Environmental Engineering Reference
In-Depth Information
The above geometric similarity law is not applied for the explosive with different
packing densities. If the super pressure of shock waves from explosive W
1
is
D
P at
R
1
, and the super pressure of shock waves from explosive W
2
is
D
P at R
2
, Eq.
2.78
is established.
p
3
½
R
1
R
2
¼
W
1
W
2
ð
2
:
78
Þ
p
3
W
R
D
P is a function of
,so
!
p
3
½
W
D
P
¼
f
ð
:
Þ
2
79
R
The above geometric similarity law is applied for the same explosives with
different packing density, but it is not applied for explosives with different deto-
nation heat. For explosives with different detonation heat, even with same packing
mass, the explosion effects are different at the same distance. Because of their
explosion heat is similar,
p
3
E
R
is used as a parameter. Here, E is the energy of
explosion, which is transferred into the shock waves.
!
p
3
E
D
P ¼ f
ð
2
:
80
Þ
R
Energy similarity law is applied not only in different kinds of explosives, but
is extended
p
3
E
R
also in different kinds of explosions. In general, the function f
to a polynomial
2.81
.
2
3
p
3
½
p
3
½
p
3
½
E
R
þ
B
E
E
D
P ¼ A
þ
C
ð
2
:
81
Þ
R
R
The constants A, B, and C are obtained from experiments. E ¼ WQ
V
, for TNT,
Q
V
= 4180 J/g, substitute this into
2.81
, Eq.
2.82
as below.
2
3
p
3
p
3
p
3
E
R
þ
B
1
E
E
D
P ¼ A
1
þ
C
1
ð
2
:
82
Þ
R
R
Parameter
p
3
E
R
is also one of the parameters of energy similarity. For all
explosives, all their mass can be changed into TNT equivalents.
Q
V
Q
VINT
W
E
¼ W
ð
2
:
83
Þ
