Elements of Propulsion: Gas Turbines and Rockets
With worked examples, numerous homework problems, illustrations and pictures, this book provides a complete introduction to gas turbine and rocket propulsion for aerospace and mechanical engineers.
TABLE OF CONTENTS Elements of Propulsion: Gas Turbines and Rockets
Chapter 7: Parametric Cycle Analysis of Real Engines
Supporting Material for this chapter is available electronically. See page 869 for instructions to download.
7.1 Introduction
In Chapter 5, we idealized the engine components and assumed that the working fluid behaved as a perfect gas with constant specific heats. These idealizations and assumptions permitted the basic parametric analysis of several types of engine cycles and the analysis of engine performance trends. In Chapter 6, we looked at the variation of specific heat with temperature and fuel/air ratio and developed component models and figures of merit. This allows us to use realistic assumptions as to component losses and to include the variation of specific heats in engine cycle analysis. In this chapter, we develop the cycle analysis equations for many engine cycles, analyze their performance, and determine the effects of real components by comparison with the ideal engines of Chapter 5. We begin our analysis with the turbojet engine cycle and treat the simpler ramjet engine cycle as a special case of the turbojet ( ? c = 1, ? c = 1, ? t =1, ? t = 1).
7.2 Turbojet
We will now compute the behavior of the turbojet engine including component losses, the mass flow rate of fuel through the components, and the variation of specific heats. Our analysis still assumes one-dimensional flow at the entrance and exit of each component. The variation of specific heats will be approximated by assuming a perfect gas with constant specific heat c pc upstream of...
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