Heat Engine, Carnot Efficiency, and Sample Problem

Abstract

The material presented in this lecture is adapted from Chapter 4 of T&M. First, we will continue our discussion of the heat engine introduced in Lecture 7, including deriving an expression for the efficiency of a heat engine. We will then show that the efficiency of a heat engine can never be 100% and will discuss what determines the upper limit. Second, we will introduce an ideal heat engine which operates fully reversibly, known as the Carnot engine. We will show that even for the Carnot engine, the efficiency is less than 100%. Third, we will discuss the theorem of Carnot and the Corollary to this theorem. Fourth, we will solve Sample Problem 8–1 to analyze the Carnot cycle for an ideal gas, including using this cycle to calculate the efficiency of a Carnot engine. Finally, we will present the Theorem of Clausius.