Introduction to Heat Transfer — Lesson 3

You may have noticed cars pulled off to the side of the road, smoke emanating from under the hood.

Most automobiles are powered via an internal combustion engine that converts the chemical energy of the fuel into kinetic energy. This process is accompanied by the release of a large amount of heat which causes the temperature of the engine to rise. If the engine temperature is not regulated, it can overheat and eventually break down.

The solution to this common problem is a fluid circulation cooling system called a radiator. Fluid in the radiator passes through the engine, extracting the excess heat. The hotter fluid then travels back to the radiator where it is cooled before cycling to the engine again.

Another problem related to overheating is the loud noise coming from your laptop fan when you run a program that is computationally expensive or play a video game on high specs. Again, you are witnessing an engineering solution in action. The fan, albeit loud and overworked, helps in cooling the CPU and other electronic systems that are generating heat as they perform computations.

These are just a few examples of engineering applications that are built around transfer of thermal energy. The thermal energy in transit, or heat, always travels from the hotter medium to the colder medium. This process can occur via different mechanisms. In order to design effective cooling or heating solutions for these complex engineering problems, we need to understand the processes of heat transfer qualitatively and quantitatively.

This will be the focus of this lesson.

Alternate video link.

Here are the accompanying handout slides for the lesson.