Due to the increase in global terror threats, many resources are being invested in efforts to find and utilize efficient protective means and technologies against blast waves induced by conventional and nonconventional weapons. Bombs exploding in the entrance of military underground bunkers initiate a blast wave that propagates in a corridor-type structure causing injuries to human and damage both to the structures and the equipment. Rigid barriers of different geometries inside a tunnel can cause the blast wave to diffract and attenuate, leaving behind it a complex flow field that changes the impact on the target downstream of the barrier. In our earlier phase of the research that dealt with a single barrier configuration, it was shown that the opening ratio (i.e., the cross section that is open to the flow divided by the total cross section of the tunnel) is the most dominant parameter in attenuating the shock wave. Additionally, it was found that when the opening ratio was fixed at 0.375, the barrier inclination angle was significantly more effective than the barrier width in attenuating the shock wave. The present phase of the research focuses on the dependence of the shock wave attenuation on a double barrier configuration, while keeping the opening ratio fixed at 0.375. The methodology is a numerical approach that has been validated by experimental results. The experiments were conducted in a shock tube using a high-speed camera. The numerical simulations were carried out using a commercial code based on an MSC-DYTRAN solver under initial conditions similar to those in the experiments. A wide span of the barrier geometrical parameters was used to map in a continues manner the effect of the barrier geometry on the shock wave attenuation. By analyzing the geometrical parameters characterizing the double barrier configuration, better understanding of the physical mechanisms of shock wave attenuation is achieved. It was shown that for a double barrier configuration, the first barrier inclination angle was very dominant in attenuating the shock wave, as expected, while the efficiency of the second barrier inclination angle depended on the distance between the two barriers. Only when the distance between the two barriers was increased and the second barrier was far enough from the first barrier, it affected the attenuation regardless of the first barrier.

References

References
1.
Dosanjh
,
D. S.
,
1956
, “
Interaction of Grids With Traveling Shock Waves
,” Technical Report NACA TN 3680, NASA.
2.
Britan
,
A.
,
Karpov
,
A. V.
,
Vasilev
,
E. I.
,
Igra
,
O.
,
Ben-Dor
,
G.
, and
Shapiro
,
E.
,
2004
, “
Experimental and Numerical Study of Shock Wave Interaction With Perforated Plates
,”
ASME J. Fluids Eng.
,
126
(
3
), pp.
399
409
.10.1115/1.1758264
3.
Sasoh
,
A.
,
Matsuoka
,
K.
,
Nakashio
,
K.
,
Timofeev
,
E.
,
Takayama
,
K.
,
Voinovich
,
P.
,
Saito
,
T.
,
Hirano
,
S.
, and
Ono
,
S.
,
1998
, “
Attenuation of Weak Shock Waves Along Pseudo-Perforated Walls
,”
Shock Waves
,
8
(
3
), pp.
149
159
.10.1007/s001930050108
4.
Britan
,
A.
,
Igra
,
O.
,
Ben-Dor
,
G.
, and
Shapiro
,
H.
,
2006
, “
Shock Wave Attenuation by Grids and Orifice Plates
,”
Shock Waves
,
16
(
1
), pp.
1
15
.10.1007/s00193-006-0019-0
5.
Franks
,
W. J.
,
1957
, “
Interaction of a Shock Wave With a Wire Screen
,” UTIA Technical Note No. 13.
6.
Lind
,
C.
,
Cybyk
,
B. Z.
, and
Boris
,
J. P.
,
1999
, “
Attenuation of Shocks: High Reynolds Number Porous Flows
,”
Shock Waves
,
G. J.
Ball
,
R.
Hillier
, and
G. T.
Roberts
, eds.,
Imperial College, London
,
UK
, pp.
1135
1140
.
7.
Baum
,
J. D.
, and
Lohner
,
R.
,
1992
, “
Numerical Simulation of Passive Shock Deflector Using an Adaptive Finite Element Scheme on Unstructured Grids
,” AIAA Paper No. 92-0448.
8.
Britan
,
A.
,
Kivity
,
Y.
, and
Ben-Dor
,
G.
,
2006
, “
Passive Deflector for Attenuating Shock Waves
,”
Shock Waves
,
G.
Jagadeesh
,
E.
Arunan
, and
K. P. J.
Reddy
, eds.,
University Press (India), Pvt Ltd
, Bangalore, India, pp.
1031
1036
.
9.
Ohtomo
,
F.
,
Ohtani
,
K.
, and
Takayama
,
K.
,
2005
, “
Attenuation of Shock Waves Propagating Over Arrayed Baffle Plates
,”
Shock Waves
,
14
(
5/6
), pp.
379
390
.10.1007/s00193-005-0282-5
10.
Kim
,
H.-D.
,
Kweon
,
Y.-H.
, and
Setoguchi
,
T.
,
2004
, “
A Study of a Weak Shock Wave Propagating Through an Engine Exhaust Silencer System
,”
J. Sound Vib.
,
275
(
3
), pp.
893
915
.10.1016/j.jsv.2003.07.008
11.
Abe
,
A.
, and
Takayama
,
K.
,
2000
, “
Attenuation of Shock Waves Propagating Over Arrayed Spheres
,”
Proc. SPIE 4183
, p.
582
.10.1117/12.424329
12.
Skews
,
B. W.
,
Draxl
,
M. A.
,
Felthun
,
L.
, and
Seitz
,
M. W.
,
1998
, “
Shock Wave Trapping
,”
Shock Waves
,
8
(
1
), pp.
23
28
.10.1007/s001930050095
13.
Chaudhuri
,
A.
,
Hadjadj
,
A.
,
Sadot
,
O.
, and
Ben-Dor
,
G.
,
2013
, “
Numerical Study of Shock-Wave Mitigation Through Matrices of Solid Obstacles
,”
Shock Waves
,
23
(
1
), pp.
91
101
.10.1007/s00193-012-0362-2
14.
Berger
,
S.
,
Sadot
,
O.
, and
Ben-Dor
,
G.
,
2010
, “
Experimental Investigation on the Shock-Wave Load Attenuation by Geometrical Means
,”
Shock Waves
,
20
(
1
), pp.
29
40
.10.1007/s00193-009-0237-3
15.
Glazer
,
E.
,
Sadot
,
O.
,
Hadjadj
,
A.
, and
Chaudhuri
,
A.
,
2011
, “
Velocity Scaling of a Reflected Shock Wave Off a Circular Cylinder
,”
Phys. Rev. E
,
83
(6), p.
066317
.10.1103/PhysRevE.83.066317
16.
Elperin
,
T.
,
Ben-Dor
,
G.
, and
Igra
,
O.
,
1987
, “
Head-on Collision of Normal Shock Waves in Dusty Gases
,”
Int. J. Heat Fluid Flow
,
8
(
4
), pp.
303
308
.10.1016/0142-727X(87)90066-X
17.
Aizik
,
F.
,
Ben-Dor
,
G.
,
Elperin
,
T.
,
Igra
,
O.
, and
Mond
,
M.
,
1995
, “
Attenuation Law of Planar Shock Waves Propagating Through Dust-Gas Suspensions
,”
AIAA J.
,
33
(
5
), pp.
953
955
.10.2514/3.12382
18.
Aizik
,
F.
,
Ben-Dor
,
G.
,
Elperin
,
T.
, and
Igra
,
O.
,
2001
, “
General Attenuation Laws for Spherical Shock Waves in Pure and Dusty Gases
,”
AIAA J.
,
39
(
5
), pp.
969
971
.10.2514/2.1405
19.
Britan
,
A.
,
Ben-Dor
,
G.
,
Shapiro
,
H.
,
Liverts
,
M.
, and
Shreiber
,
I.
,
2007
, “
Drainage Effects on Shock Wave Propagating Through Aqueous Foams
,”
Colloids Surf. A
,
309
(
1–3
), p.
137150
.10.1016/j.colsurfa.2007.01.018
20.
Shin
,
Y. S.
,
Lee
,
M.
,
Lam
,
K. Y.
, and
Yeo
,
K. S.
,
1998
, “
Modeling Mitigation Effects of Water Shield on Shock Waves
,”
Shock Vib.
,
5
(
4
), pp.
225
234
.10.1155/1998/782032
21.
Zhao
,
H. Z.
,
Lam
,
K. Y.
, and
Chong
,
O. Y.
,
2001
, “
Water Mitigation Effects on the Detonations in Confined Chamber and Tunnel System
,”
Shock Vib.
,
8
(
6
), pp.
349
355
.10.1155/2001/124019
22.
Cheng
,
M.
,
Hung
,
K. C.
, and
Chong
,
O. Y.
,
2005
, “
Numerical Study of Water Mitigation Effects on Blast Wave
,”
Shock Waves
,
14
(
3
), pp.
217
223
.10.1007/s00193-005-0267-4
23.
Igra
,
O.
,
Wu
,
X.
,
Falcovitz
,
J.
,
Meguro
,
T.
, and
Takayama
,
K.
,
2001
, “
Experimental and Theoretical Study of Shock Wave Propagation Through Double-Bend Ducts
,”
J. Fluid Mech.
,
437
, pp.
255
282
.10.1017/S0022112001004098
24.
Kosinski
,
P
.,
2006
, “
On Shock Wave Propagation in a Branched Channel With Particles
,”
Shock Waves
,
15
(
1
), pp.
13
20
.10.1007/s00193-005-0001-2
25.
Jiang
,
Z.
,
Takayama
,
K.
,
Babinsky
,
H.
, and
Meguro
,
T.
,
1997
, “
Transient Shock Wave Flows in Tubes With a Sudden Change in Cross Section
,”
Shock Waves
,
7
(
3
), pp.
51
162
.10.1007/s001930050072
26.
Kivity
,
Y.
,
Falcovich
,
J.
,
Ben-David
,
Y.
, and
Bar-On
,
E.
,
2010
, “
Dynamic Drag of a Sphere Subjected to Shock Wave: Validation of Four Hydro-Codes
,”
21st International Symposium Military Aspects of Blast & Shock, Jerusalem
,
Israel
.
27.
Ben-Dor
,
G.
,
2007
,
Shock Wave Reflection Phenomena
,
2nd ed.
,
Springer
,
Berlin
.10.1007/978-1-4757-4279-4
28.
Hoffmann
,
K. A.
, and
Chiang
,
S. T.
,
1998
,
Computational Fluid Dynamics for Engineers
, Vol.
1
,
Engineering Education System
, Wichita, KS, Chap. VI–VIII.
29.
Hoffmann
,
K. A.
, and
Chiang
,
S. T.
,
1993
,
Computational Fluid Dynamics for Engineers
-Vol.
2
,
Engineering Education System
, Wichita, KS, Chap. XVI.
30.
Berger
,
S.
,
Sadot
,
O.
, and
Ben-Dor
,
G.
,
2015
, “
Experimental and Numerical Investigations of Shock-Wave Attenuation by Geometrical Means: A Single Barrier Configuration
,”
Eur. J. Mech. -B/Fluids
,
50
, pp. 60–70.10.1016/j.euromechflu.2014.11.006
You do not currently have access to this content.