1. Develop high-fidelity modeling and efficient simulation techniques for supercritical combustion
High-Fidelity Modeling and Simulation of Supercritical Combustion AFOSR Grant No. FA Vigor Yang, Suresh Menon, and Joseph C. Oefelein
2D DNS LOX/CH4 mixing layer: cold flow (left) and combustion (right)
turbulent-chemistry interaction
SGS motions
real-fluid property evaluation
Flamelet-progress variable vs. correlated dynamic chemistry model
Computational
time
SGS modeling
FPV
FRC
Acceleration of real-fluid property evaluation
Time Z
Therm.
Trans.
Others
Baseline
2.97 ms
28.8%
19.2%
5.5%
46.5%
CDE
1.77 ms
10.3%
9.7%
2.3%
77.7%
Tabulation
1.45 ms
0.1%
6.9%
2.8%
90.2%
reduction in error in filtered density term
𝜺 𝝓 = 𝝓(𝑸 − 𝝓 𝑸 𝝓(𝑸
Baseline: brutal force evaluation; CDE: correlated dynamic evaluation
Tabulation: pre-calculated and stored in a library

2. Vapor-liquid-equilibrium (VLE) framework for super-critical mixing and combustion in LES modeling
3-injector sector LRE: LOX-GCH4
𝑻 𝑳𝒐𝒙 =𝟏𝟏𝟎 𝐊, 𝑻 𝑪𝑯𝟒 =𝟐𝟔𝟎 𝐊
P = 130 bar (supercritical)
Resolving near-injection region is difficult due to large density gradients created by non-ideal thermodynamics, and a multi- phase state, not represented by a single EoS. Vapor-liquid Equilibrium is being included into LES and subgrid models
Phase fraction 𝜷∈[𝟎,𝟏] identified multi-phase conditions at the interface of the two species. Without accounting for this thermodynamics, unphysical states are obtained
3D TML of 𝑵 𝟐 / 𝑪 𝟔 𝑯 𝟏𝟒 LES-VLE test case
𝑻 𝑵𝟐 =𝟐𝟗𝟖 𝐊, 𝑻 𝑪𝟔𝑯𝟏𝟒 =𝟒𝟕𝟎−𝟔𝟎𝟎 𝐊
P = 50 bar
liquid
Temperature (left) and Q-criterion with O2 mass fraction (right)
gas
15-injector test model for VLE
GOX-GCH4 (above) and LOX-GCH4 (planned)

3. Progression of DNS/LES benchmarks performed using RAPTOR code
DNS of liquid n-decane-air
jet-in-cross-flow:
Re = 100,000 (jet), ,000 (cross-flow)
P = 40 bar (supercritical)
DNS of 3D mixing layer designed to emulate an array of methane/LOX streams at conditions relevant to LRE’s in progress on Oak Ridge Summit platform
Mixture fraction isosurface (high)
Mixture fraction isosurface (low)
Vorticity (reveals structure)
Scalar dissipation
Hybrid-DNS/LES of methane-LOX shear-coaxial and swirl-coaxial injection processes at conditions that match the geometry and operating conditions of the AFRL combustion stability experiment (Wegener, Leyva, Forliti, and Talley, AIAA Paper ).