progress report on spartan simulation of ife chamber dynamics farrokh najmabadi and zoran...
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Progress Report on SPARTAN Simulation of IFE Chamber Dynamics
Farrokh Najmabadi and Zoran Dragojlovic
HAPL Meeting
March 3-4, 2005Naval Research LaboratoryWashington DC
Electronic copy: http://aries.ucsd.edu/najmabadi/TALKSUCSD IFE Web Site: http://aries.ucsd.edu/IFE
Thermo-Mechanical Response of Chamber Wall Can Be Explored in Simulation Facilities
SPARTAN features: Physics: Navier-Stokes equations with state dependent transport properties;
Coronal model for radiation. Numerics: Godunov solver; Embedded boundary; and Adaptive Mesh Refinement Two-Dimensional: Cartesian and cylindrical symmetry Use results from rad-hydro codes (BUCKY) as initial condition.
SPARTAN features: Physics: Navier-Stokes equations with state dependent transport properties;
Coronal model for radiation. Numerics: Godunov solver; Embedded boundary; and Adaptive Mesh Refinement Two-Dimensional: Cartesian and cylindrical symmetry Use results from rad-hydro codes (BUCKY) as initial condition.
All previous results were based on a Bucky run provided by Don Haines
All previous results were based on a Bucky run provided by Don Haines
A variety of chamber geometries has been considered
Infinite cylinder (Cartesian symmetry)
Infinite cylinder (Cartesian symmetry)
Finite cylinder (Cylindrical symmetry)
Finite cylinder (Cylindrical symmetry)
Sphere (Cylindrical symmetry)
Sphere (Cylindrical symmetry)
Octagon(Cylindrical symmetry)
Octagon(Cylindrical symmetry)
Without Radiation, a high temperature zone would be developed in the chamber
t = 0.5 ms
Tmax = 5.3 104 K Tmax = 3.1 105 K Tmax = 2.2 105 K
t = 3 ms(After one bounce)
t = 8 ms
Tmax = 1.3 105 K Tmax = 5.1 104 K Tmax = 3.2 104 K
t = 20 ms t = 100 mst = 65 ms
Convergence of shocksleads to a hot zone.
Convergence of shocksleads to a hot zone.
Hot zone does notdisappear
Hot zone does notdisappear
Without Radiation, a high temperature zone would be developed in the chamber
0.0
0.5
1.0
1.5
2.0
2.5
3.0
0 20 40 60 80 100
time [ms]
En
ergy
[10
5 J]
Case I: No Radiation
Internal Energy
Kinetic Energy Conducted to wall
After the first “bounce” kinetic energyof gas is converted into internal energy(hot zone). Conduction to the wall is too slow.
After the first “bounce” kinetic energyof gas is converted into internal energy(hot zone). Conduction to the wall is too slow.
Case II: With Radiation
0.0
0.5
1.0
1.5
2.0
2.5
3.0
0 20 40 60 80 100
time [ms]
En
ergy
[10
5 J]
The energy is dissipated by radiation. The gas temperatureis effectively pinned byradiation (~5,000K for Xe)
The energy is dissipated by radiation. The gas temperatureis effectively pinned byradiation (~5,000K for Xe)
Internal Energy
No Radiation
Radiation
Dynamic Evolution of Xe-filled Chambers
A large number of cases with different geometries were simulated: 3-D effects can be observed and sufficiently described by using a
combination of Cartesian and axisymmetric cylindrical 2-D models. Shape of the chamber makes little difference in peaks and averages of
the temperature (< 10%). Peak Xe temperature is set by radiation at about 5,000K. A Journal article was written but is currently shelved. (see below)
A large number of cases with different geometries were simulated: 3-D effects can be observed and sufficiently described by using a
combination of Cartesian and axisymmetric cylindrical 2-D models. Shape of the chamber makes little difference in peaks and averages of
the temperature (< 10%). Peak Xe temperature is set by radiation at about 5,000K. A Journal article was written but is currently shelved. (see below)
Status of Plans from Previous HAPL Meeting
Separate radiation step from the fluid dynamics in order to shorten the run time with the full radiation source term. Done! (only a factor of ~2 reduction in run time). We purchased a two-processor 64-bit (native) computer with fast
memory access: Drastic reduction in run time. Developed MATLAB based GUI for post-processing of the data. Developed a program to construct the problem geometry from
simple geometrical shape.
Separate radiation step from the fluid dynamics in order to shorten the run time with the full radiation source term. Done! (only a factor of ~2 reduction in run time). We purchased a two-processor 64-bit (native) computer with fast
memory access: Drastic reduction in run time. Developed MATLAB based GUI for post-processing of the data. Developed a program to construct the problem geometry from
simple geometrical shape.
Parametric study of different gases (Xe, He, D, T) and initial pressures in the chamber: We received Bucky runs for chambers filled with D, T, and Xe at
10, 30, and 50 mTorr. There are significant differences between new Bucky runs and one
received from Don Haines.
Parametric study of different gases (Xe, He, D, T) and initial pressures in the chamber: We received Bucky runs for chambers filled with D, T, and Xe at
10, 30, and 50 mTorr. There are significant differences between new Bucky runs and one
received from Don Haines.
Differences between Old and New Bucky Runs (50 mTorr Xe)
0.0E+00
2.0E-07
4.0E-07
6.0E-07
8.0E-07
1.0E-06
1.2E-06
1.4E-06
1.6E-06
1.8E-06
2.0E-06
0 200 400 600 800
radius [cm]
rho
[g/c
m3
]
rho @ 5.4 E-6 srho at 500 E-6 s
-5.0E+05
0.0E+00
5.0E+05
1.0E+06
1.5E+06
2.0E+06
2.5E+06
0 100 200 300 400 500 600 700
radius [cm]
V [c
m/s
]
V @ 5.4 E-6 sV @ 500 E-6 s
Data from Don Haynes, 2001 Data from Greg Moses, 2004
Density
Velocity
-5.0E+05
0.0E+00
5.0E+05
1.0E+06
1.5E+06
2.0E+06
2.5E+06
0 100 200 300 400 500 600 700
radius [cm]
V [c
m/s
]
V @ 1 E-6 sV @ 10 E-6 sV @ 100 E-6 sV @ 500 E-6 s
0.0E+00
2.0E-07
4.0E-07
6.0E-07
8.0E-07
1.0E-06
1.2E-06
1.4E-06
1.6E-06
1.8E-06
2.0E-06
0 200 400 600 800
radius [cm]
rho
[g/c
m3
]
rho @ 1 E-6 srho @ 10 E-6 srho @ 100 E-6 srho @ 500 E-6 s
Differences between Old and New Bucky Runs (50 mTorr Xe)
0.0E+00
5.0E+00
1.0E+01
1.5E+01
2.0E+01
2.5E+01
3.0E+01
3.5E+01
0 100 200 300 400 500 600 700
radius [cm]
T [e
V]
T @ 5.4 E-6 sT @ 500 E-6 s
0.0E+00
5.0E+00
1.0E+01
1.5E+01
2.0E+01
2.5E+01
3.0E+01
3.5E+01
0 100 200 300 400 500 600 700
radius [cm]T
[eV
]
T @ 1 E-6 sT @ 10 E-6 sT @ 100 E-6 sT @ 500 E-6 s
Temperature
Data from Don Haynes, 2001 Data from Greg Moses, 2004
Comparison of SPARTAN runs using Old and New Bucky Runs as initial conditions
Temperature
Data from Don Haynes, 2001 Data from Greg Moses, 2004
Tmax = 5,370 KTmin = Twall = 973 KTave = 3,640 K
Tmax = 4,690 KTmin = Twall = 973 KTave = 3,510 K
max = 1.2 g/m3
min = 0.3 g/m3
ave = 0.4 g/m3
max = 2.9 g/m3
min = 0.5 g/m3
ave = 0.7 g/m3
Density
30m Torr D Initial Condition from Bucky
Temperature increaseswith time.
Temperature increaseswith time.
Final Words…
Regime of validity of SPARTAN: Ku = /L < 0.01 Valid Ku ~ 1 Molecular flow, not valid 0.01 < Ku < ~ 0.2 Transition (transport coefficients should be
modified) but in IFE chambers transport is dominated by radiation
50 mTorr: D = 2 cm Xe = 1 cm OK 5 mTorr: D = 20 cm Xe = 10 cm Transition
(probably OK) 0.5 mTorr: D = 2 m Xe = 1 m Molecular flow (NO)
Regime of validity of SPARTAN: Ku = /L < 0.01 Valid Ku ~ 1 Molecular flow, not valid 0.01 < Ku < ~ 0.2 Transition (transport coefficients should be
modified) but in IFE chambers transport is dominated by radiation
50 mTorr: D = 2 cm Xe = 1 cm OK 5 mTorr: D = 20 cm Xe = 10 cm Transition
(probably OK) 0.5 mTorr: D = 2 m Xe = 1 m Molecular flow (NO)
Parametric study of different gases (Xe, He, D, T) and initial pressures in the chamber: Whenever Bucky initial conditions becomes available.
Parametric study of different gases (Xe, He, D, T) and initial pressures in the chamber: Whenever Bucky initial conditions becomes available.