## Introduction to Food Engineering

### Modes of Heat Transfer - Overview

#### Learning Outcomes

At the end of this module, you will be able to:

1. list reasons why study of heat transfer is important in food processing
2. understand difference between heat content and rate of heat transfer
3. describe the three modes of heat transfer - conduction, convection and radiation

Content

In this module, we will first examine the difference between the heat content of an object and the rate of heat transfer. In your first course in Physics, you would have learned how we determine the heat content of objects; in this course, we will extend that discussion to understand how heat transfers between different objects and the rate at which it transfers. We will then review the basic concepts of three modes of heat transfer - conduction, convection, and radiation. Learning these fundamental principles is essential in designing food processes and processing equipment.

In the following video, we will first list some reasons for the importance of heat transfer in food processing, followed by an overview of conductive heat transfer. You will learn how Joseph Fourier derived an expression useful in determining conductive heat transfer - the famous Fourier's Law.

The next video is an overview of convective heat transfer and a useful expression known as Newton's Law of Cooling.

The final video in this module is on Radiative heat transfer. Radiation plays a vital role in food processes, such as baking. Here we will consider some basic principles of radiation.

Recap

In this module, you learned three modes of heat transfer, namely conduction, convection, and radiation, and the underlying expressions that are useful in calculating heat transfer in each case.