Chapter 4.7, Problem 8E

(A)

Interpretation Introduction

Interpretation:

Determine the rate of entropy generation for the closed system

Concept Introduction:

Write the rate of entropy generation for the adiabatic system.

${\dot{S}}_{gen}=\dot{m}\left({\widehat{S}}_{out}-{\widehat{S}}_{in}\right)$

Here, mass flow rate is $\dot{m}$, specific entropy at outlet and inlet state are ${\widehat{S}}_{out}$ and ${\widehat{S}}_{in}$ respectively.

(B)

Interpretation Introduction

Interpretation:

Determine the rate of entropy generation for the closed system

Concept Introduction:

Write the rate of entropy generation for the adiabatic system.

${\dot{S}}_{gen}=\dot{m}\left({\widehat{S}}_{out}-{\widehat{S}}_{in}\right)$

Here, mass flow rate is $\dot{m}$, specific entropy at outlet and inlet state are ${\widehat{S}}_{out}$ and ${\widehat{S}}_{in}$ respectively.

(C)

Interpretation Introduction

Interpretation:

Determine the rate of entropy generation for the closed system

Concept Introduction:

Write the expression to calculate the rate of entropy generation.

$\begin{array}{l}0=\frac{{\dot{Q}}_H}{T_H}+\frac{{\dot{Q}}_C}{T_C}+{\dot{S}}_{gen}\\ {\dot{S}}_{gen}=-\left[\frac{{\dot{Q}}_H}{T_H}+\frac{{\dot{Q}}_C}{T_C}\right]\end{array}$

Here, rate of heat transfer to the system is ${\dot{Q}}_H$, rate of heat transfer leaves the system is ${\dot{Q}}_C$, inlet and exit temperature is $T_H\text{and}\text{}{T}_C$ respectively.

(D)

Interpretation Introduction

Interpretation:

Determine the rate of entropy generation for the closed system

Concept Introduction:

Write the expression to calculate the rate of entropy generation.

$\begin{array}{l}0=\frac{{\dot{Q}}_H}{T_H}+\frac{{\dot{Q}}_C}{T_C}+{\dot{S}}_{gen}\\ {\dot{S}}_{gen}=-\left[\frac{{\dot{Q}}_H}{T_H}+\frac{{\dot{Q}}_C}{T_C}\right]\end{array}$

Here, rate of heat transfer to the system is ${\dot{Q}}_H$, rate of heat transfer leaves the system is ${\dot{Q}}_C$, inlet and exit temperature is $T_H\text{and}\text{}{T}_C$ respectively.