Post on 15-Jan-2016
description
transcript
T.G. Theofanous
Center for Risk Studies and Safety University of California, Santa Barbara
STEAM EXPLOSIONS
Risk Complexity
An Approach Based on Key Physics (ROAAM)
m-FLUID PREMIXTURE
vO, PO
COOLANTVAPORFUEL
(melt)NON-PARTICPATING COOLANT
Multiphase Thermal Detonation: MicrointeractionsMultiphase Thermal Detonation: Microinteractions
Propagation Key Physics
ESPROSE.m Verification
Physics Numerics
• Space/Time Discretization
• Numerical Diffusion
• Artificial Viscosity
Analytical
•Exact Solutions for Steady
Detonations (C-J)
•Effect of Idealizations in Exact Solutions
•2D/3D Code Comparison
Integral Aspects
Experimental
• KROTOSAnalytical
• Characteristics Solutions in 1D Geometries
• Exact Solutions in 2D Geometries
Wave Dynamics
• SIGMA
-Single and
Two-Phase
- Multiple regions
Explosion Coupling
Experimental
Analytical
• Characteristics Solutions for Coupled Explosion/Reflection at Free Surfaces
• SIGMA
Constitutive Laws
for Microinteractions
Experimental
rR
H
z
Water Level
Explosion Zone
pSource of radius R
VERIFICATION OF ESPROSE.m CODE
Both DNS and Effective-Field
Ex-Vessel Explosion
EX-VESSEL EXPLOSION
ESPROSE.m Results in the P-v plane
in Relation to Shock Adiabat and the Hugionot
Premixing Key Physics
Penetrative Thermal Radiation
Multifield and Multidimensional
Large Scale Discontinuities
Evolving Melt Length Scales
Eulerian-Lagrangian. No numerical diffusion
Characteristics-Based Matching with MuSiC
Flexibility in “Laws” of Breakup
used to Envelop Premixtures of Risk Significance
PM-ALPHA Verification
Physics Numerics
• Space/Time Discretization
• Numerical Diffusion
Code Comparison
• CHYMES
• PM-ALPHA.3D
Multifield Aspects
Integral Aspects
Experimental
• MIXA
• FARO
Breakup Aspects
Analytical
• Single Particle
• Drift Flux
Experimental
• Single Particle
• MAGICO
• QUEOS
3D Multi-field modeling (4 fields: water, steam, fuel, debris)
Closure laws (flow regimes, boiling heat transfer regimes, momentum transfer, breakup)
VERIFICATION OF PM.ALPHA.L CODE
Representative frames from PM-ALPHA.L simulations Representative frames from PM-ALPHA.L simulations of QUEOS runs Q6, Q8, and Q10of QUEOS runs Q6, Q8, and Q10
Illustration of flow regimes and effect of subcooling as Illustration of flow regimes and effect of subcooling as depicted by PM-ALPHA.L simulations of representative depicted by PM-ALPHA.L simulations of representative
MAGICO runsMAGICO runs
All frames are at 0.3 s following initial contact with water.