Post on 04-Jan-2016
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COMPUTATIONAL MODELING OF PRESSURE
EFFECTS FROM HYDROGEN EXPLOSIONS
COMPUTATIONAL MODELING OF PRESSURE
EFFECTS FROM HYDROGEN EXPLOSIONS
Granovskiy E.A., Lifar V.A., Skob Yu.A., Ugryumov M.L.
Scientific Center of Risk Investigations “Rizikon“, Ukraine
Mathematical model Mathematical model
Computational model of gas cloud explosion
Total system of the time-dependent equations describing the three-
dimensional multi-component gas mixture flow
Total system of the time-dependent equations describing the three-
dimensional multi-component gas mixture flow
fzd
yc
xb
ta
TE,w,v,u,a
T2 u)PE(,uw,uv,uP,ub
T2 v)PE(,vw,vP,vu,vc
T2 w)PE(,wP,wv,wu,wd
Tgv,0,g,0,0f
The law of admixture component transfer The law of admixture component transfer
Qz
)wQ(
y
)vQ(
x
)uQ(
t
)Q(
)( gradQdiv DQ
Gas mixture explosion model
Gas mixture explosion model
mass of combustible participating in burning:
mass of combustible not participating in burning:
maxmin, QQQVQm
max0 , QQVQm
the oxidant mass in the mixture:
The mass concentrations of mixture components
total mixture mass in the volume where the burning process occurs:
min, QQVm
0mmmm
m
mQ
m
mQ 00
0QQ1
m
mQ
the excess air factor in the mixture:
Q
QQ1
m
m
0
0
0
where stoichiometric number:
m
mth0
In the case when the thermophysical properties of the gas mixture after an explosion :
1
0
c
000 QQ1QQ111
p0cp0p00p CQCQ1CQQ11C
v0cv0v00v CQCQ1CQQ11C
v
p
C
Ck
In the case when the thermophysical properties of the gas mixture after an explosion :
1
v
p
C
Ck
Q1Q1 00
c
0
0
cpcpcp CQCQ1C
cvcvcv CQCQ1C
pressure, temperature and density of gas mixture
a
0
0ua
thu PVQ
1kmQQ1HP
V
1kmHP
унmR
PVT
V
m
mathematical model verification
(experiments at Fraunhofer ICT)
mathematical model verification
(experiments at Fraunhofer ICT)
Pressure distribution in the plane XOZ near the ground (t=0.33 s)
Pressure distribution in the plane XOZ near the ground (t=0. 44 s)
Pressure distribution in the plane XOZ near the ground (t=0. 44 s)
Pressure history in the point B near the ground Pressure history in the point B near the ground
Pressure history in the point C near the ground Pressure history in the point C near the ground
Overpressure distribution in front of the shock wave (explosion of stoichiometric propane-air mixture)
1 –computational results, 2 – regressive dependence, 3 – experimental data
Overpressure distribution in front of the shock wave (explosion of stoichiometric propane-air mixture)
1 –computational results, 2 – regressive dependence, 3 – experimental data
Computation of hydrogen cloud explosion
Computation of hydrogen cloud explosion
Hydrogen cloud explosion nearby residential area
The distribution of the hydrogen volume concentration before a moment of explosion
Pressure distribution in the planes:
XOZ near the ground (a), YOZ (b)
Pressure history in the points: B (a) and C (b) explosion
Distant hydrogen cloud explosion
pressure distribution
Pressure history in the points: B (a) and C (b) explosion
Distant banked explosion of hydrogen cloud
hydrogen volume concentration distribution before a moment of the banked distant explosion
Pressure distribution
Distant partly banked explosion of hydrogen cloud
hydrogen volume concentration distribution before a moment of the partly banked distant explosion
Pressure distribution
Distant explosion partly surrounded with higher banks
hydrogen volume concentration distribution before a moment explosion
pressure distribution in the planes:
XOZ near the ground (a), YOZ (b)
Distant hydrogen explosion with the use of bumper walls
Pressure distribution in planes: XOZ near the ground (a), YOZ (b)
Pressure history in a point C
CONCLUSIONSCONCLUSIONS
The mathematical model of the gas-dynamics processes of the two-agent explosive gas mixture formation, its explosion and dispersion of the combustion materials in the open atmosphere was developed.
The finite-difference approximation was developed for the case of three-dimensional system of the gas dynamics equations complemented by the mass conservation laws of the gas admixture and combustion materials.
The algorithm of the computation of the thermo-physical parameters of the gas mixture resulting after instantaneous explosion taking into account the chemical interaction was developed.
The verification of the mathematical model showed an acceptable accuracy in comparison with the known experimental data that allowed using it for the modeling of consequences of the possible failures at industrial objects which store and use hydrogen.
The computational modeling of the gas hydrogen explosion at the fuel station was carried out.
The analysis of the different ways of protecting the surrounding buildings from the shock wave destructive impact was conducted. It was revealed that the considered types of the protective installations (partial or complete banking, bumper walls) had an influence on the pressure distribution in the computation area but did not allow bringing the maximal overpressure down to the safe level.
It was concluded that a bumper wall immediately in front of the protected object was one of the most effective protective installation. It is necessary to take into account a three-dimensional character of the shock wave in order to select safe dimensions of the protection zone around the hydrogen storage facilities.