Environmental Engineering Reference
In-Depth Information
2.4.3 Explosion of Liquid Explosives in Semienclosed Space
[
22
,
24
26
]
-
The explosion of liquid explosives releases more gases. The super pressure of
explosion on the ground within 0.5
1.0 m is lower than condensed explosives.
But the detonation positive pressure impacts longer time than condensed explo-
sive, especially the places, which are far from the explosion center, for example,
the zone outside of explosion reactions. The explosions of liquid explosives are
more powerful in semienclosed space, especially in semiunderground or under
ground.
-
2.4.3.1 Re
fl
ection of Shock Waves from Rigid Barriers
When the air shock waves of explosion from liquid explosive meet the vertical rigid
wall (barrier), the velocity of air mass points drops down to zero suddenly, which
accumulates the mass point, and the pressure and density increase dramatically until
certain degrees. Then the mass points re
ect to the opposite direction, the reverse
shock waves are produced. Semienclosed space is different from free space. The
superposition of reverse waves rises the pressure to an extremely high level.
(1) Explosion from the re
fl
fl
ection of shock waves
ection of shock waves when they meet the vertical rigid
unlimited walls. If the incident waves are one-dimensional steady ones, the refec-
tion waves are also one-dimensional steady waves. The parameters of air are
P
0
;
T
0
; q
0
; m
0
¼
Figure
2.38
gives the re
fl
0 before being bothered and the parameters of incident wave
fronts are, P
0
; q
1
;
T
1
;
m
1
. Because the wall is absolutely rigid, the air particles
close to the wall are in a stationary state before re
and
ection. When shock waves meet
the rigid wall, the air particles near the wall produce the re
fl
fl
ection waves with
velocity/speed D
2
. The direction of re
fl
ection waves is the opposite of incident
waves. The parameters of re
fl
ection wave fronts are P
2
;
T
2
; q
2
and
m
1
¼
0 because
of the rigidity of the wall.
From the basic functions of shock waves, below equations are obtained.
Fig. 2.38 The re
fl
ection of shock waves in semienclosed space when liquid explosives explode
