Hero's Engine (Rena Benor)

Author

Rena Benor

Principles

Steam engine Newton's 2nd and 3rd law of motion.

Turbines Torque

Standards

Motion and Forces

1. Newton’s laws predict the motion of most objects. As a basis for understanding this concept: a. Students know how to solve problems that involve constant speed and average speed.

c. Students know how to apply the law F=ma. (Force=mass x acceleration) to solve one-dimensional motion problems that involve constant forces (Newton’s second law).

d. Students know that when one object exerts a force on a second object, the second object always exerts a force of equal magnitude and in the opposite direction (Newton’s third law).

Materials needed

Hero's engine

water

heat source

safety glasses

Procedure

Fill the flask with a small amount of water. Wear safety glasses. Put a heat source underneath it. As the water starts to boil, the flask will start to rotate.

Explanation

Hero's Engine is today a generic name for any device which propels itself by shooting steam from one or more orifices. These devices are also known as Eolipiles. It is considered to be the first recorded steam engine or reaction steam turbine.

After filling the sphere with water, a flame is applied to it until the water boils, and the device begins to rotate.

Having oppositely bent or curved nozzles projecting from it. When the vessel is pressurized with steam, steam is expelled through the nozzles, which generates thrust due to the rocket principle as a consequence of the 2nd and 3rd of Newton's laws of motion.

The thrusts combine to result in a rotational moment or torque, causing the vessel to spin about its axis. Aerodynamic drag and frictional forces in the bearings build up quickly with increasing rotational speed (rpm) and consume the accelerating torque, eventually canceling it and achieving a steady state speed.

Questions

What must occur before the Hero's engine spins?
What does the shape and direction of the arms have to do with its motion?
How is this translated for today's machines?

Everyday examples of the principles illustrated

A steam engine is a heat engine that performs mechanical work using steam as its working fluid.Water turns to steam in a boiler and reaches a high pressure. When expanded through pistons or turbines, mechanical work is done. The reduced-pressure steam is then condensed, and it is pumped back into the boiler. Early devices were not practical power producers, but more advanced designs producing usable power have become a major source of mechanical power over the last 300 years, his power source would later be applied to prime movers, mobile devices such as steam tractors and railway locomotives. The steam engine was a critical component of the Industrial Revolution, providing the power source to propel modern mass-production manufacturing methods. Modern steam turbines generate about 90% of the electric power in the United States using a variety of heat sources.