Explosion Features of Liquid Explosive Materials - Liquid Explosives - page 90

Fig. 2.40 The oblique re fl ection of shock waves on rigid surfaces/walls [ 21 ]

s

2

D 2 ¼ ½ ð k 1 Þ P 1 þ P 0 ð 2 : 98 Þ

q 0 k ð 1 Þ P 1 þ k ð 1 Þ P 0

The density of re fl ection shock wave fronts is Eq. 2.99 .

q 2
q 1 ¼

kP 1

ð 2 : 99 Þ

ð

k

Þ P 1 þ P 0

1

The above equations apply when P 1

40. Otherwise, the ionization of air must

P 0 \

be considered.
(2) Oblique re fl ection of air shock waves

The oblique re fl ection of shock waves occurs when the incident air shock waves

have an angle ˕ 1 with the surface of a barrier. The angle ˕ 2 between the re fl ected

waves and the surface of barrier may not be equal to ˕ 1 . D 1 and D 2 are the

transportation velocities of incident waves and re fl ected waves. Because of

re fl ection, the velocity component vertical to the surface equals zero (Fig. 2.40 ).

In Fig. 2.40 , point O moves toward the right with rate

D 1

sin u 1 on the barrier surface.

D 1
sin u 1

Moving coordinates with rate to the left are used for study and recognition of

oblique re ection shock waves are

immobile wave fronts; while the still air moves toward the right with rate q 0 ¼

fl ection. Thus, the incident shock waves and re fl

D 1
sin u 1

(Fig. 2.41 ).
In Fig. 2.41 , refers the zone in

with incident shock waves passing through and reflected shock waves not reaching;

“ O ” represents the zone of not being bothered; “ I ”