Page 23 - 《含能材料》2018年优秀论文

Experimental Study and Numerical Simulation of CL‑20‑Based Aluminized Explosive in Underwater Explosion 689

mum radius was larger with addition of aluminum the temperature of products will rise gradually.
powder. When the bubble radius reached maximum When temperature of products reached a certain
（t =25.5 ms，R =67.6 cm），the pressure inside the value，the hotter products generated light. The bub‑
bubble reached minimum. The bubble radius ble of CL‑20‑based explosive had no the secondary
reached minimum at t=50.2 ms. As Fig. 6 shown， reaction. It had no enough heat to make the prod‑
when the time was from 49.5 ms to 49.8 ms，the ucts generate light.
light is produced in the bubble of sample 4 . 3.3 Underwater Explosion Energy and Its
#
Calculation
3.3.1 Specific Shock Wave Energy
The shock wave energy released by explosives
explosion is related to peak pressure and time of
pressure acting. The shock wave formula can be de‑
scribed as follows：
p ( ) t = p m e -t/θ （1）
Where p（t）denotes the pressure with change of
time t，Pa；p is the peak pressure in primary shock
m
Fig. 5 Experimental pictures of bubble pulse for sample 4 # wave，Pa；θ is the time constant in the shock wave，
s. The time constant θ is defined as the time it takes
for the pressure to decay from its peak value p to
m
value p /e，i.e.，0.37 p ，s.
m
m
4πR 2 τ
E = K ( ρ C W ) ∫ 0 p ( ) t 2 dt （2）
s
e
W
K e = 1 + 0.29γ + 0.016γ 2 （3）
Fig. 6 Experimental pictures of bubble pulse for sample 4 #
γ = d （4）
For aluminized explosive mixtures，the reaction of C ⋅ θ
W
aluminum particles occurs behind C‑J reaction zone ［36］ . e = E - E' - E ″ s （5）
s
s
Then，the activated aluminum particles react with s W
detonation products under high temperature and Where K e is the correction factors of shock
high pressure，which include lots of oxidizing gas‑ wave energy；R denotes the distance from sensor to
es，such as H O，CO ，and CO. This is called the the center of charge，m；ρ is the density of water at
W
2
2
-3
secondary reaction of an aluminized explosive ［37］ . charge depth，kg·m ；C W is the sound speed of wa‑
-1
In addition to the above reaction，aluminum parti‑ ter at charge depth，m·s ；d is the diameter of pres‑
cles can react with nitrogen in detonation products sure‑sensitive part of the gage，m；θ is the time con‑
to produce aluminum nitride under high temperature stant，s；E is the shock energy at measuring point，
s
and high pressure ［38］ . The secondary reaction will re‑ J；E' denotes the shock energy by booster charges at
s
lease energy in the products expansion region after measuring point，J； E ″ is the shock energy by No. 26
s
the detonation state for hundreds of microseconds. electric detonator at measuring point，J；e denotes
s
When the time was from 49.5 ms to 49.8 ms，the the shock energy per kg explosives at measuring
secondary reaction was over completely at that time. point，J·kg ；W denotes the charge mass of explo‑
-1
The light in bubble was caused by high temperature sive，kg.
products. Because of aluminum particles can react 3.3.2 Specific Bubble Energy
with explosion products to give out a lot of heat ， The major effects of the bubble generated from

CHINESE JOURNAL OF ENERGETIC MATERIALS 含能材料 2018 年 第 26 卷 第 8 期 （686-695）