineering and sciences.

Thermal power is the amount of energy converted into heat by a heat source per unit of time, and is measured in joules per second, also known as watts (W). It is used to determine the efficiency of a thermal system, such as a power plant, where heat is used to generate electricity.

Introduction

Thermal power is a crucial part of the study of thermodynamics, a branch of physics that studies the relationships between heat, work, and energy. These concepts are fundamental to our understanding of how energy is used and converted in our world, and are the basis for the construction of many of the mechanisms we use every day.

In this project, we will explore the concept of thermal power, how it is calculated, and how it is used in practical applications. Understanding these concepts will allow students to predict the behavior of thermal systems, evaluate interventions, build prototypes, and develop problem-solving and critical thinking skills.

To delve deeper into the subject, we recommend the following reliable sources:

• Book: "Fundamentals of Thermodynamics" by Claus Borgnakke and Richard E. Sonntag. This book is an excellent introduction to thermodynamics and details key concepts such as thermal power.
• Website: Interactive Physics - Thermal Power (https://fisicainterativa.com.br). This site presents the concept of thermal power in a didactic way, with practical examples and solved exercises.
• Video: Khan Academy - Thermal Power (https://pt.khanacademy.org). Khan Academy has a series of videos on thermodynamics that are great for reinforcing and deepening knowledge on the subject.

Practical Activity

Activity Title: Thermal Power in Action - Building a Stirling Engine Prototype

Project Objective

The objective of this project is to develop a practical understanding of thermal power through the construction of a simple prototype of a Stirling engine. This type of engine is known for its thermal efficiency, making it a perfect example for the application of the concept of thermal power. By the end of the project, students should be able to calculate the thermal power of the engine and understand how this energy is converted into work.

Detailed Project Description

In this project, student groups will be challenged to build a Stirling engine prototype using common and inexpensive materials. Subsequently, they will need to calculate the thermal power generated by the engine. At the end, they will be tasked with conducting a comprehensive analysis of the engine, its efficiencies, and the implications of the obtained results for the real world.

Required Materials

• Soda cans
• Balloons
• Copper wires
• Candles
• Thermometer
• Stopwatch
• Calculator
• Measurement materials (ruler, tape measure, etc.)

Detailed Step-by-Step for Activity Execution

1. Preliminary research on Stirling engines and thermal power, including how they work and how to calculate the generated thermal power.
2. Construction of the Stirling engine using soda cans, balloons, and copper wire.
3. Testing the engine using a candle as the heat source.
4. Measuring the temperature of the heat source (you can use a thermometer for this) and the time required for the engine to operate.
5. Calculating the thermal power using the thermal power equation: P = Q/t, where P is the thermal power, Q is the thermal energy absorbed by the engine, and t is the time.
6. Analysis of the results and writing a report.

The project duration should be approximately two weeks and will be carried out in groups of 3 to 5 students.

Project Deliverables

At the end of the project, each group must deliver the following:

1. Detailed report containing:

   • Introduction: Contextualizing the theme and explaining its relevance and application in the real world.
   • Development: Where the theory on thermal power should be explained, the detailed description of the Stirling engine with schemes, photos, and/or graphics, the prototype construction process, the testing methodology, and the thermal power calculation done on the engine. Results obtained and discussion regarding them.
   • Conclusion: Presentation of the acquired learning, analysis of possible errors, and reflections on the relevance of this experience for understanding thermal power.
   • Bibliography: List of resources consulted for the project.

2. Presentation of the built Stirling engine and demonstration of its operation.

3. A short video (max 10 min) from each group presenting the prototype and explaining the construction and operation of the Stirling engine.

The focus of the project will be the practical application of the thermal power concept and the development of teamwork, problem-solving, and critical thinking skills.