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)