AMS 599 Special Topics in Applied Mathematics


22 Φεβ 2014 (πριν από 3 χρόνια και 1 μήνα)

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AMS 599

Special Topics in Applied

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

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

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

Outline of Presentation

Problem specification and dimensional

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

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

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

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

Preliminary Simulation Results:

Mixing Only

3D simulation. 67% H

mass concentration

isosurface plot compared to experimental

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

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


mass fraction contour plotted at the midline plane

Preliminary Simulation Results:

Mixing Only

wise velocity

contour plotted at the midline plane

Preliminary Simulation Results:

Mixing Only


mass fraction contour plotted at x/d=2.4

Preliminary Simulation Results:

Mixing Only

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
crossflow experiments)

UQ/QMU analysis