Cengel ch06

CHAPTER

6

Entropy

FIGURE 6-1The system considered in the development of the Clausius inequality.

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

6-1


6-2

FIGURE 6-5A cycle composed of a reversible and an irreversible process.


6-3

FIGURE 6-6The entropy change of an isolated system is the sum of the entropy changes of its components, and is never less than zero.


6-4

FIGURE 6-10The entropy of a

pure substance is determined from the tables (like other properties).


6-5

FIGURE 6-11Schematic of the T-s diagram for water.

FIGURE 6-16On a T-S diagram, the area under the process curve represents the heat transfer for internally reversible processes.


6-6


6-7

FIGURE 6-19The T-S diagram of a Carnot cycle (Example 6–6).


6-8

FIGURE 6-36The isentropic relations of ideal gases are valid for the isentropic processes of ideal gases only.


6-9

FIGURE 6-37The use of Pr data for calculating the final temperature during an isentropic process.


6-10

FIGURE 6-39The use of vr data for calculating the final temperature during an isentropic process (Example 6–10).

FIGURE 6-43Schematic and T-s diagram for Example 6–12.


6-11


6-12

FIGURE 6-45P-v diagrams of isentropic, polytropic, and isothermal compression processes between the same pressure limits.


FIGURE 6-46P-v and T-s diagrams for a two-stage steady-flow compression process.

6-13


6-14

FIGURE 6-49The h-s diagram for the actual and isentropic processes of an adiabatic turbine.


6-15

FIGURE 6-51The h-s diagram of the actual and isentropic processes of an adiabatic compressor.


6-16

FIGURE 6-53Schematic and T-s diagram for Example 6–15.


6-17

FIGURE 6-54The h-s diagram of the actual and isentropic processes of an adiabatic nozzle.


6-18

FIGURE 6-61Mechanisms of entropy transfer for a general system.

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.FIGURE 6-70Graphical representation of entropy generation during a heat transfer process through a finite temperature difference.

6-19


6-20

FIGURE 6-76The electrical energy consumed by a motor is inversely proportional to its efficiency.


6-21

FIGURE 6-77The efficiency of an electric motor decreases at part load.

Documents

Cengel ch06