Future Plans
Michael T. Heath
Professor and Director
12 September 2001
©2001 Board of Trustees of the University of Illinois
Center for Simulation of Advanced Rockets
University of Illinois at UrbanaChampaign
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Center for Simulation of Advanced Rockets
University of Illinois at UrbanaChampaign
©2001 Board of Trustees of the University of Illinois
Y6

10
Multiscale simulations
Improved physical modeling
Multiphysics coupling
Verification and validation
3
Center for Simulation of Advanced Rockets
University of Illinois at UrbanaChampaign
©2001 Board of Trustees of the University of Illinois
Fluid Dynamics
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Center for Simulation of Advanced Rockets
University of Illinois at UrbanaChampaign
©2001 Board of Trustees of the University of Illinois
Two

Phase Flow
Burning Aluminum with Smoke
Crude droplet burning model
No support for slag build

up
No subgrid effects for particles,
combustion, etc.
5
Center for Simulation of Advanced Rockets
University of Illinois at UrbanaChampaign
©2001 Board of Trustees of the University of Illinois
Validation
of
Rocturb
Ad hoc turbulence injection model
No two

phase flow effects in model
Simple subgrid models
Inadequate agreement with experimental
turbulence data
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Center for Simulation of Advanced Rockets
University of Illinois at UrbanaChampaign
©2001 Board of Trustees of the University of Illinois
Fluids
—
Multiscale Simulations
Spatial multiscale: Generalized LES
Further “Optimal LES” turbulence development
Combustion “LES”
Radiation “LES”
Lagrangian particles and super particles
Temporal multiscale
Time zooming formulations
High order, high resolution, optimal
numerics (for LES)
Adaptive grids for turbulence simulation
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Center for Simulation of Advanced Rockets
University of Illinois at UrbanaChampaign
©2001 Board of Trustees of the University of Illinois
Fluids
—
Improved Physical Modeling
Real gas effects
Thermal and chemical non

equilibrium
Nozzle and plume physics
Aluminum particle combustion
Based on detailed single

particle simulations
Acoustic coupling
Hydrodynamic instabilities
Combustion instabilities
Multi

phase flow
Slag accumulation
Agglomeration and break

up
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Center for Simulation of Advanced Rockets
University of Illinois at UrbanaChampaign
©2001 Board of Trustees of the University of Illinois
Fluids
—
Multiphysics Coupling
Injection from combustion layer
Turbulent fluctuations
Aluminum droplets
Particle combustion
Fluid

structure in deforming/complex
geometry
Inhibitor and crack propagation
Hybrid structured/unstructured grid
Inhibitor and nozzle scouring and
ablation
Grid generation, motion, and remeshing
9
Center for Simulation of Advanced Rockets
University of Illinois at UrbanaChampaign
©2001 Board of Trustees of the University of Illinois
Fluids
—
V&V
Automated verification test suite
Regular periodic testing of developing code
Expanding domain of testing
Component model validation against DNS
LES & CPR
Particle combustion and single

particle DNS
Characterizing solution uncertainties
Uncertainties from modeling, input data, numerics
Integration of physical data
Simulation validation against available data
NASA, Thiokol, ONERA, …
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Center for Simulation of Advanced Rockets
University of Illinois at UrbanaChampaign
©2001 Board of Trustees of the University of Illinois
Fluids
—
Experiments
Optical flow
measurements in
propellant combustion
flow
Turbulence and particle
distribution
Detailed fluid measurements in
combustion

driven flows
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Center for Simulation of Advanced Rockets
University of Illinois at UrbanaChampaign
©2001 Board of Trustees of the University of Illinois
Combustion and
Energetic Materials
12
Center for Simulation of Advanced Rockets
University of Illinois at UrbanaChampaign
©2001 Board of Trustees of the University of Illinois
f(x,y,t)
z
Current: single

valued
Level sets/ghost fluid?
(collaboration with CS)
Future: multivalued
CEM
–
Surface Propagation
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Center for Simulation of Advanced Rockets
University of Illinois at UrbanaChampaign
©2001 Board of Trustees of the University of Illinois
CEM
–
Turbulence Seeding
Time

dependent
mass flux from
propellant provides
boundary conditions
for turbulent
chamber flow
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Center for Simulation of Advanced Rockets
University of Illinois at UrbanaChampaign
©2001 Board of Trustees of the University of Illinois
CEM
—
Multiscale Simulations
Average 3

D condensed phase equation
to get 1

D model
Use
Rocfire
to modify
Rocburn
Use DNS to construct models for averaged terms
Turbulence seeding
Erosive burning
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Center for Simulation of Advanced Rockets
University of Illinois at UrbanaChampaign
©2001 Board of Trustees of the University of Illinois
CEM
—
Improved Physical Modeling
Complex kinetics
Gas

phase
Condensed

phase
Level

set methods for
steep or over

hanging
propellant surfaces
Fuel

rich packs
Aluminum pooling and injection
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Center for Simulation of Advanced Rockets
University of Illinois at UrbanaChampaign
©2001 Board of Trustees of the University of Illinois
CEM
—
Multiphysics Coupling
Effects of flow on burning
Erosive burning
Ignition transients and flame spread
Turbulence seeding
Injection of igniting aluminum droplets
Burning in cracks
Surface propagation
17
Center for Simulation of Advanced Rockets
University of Illinois at UrbanaChampaign
©2001 Board of Trustees of the University of Illinois
CEM
—
V&V
Sandwich

propellant experiments
Flame structure
Surface structure
Regression rate
Composite

propellant data
Average regression rate
Unsteady response, pressure coupling
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Center for Simulation of Advanced Rockets
University of Illinois at UrbanaChampaign
©2001 Board of Trustees of the University of Illinois
CEM
—
Multiscale Simulations
Path integral Monte Carlo for thermal
simulations of quantum systems
Ab initio molecular dynamics (Car

Parrinello) simulations of materials
Excited states and quantum reaction
dynamics in molecules
Combining the methods
Thermal simulations of matter using quantum
Monte Carlo
First principles calculations of reaction dynamics
Density functional simulations for large systems
High pressure non

molecular phase of
nitrogen

density
functional simulation

compared with
experiments
Nature 411, 170 (2001)
CEM
—
Multiscale Simulations
Shock data for hydrogen
comparison of PIMC simulations
with NOVA laser shock
experiments and SESAME EOS.
Science 281, 1178, 1998.
Decomposition pathways
of ethylene
Embedding
Force models
Continuum mechanics
Extend to
heavier atoms
Longer time
scales
Longer time
scales
20
Center for Simulation of Advanced Rockets
University of Illinois at UrbanaChampaign
©2001 Board of Trustees of the University of Illinois
CEM
—
Improved Physical Modeling
Improved methods
Improved functionals using quantum Monte Carlo methods
Extending quantum Monte Carlo to heavier atoms
Embedding of methods for multiscale simulations
Reaction dynamics calculations embedded in regions simulated
by density functionals and continuum mechanics
Time scale

the hardest problem
Hyperdynamics and beyond for atomic scale simulations
Integration into kinetic Monte Carlo for reactions
21
Center for Simulation of Advanced Rockets
University of Illinois at UrbanaChampaign
©2001 Board of Trustees of the University of Illinois
Structures and
Materials
Constitutive Modeling of SP
Currently: Arruda

Boyce
8

chain rubber elasticity model
Developed for unfilled and filled
rubbery materials
Nonlinear kinematics
Material stiffening
Simplicity
Still missing
Rate dependence (Bergstrom

Boyce)
Microstructural damage and
fracture mechanisms
Dewetting
Void growth
Binder tearing
Integration of multiscale models
30
20
10
1.0
2.0
3.0
4.0
5.0
Stretch
Nominal stress
(MPa)
23
Center for Simulation of Advanced Rockets
University of Illinois at UrbanaChampaign
©2001 Board of Trustees of the University of Illinois
Structures
—
Multiscale Simulations
Molecular, granular, and structural
modeling of case and SP
Adaptivity in
Rocsolid
and
Rocfrac
Spatial adaptivity through mesh refinement
Dynamic remeshing and repair
Dynamic insertion of cohesive elements
Implementation of 4

D space

time FE
scheme
24
Center for Simulation of Advanced Rockets
University of Illinois at UrbanaChampaign
©2001 Board of Trustees of the University of Illinois
Structures
Improved Physical Modeling
Implement history

dependent constitutive
models in ALE
formulation
Extend SP constitutive
theory to failure regime
Modeling of nozzle
ablation and scouring
25
Center for Simulation of Advanced Rockets
University of Illinois at UrbanaChampaign
©2001 Board of Trustees of the University of Illinois
Structures
—
Multiphysics Coupling
Mesoscale structure/combustion
modeling of advancing crack
Macroscale modeling of fracture events
with
Rocflu/Rocfrac
Mesh generation
Implicit/explicit coupling strategies
26
Center for Simulation of Advanced Rockets
University of Illinois at UrbanaChampaign
©2001 Board of Trustees of the University of Illinois
Structures
—
V&V
Benchmark verification problems
Expand library of known benchmark problems
Develop methods to create new benchmark
problems to test complicated modules (e.g., ALE)
Verification of coupled codes
Validate codes
Thiokol failure data on model SP motors
Lab

scale rocket data
Quasi

static and dynamic properties of SP and case
(D6AC steel) under tension and compression
Methods to deal with model uncertainty
and sensitivity
27
Center for Simulation of Advanced Rockets
University of Illinois at UrbanaChampaign
©2001 Board of Trustees of the University of Illinois
Computer Science
28
Center for Simulation of Advanced Rockets
University of Illinois at UrbanaChampaign
©2001 Board of Trustees of the University of Illinois
Software Framework Challenges
Full exploitation of object decomposition
Load balance within individual phases
Source code changes for AMPI
10K

100K processors
Inadequate load balancing strategies
Automatic optimization of object communication
Component frameworks
Dynamic insertion support for FEM
Component frameworks for other common abstractions
Integration of modules
Complex orchestration code
Optimized parallel data exchange
29
Center for Simulation of Advanced Rockets
University of Illinois at UrbanaChampaign
©2001 Board of Trustees of the University of Illinois
CS
—
Frameworks
Software integration
Intelligent interface between modules
Intelligent handling of dynamic
behavior
Adaptivity
Load

balancing
Support for choice of coupling
strategies
Support for spawning subscale
simulations
Components
Application

aware data structures
FEM, multiblock, AMR, particles, …
Solid
HDF IO
Fluid
Roccom
Orchestration
Combustion
Interface
30
Center for Simulation of Advanced Rockets
University of Illinois at UrbanaChampaign
©2001 Board of Trustees of the University of Illinois
CS
—
Computational Infrastructure
Computational steering
Autopilot
On

the

fly performance
analysis and visualization
Pablo
Panda/Globus
integration
for Grid
Remote visualization of
ultra large data sets
Scalability issues for
100K processors
31
Center for Simulation of Advanced Rockets
University of Illinois at UrbanaChampaign
©2001 Board of Trustees of the University of Illinois
Challenges in Computational
Mathematics and Geometry
Independent meshing capability
Mesh adaptation and repair
Robust and efficient propagation
of moving interface in 3

D
Interpolation extended to 3

D for
remeshing, etc.
Robust and scalable solvers for
ill

conditioned, nonsymmetric
systems
32
Center for Simulation of Advanced Rockets
University of Illinois at UrbanaChampaign
©2001 Board of Trustees of the University of Illinois
CS
Improved Computational Techniques
Computational geometry
Dynamic mesh repair
On

the

fly remeshing
Interpolation between 3

D meshes
Interface surface propagation in 3

D
Computational mathematics
Iterative solvers for ill

conditioned systems
Application

specific preconditioners
Grid

based solvers
33
Center for Simulation of Advanced Rockets
University of Illinois at UrbanaChampaign
©2001 Board of Trustees of the University of Illinois
Integrated
Simulations
34
Center for Simulation of Advanced Rockets
University of Illinois at UrbanaChampaign
©2001 Board of Trustees of the University of Illinois
GEN3
Multiscale simulations
Homogenization
Time zooming
Dynamically

spawned subscale simulations
Improved physical modeling
Propellant ignition and tailoff
Real gas effects
Slag formation
Nozzle and inhibitor ablation and scouring
Plume
Environmental effects
35
Center for Simulation of Advanced Rockets
University of Illinois at UrbanaChampaign
©2001 Board of Trustees of the University of Illinois
GEN3
Multiphysics coupling
Modules coupled using SWIFT
External modules (inbound)
Technology transfer (outbound)
V&V
Normal burns
Accident scenarios
Thrust vector control (3

D effects)
Additional rocket designs
NASA five

segment Shuttle booster
Center for Simulation of Advanced Rockets
University of Illinois at UrbanaChampaign
©2001 Board of Trustees of the University of Illinois
http://www.csar.uiuc.edu
©
37
Center for Simulation of Advanced Rockets
University of Illinois at UrbanaChampaign
©2001 Board of Trustees of the University of Illinois
Michael T. Heath, Director
Center for Simulation of Advanced Rockets
University of Illinois at Urbana

Champaign
2262 Digital Computer Laboratory
1304 West Springfield Avenue
Urbana, IL 61801 USA
m

heath@uiuc.edu
http://www.csar.uiuc.edu
telephone: 217

333

6268
fax: 217

333

1910
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