The Power of Steam

Steam engines were the main driving force of the Industrial Revolution. After two centuries, they were eventually replaced by other, more efficient, and more economical machines. Nevertheless, steam still plays a very important role in the production of electricity in thermal and nuclear power plants.

Learning Objectives:

• Learn about the history of industrial use of steam.
• Understand how the energy of steam can create motion.
• Create a practical simulation of motion produced by the power of steam.

Keywords: Steam, Steam Engine, Steam Turbine, Generator

Duration: 5 minutes

Begin the lesson with a short discussion to introduce the topic:

• Have your students ever seen a steam locomotive or another steam-powered machine?
• Do they have any idea how such devices worked? What was needed to power them?
• Why are they no longer used?

Duration: 10 minutes

In Alexandria in the first century AD lived a Greek mathematician and engineer named Hero (or Heron). He invented the predecessor of what we would later call the steam engine. It was a simple device he named the Aeolipila, derived from the Greek name “Aiolos,” the god of wind. Similar devices may have existed before Hero’s Aeolipila, but he was the first to record the design in his book Pneumatica, which describes many other ingenious mechanisms.

The Aeolipila, Hero’s device, used heat from burning fuel to vaporize water and then used the hot steam to create rotational motion. This simple mechanism anticipated later steam engines but was forgotten for centuries until it was revived in the early modern period by Taqi al-Din and later by other scientists in various parts of Europe. However, Corinth has not forgotten this invention! To see Hero’s creation, open the Corinth application, go to the Physics library, and find the model “Aeolipila.”

Play the model’s animation to show the class how it works. The burning wood heats and vaporizes the water in the vessel. The resulting steam increases the pressure in the metal sphere mounted on an axis above the tank. The sphere has two opposing nozzles through which steam is released into the air. The force of the escaping steam causes the sphere to rotate on its axis. Explain this process to your students and highlight the different parts of the model!

Duration: 15 minutes

Hero’s invention was rediscovered after a long period of forgetfulness and disinterest, roughly 1,500 years later during the Ottoman period, by Taqi al-Din. Later, in different parts of Europe during the first half of the 17th century, various inventions appeared that worked with the power of steam. The idea spread further in the second half of the century when the first real prototypes of future machines appeared in the form of steam pumps. Finally, the 18th century became the true era of steam engine development and construction. Newcomen’s and Watt’s engines are the best known and most widely used innovations in the field of steam.

The growing demand for energy in industry, mining, and transportation led to massive use of new technologies to provide the required power, replacing previously used sources such as human or animal labor or natural forces like wind or water. Many variations of steam engines appeared, but the key innovation is attributed to James Watt. The most important components of modern steam engines are the piston and cylinder, along with the concepts of vacuum and pressure.

In the Corinth application, you can discover how a simple steam engine works. Open the Physics library and find the model “Steam Engine.” Open it and show it to your students!

If the model does not load, open it in a new window:
app.corinth3d.com/content/f_vyna_parni_stroj

When you click on the “Steam Engine – Section” part, you will see all the details of the engine’s internal arrangement. Describe all its parts and their functions — especially how the valve moves and how the piston’s motion is caused by the expansion of hot steam. By the end of this part of the lesson, students should understand how the power of steam, generated by heating water through the burning of fossil fuels such as coal, can be used to create motion, which was harnessed by industrial machines.

Duration: 15 minutes

Thanks to the invention of other energy sources, the use of steam engines gradually decreased during the 20th century and was replaced by cheaper and more efficient sources of energy. Nevertheless, steam is still used to drive turbines for electricity generation. These turbines are part of all power plants where heat is converted into motion and subsequently into electricity, such as thermal or nuclear power plants.

To explain how such a turbine works and how it helps in electricity production, use models in the Corinth application! Go to the Physics library and open the model “Boiling Water Reactor”, which shows how water in the reactor is heated until it evaporates.

If the model does not load, open it in a new window:
app.corinth3d.com/content/f_vyna_jaderny_reaktor

Then continue by opening the model “Nuclear Power Plant”, which shows the entire water circuit in nuclear power stations. Draw students’ attention to the different parts and explain how water is converted into steam, enters the turbine, causes the shaft to rotate, and then exits and condenses back into liquid form.

If the model does not load, open it in a new window:
app.corinth3d.com/content/f_vyna_jaderna_elektrarna

Finally, if you want to better explain how a rotating shaft can generate electricity, you can do so with the help of the model “Three-Phase Generator”, which clearly demonstrates how electricity can be generated.

If the model does not load, open it in a new window:
app.corinth3d.com/content/f_vyna_3f_generator

Duration: 15 minutes

In this experiment, you will try to construct your own Aeolipila!

Required Tools:

• An unused aluminum beverage can
• Water
• Laboratory stand
• Laboratory burner
• String
• Needle

Procedure:

1. Use the needle to pierce the beverage can on one side, approximately in the middle of the cylinder.
2. Pour out the liquid from the can. Then pierce the can a second time directly opposite the first hole. Turn the needle 90° in both holes (in the same direction, e.g., to the right) and remove it.
3. Fill the can with water through the small holes you created, as the can should remain sealed.
4. Prepare the laboratory stand and string, and hang the can filled with water from it. Place the laboratory burner underneath.
5. Light the burner and wait until the water inside the can starts to boil. Once it begins to evaporate, steam will escape through the holes, and the can will begin to spin. Your Aeolipila works!

Conclude the lesson with a short discussion:

• Could we somehow replace the role of steam in electricity production? How?
• Do students think steam-powered vehicles or devices have any future? Why (or why not)?