GOTHIC: Overview TL George Numerical Applications, Inc

2 GOTHIC 7.2 General Purpose Thermal-Hydraulic Analysis Special Modeling Features for Containment Building Modeling Ongoing Development and Maintenance Support by the EPRI GOTHIC Enhancement Project (since 1993).

3 Multi-Zone Modeling Combine Lumped and Subdivided Volumes Superimposed Conductors Finite Volume Solution Semi-explicit Implicit Thermal Conductors Junctions Components Lumped Volumes Subdivided Volume Boundary Conditions F P

4 Multiphase/Multicomponent Vapor Steam N Gas Components Drops Liquid Films Pools Slugs Mist Ice Pool Lumped Subdivided

5 Equation Set

6 Interphase Heat and Mass Transfer Evaporation Condensation Diffusion Layer Model for Noncondensing Gas Effects Boiling/Flashing Drop Entrainment Drop Deposition Ice Melt Steam Injection Air Bubble Condensing Steam Bubbles Water

7 Wall Heat Transfer and Condensation Free Convection Forced Convection Radiation Wall - Steam Wall - Wall Condensation Uchida Tagami Gido-Koestel Mist/Diffusion Layer Model F1D and 2D Conduction

8 Mixing Buoyant Flows Forced Convection Jet Induced Mixing Diffusion Molecular Turbulent - k-e Model Mass Diffusion - Vapor Thermal Diffusion - Vapor/Liquid Momentum Diffusion - Vapor/Liquid Vent Steam Plume Source

9 Hydrogen Combustion Recombiners Lumped Parameter HECTR Model User Specified Propagation Subdivided Volume Calculated Propagation Laminar Turbulent Eddy Diffusivity Model 3D H2 Burn in a Box Igniter x z Y=0 Y=Mid

10 Equipment Models Pumps/Fans Valves Vacuum Breakers Heat Exchangers Fan Coolers Igniters Recombiners Heaters/Coolers Spray Nozzles FControls l Trips l Forcing Function l Control Systems

11 Networks Consist of Links and Nodes Full Implicit Solution Two-phase Homogenous Equilibrium Flow Heat Addition/Extraction at Nodes Connect to Lumped Volumes Subvolumes Boundary Conditions Piping and Duct Networks Tank System Ventilation

12 Subdivided Volumes Volume and Area Porosity Factors to Model Obstructions and Irregular Boundaries Slip/No-Slip Boundaries Easy User Interface

13 3D Connectors Connect Subdivided Volumes to Lumped Volumes Subdivided Volumes Embedded Grids Full 3D Momentum Solution Diffusion Across Connection 3D Connectors at interface between coarse and fine grids.

14 Multiple Detail Levels

15 Advanced Wall Condensation Model Sensible Heat Transfer Free Convection Forced Convection Radiation to Steam Mass Transfer Mass Transfer Coefficient from Heat/Mass Transfer Analogy Mist Formation in the Boundary Layer TvTv T sat Subcooling y mm

16 Comprehensive Drop Behavior Models Drop Breakup Hydrodynamic Forces Flashing General Entrainment Model Relative Velocity Film/Pool Thickness Fluid Properties Depositions Models Diffusion Turbulent Impaction Bends WALE Test Drop Concentration

17 Solution Methods Conductor Solution Full implicit finite volume Fluids Solution Semi-implicit finite volume Full-implicit finite volume 1 st and 2 nd order upwind differencing options Multigrid, Conjugate Gradient, Block Iterative and Direct Matrix solution options.

18 Applications Heating and Cooling Forced Convection Natural Convection Radiation Evaporation and Condensation Boiling HVAC system performance

19 Applications EQ Analysis EQ Environment Thermal Lag Room Heatup Containment Pressure and Temperature Line Breaks in Auxiliary Buildings Multiphase Flow in Piping Systems Water Hammer Cooler Performance

20 Applications Hydrogen Distribution Recombiners Burn Spent Fuel Pool Performance Hydrodynamic Loads on Equipment Hazardous Gas Migration Special Investigations …

21 Assessment Current Test Matrix Includes 204 Tests 96 Functional Tests 53 Comparison with Analytic Results 22 Separate Effects Experiments 32 Combined Effects Experiments Includes 4 from International Standard Problems

22 Enhancements in Progress Tracked component in the liquid phase Liquid component Solid particles with settling Multiple drop fiel Parallel Processing Distributed computing on multinode system for faster run speed Additional Assessment

23 Quality Assurance GOTHIC is maintained under NAI’s QA Program. Conformance to 10CFR50 Appendix B requirements. Meets intent of ASME NQA-1 Built in QA features Event Logging File Comparison Utility

24 More Information Animations for CFD simulations