AMS 599
Special Topics in Applied
Mathematics
Lecture 4
James Glimm
Department of Applied Mathematics
and Statistics,
Stony Brook University
Brookhaven National Laboratory
Turbulent mixing for a jet in
crossflow and plans
for turbulent combustion
simulations
The Team/Collaborators
•
Stony Brook University
–
James Glimm
–
Xiaolin Li
–
Xiangmin Jiao
–
Yan Yu
–
Ryan Kaufman
–
Ying Xu
–
Vinay Mahadeo
–
Hao Zhang
–
Hyunkyung Lim
•
College of St. Elizabeth
–
Srabasti Dutta
•
Los Alamos National
Laboratory
–
David H. Sharp
–
John Grove
–
Bradley Plohr
–
Wurigen Bo
–
Baolian Cheng
Scramjet Project
–
Collaborated Work including Stanford PSAAP Center, Stony Brook
University and University of Michigan
Schematics of the transverse injection of an under
-
expanded jet into a supersonic crossflow
•
Structures expected: bow shock, counter
-
rotating vortex
pair, recirculation zones, large scale structures on the jet
surface
Outline of Presentation
•
Problem specification and dimensional
analysis
–
Experimental configuration
–
HyShot II configuration
•
Plans for combustion simulations
–
Fine scale simulations for V&V purposes
–
HyShot II simulation plans
•
Preliminary simulation results for mixing
Main Objective
•
Compare to the Stanford code development
effort. Chemistry to be computed without a
model (beyond dynamic turbulence model).
Hereby we can offer a UQ assessment of the
accuracy of the Stanford code.
•
If the comparison is satisfactory and the two
codes agree, the UQ analysis of the Stanford
code (in this aspect) will be complete.
–
Applications to the UQ program
Problem Specification and
Dimensional Analysis
•
Simulation Parameters: Experimental Configuration
–
Fine grid: approximately 60 micron grid
•
Mesh = 1500 x 350 x 350 = 183 M cells
–
If necessary, we can simulate only a fraction of the experimental
domain
–
If necessary, a few levels of AMR can be used
–
Current simulations = 120 microns, about 10 M cells
•
HyShot II configuration
–
Resolution problem is similar
•
3/4 volume after symmetry reduction compared to experiment
–
Full (symmetry reduced) domain needed to model unstart
–
Resolved chemistry should be feasible
–
Wall heating an important issue
Flow and Chemistry Regime
•
Turbulence scale << chemistry scale
–
Broken reaction zone
•
Autoignition flow regime
–
T
c
<< T
–
Makes flame stable against extinction from turbulent fluctuations
within flame structure
•
Unusual regime for turbulent combustion
–
Broken reaction zone autoignition distributed flame regime
–
Query to Stanford team: literature on this flow regime?
•
Knudsen and Pitsch Comb and Flame 2009
•
Modification to FlameMaster for this regime?
–
Opportunity to develop validated combustion models for this
regime, for use in other applications
•
Some applications of DOE interest
Flow, Simulation and Chemistry
Scales; Experimental Regime
•
Turbulence scale << grid scale << chemistry scale
•
Turbulence scale = 10 microns
•
<< grid scale = 60 microns
•
<< chemistry scale 200 microns
•
Resolved chemistry, but not resolved turbulence
•
Need for dynamic SGS models for turbulence
•
Transport in chemistry simulations must depend on
turbulent + laminar fluid transport, not on laminar
transport alone
Simulation Plans:
HyShot II Regime
•
Compare to laboratory experimental regime and
resolved chemistry simulations (V&V)
•
Simulate in representative flow regimes defined by the
large scale MC reduced order model, both for failure
conditions (unstart) and for successful conditions.
•
Provide improved combustion modeling to the MC low
order model, for the next iteration of an MC full system
search.
•
Investigate “gates” which serve to couple system
components into full system
–
For combustion chamber: fuel nozzle, inlet flow and exit nozzle
•
Exactly how can the “gate” be defined to achieve the decoupling?
–
Essential step for relating UQ of components to UQ of full
system
Preliminary Simulation Results:
Mixing Only
3D simulation. 67% H
2
mass concentration
isosurface plot compared to experimental
OH
-
PLIF image (courtesy of Mirko Gamba).
The grid is 120 microns, 2 times coarser
than the Intended fine grid mesh size.
Preliminary Simulation Results:
Mixing Only
Black dots are the flame front
extracted from the experimental
OH
-
PLIF image.
Preliminary Simulation Results:
Mixing Only
Velocity divergence plotted at the midline plane. Bow shock, boundary layer
separation, barrel shock and Mach disk are visible from the plot.
Preliminary Simulation Results:
Mixing Only
H
2
mass fraction contour plotted at the midline plane
Preliminary Simulation Results:
Mixing Only
Stream
-
wise velocity
contour plotted at the midline plane
Preliminary Simulation Results:
Mixing Only
H
2
mass fraction contour plotted at x/d=2.4
Preliminary Simulation Results:
Mixing Only
Stream
-
wise velocity
contour plotted x/d=2.4
Preliminary Simulation Results:
Mixing Only
Comparison between Smagorinsky model (left) and dynamic model (right)
Mass fraction plot, using 240 micron grid
Preliminary Simulation Results:
Mixing Only
Comparison between 240 micron grid (left) and 120 micron grid (right)
with dynamic model, mass fraction plot
Future Work
•
Improve code capability
–
Add missing physics
–
Add Chemistry
•
Validation Study (comparison with existing
experiments, such as HyShot II ground
experiments, and Stanford Mungal jet
-
in
-
crossflow experiments)
•
UQ/QMU analysis
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