TITLE.PM5

(Ann) #1

GAS POWER CYCLES 641


dharm
\M-therm\Th13-3.pm5


Putting the value of T 2 in eqn. (ii), we get
T

T
r

3

1

β =()γ− 1

T 1 =

T
r

3
1

1
β γ
.
()−
Now inserting the values of T 1 , T 2 , T 4 and T 5 in eqn. (i), we get

η

ρ ρ
β

β
γρ

ρ
β

β
γρ

γ
γ γ γ
dual

..
()

()

()
()

=−

F
HG

I
KJ −

L


N


M
M

O


Q


P
P
F −
HG

I
KJ

+−
L
N

M


O
Q

P


=−

F −
HG

I
KJ
F −
HG

I
KJ

+−


− −
1

1

1

11

1 1 1

3

1
3
1

3 3 33

1
T
r

T
r

T T TT

r

i.e., η βρ
γ ββγρ


γ
dual ().

(. )
[( ) ( )]

=− −
− −+ −
1 11
r^111

...(13.10)
Work done is given by,

W = p 3 (v 4 – v 3 ) + pv^44 pv^55 pv^22 pv^11
11



− −
γγ−

= p 3 v 3 (ρ – 1) +
()pv prv43 53()pv prv23 13
1

ρ
γ

−−−

=

pv pv p
p
rpv p
p
33 43 5 r
4

23 1
2

11 1

1

()()ργ ρ

γ

−−+ −
F
HG

I
KJ

−−
F
HG

I
KJ

Also p
p

v
vr

5
4

4
5

=F
HG

I
KJ

=F
HG

I
KJ

γ ρ γ
and p
p

v
v

(^2) r
1
1
2
=F
HG
I
KJ


γ
γ
also, p 3 = p 4 , v 2 = v 3 , v 5 = v 1
∴ W = vp^33 p^3 r p r
1
2
11 11
1
[()()( )( )]
()
ργ ρρ
γ
−−+ −γγ− −γ

−−


pv 22 11 r^111 r
1
[( )( ) ( ) ( )]
()
βρ γ β ρ ρ
γ
−−+−γγ−−γ

−−


pr vr 11 11 r^11
1
() /[ (γγβγ ρ ) (β ) (βργ)]
γ
−+ −− −


pvr 11 1111 r 1
1
γγβγ ρ β βργ
γ
−−−+ −− −

[( )( ) ( )]
...(13.11)
Mean effective pressure (pm) is given by,
pm = W
vv
W
v r
r
pv r r
v r
r
(^121)
11
11
1
1
11 1
− 1 1


F −
HG
I
KJ
= −+ −− −
− FHG − IKJ
[()()()]−−
()
γγβγ ρ β βργ
γ
pm =
pr r
r
1
111 1
11
()[ ( ) ( ) ( )]
()()
γγβρ β βργ
γ
−+ −− −
−−

...(13.12)

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