Category Archives: Thermal Energy

Losses and the 2nd Law

 

 Model Description This is a demonstration designed to generate a conceptual discussion about the 2nd Law of Thermodynamics and the Kelvin-Planck statement of the law in particular.  It utilizes a pendulum to introduce the concept of irreversibilities due to friction. This demonstration should take 10-15 minutes. Engineering Principle This demonstration is based on the assumption […]

Direction of the 2nd Law

 

 Model Description This is not a hands on demonstration, but a visual aid designed to generate discussion about the Clausius statement of the 2nd Law. This activity should take 5-8 minutes. Engineering Principle The Clausius statement of the 2nd Law states “It is impossible to construct a device that operates in a cycle and produces […]

Ice Melting Blocks

 

 Model Description This demonstration illustrates the material property of thermal conductivity, and how this property affects conduction heat transfer in a solid.  Concepts include Fourier’s Law, conservation of energy and solid-liquid phase change.  This demonstration should take 8-10 minutes. Engineering Principle Fourier’s Law states that the heat transfer rate in a solid is proportional to […]

Parabolic Concentrator

 

 Model Description This demonstration illustrates how to concentrate radiant energy, solar or other, using a parabolic reflecting dish to produce high enough heat fluxes to burn paper.  This demonstration should take 10 minutes. Engineering Principle The sun is located far enough from the earth that radiation arrives here in nearly parallel beams.  A parabolic dish […]