High Speed Mixing and Combustion
The AECFDL has a long history in conducting simulations of flow fields relevant to high-speed propulsion devices, such as scramjets, dual-mode scramjet / ramjets, rocket-based combined cycle (RBCC) engines, and turbine-based combined cycle (TBCC) engines. Simulations have been performed using both Reynolds-averaged Navier-Stokes (RANS) and Large-eddy simulation (LES) techniques. Initial work in this area began in the late 1990s with the development of implicit methods for solving the RANS equations governing reactive flows. RANS simulations of a 3D jet diffusion flame in a supersonic wind tunnel were followed by studies of thermal choking in a JAXA-designed scramjet, simulations of mode transition in NASA Glenn’s GTX RBCC engine, and simulations of the starting process of the HySHOT engine in the University of Queensland’s T-4 shock tunnel. The development of hybrid LES/RANS methods at NCSU from 2004 to 2006 spurred a new burst of activity, including fundamental studies of reactant mixing as well as large-eddy simulations of the Burrows-Kurkov reacting wall jet experiment. Recent activity has concentrated on large-eddy simulations of a scramjet combustor tested at DLR in the mid 1990s and various combustor designs tested at the University of Virginia’s Scramjet Combustion Facility as part of the National Center for Hypersonic Combined-Cycle Propulsion. Included in these efforts have been fundamental studies of turbulence / chemistry interactions in supersonic combustion, the development and testing of subgrid models for the effects of unresolved fluctuations on species production rates, the development of synthetic-eddy generation methods for initiating and sustaining wall turbulence, and recently, simulations of cavity-stabilized ethylene combustion.
Images
Centerplane temperature contours (instantaneous and averaged) for hydrogen combustion in U. Virginia’s ‘Configuration C’ scramjet at two different equivalence ratios
Left: centerplane water mass fraction contours for DLR combustor (top: uniform inflow; bottom: non-uniform inflow)
Right: hydrogen fuel jets forced by synthetic turbulence
CARS vs. LES/RANS: reactive scalars vs. mixture fraction at different locations downstream of fuel injector (U. Virginia ‘Configuration C’ scramjet)
Sonic injection of ethylene into a supersonic crossflow (top: LES/RANS; bottom: NO-PLIF)
Three-dimensional flame structure showing effects of flow confinement (LES/RANS simulation of Burrows / Kurkov reacting wall jet experiment)
Mole fraction predictions at combustor exit (LES/RANS simulation of Burrows / Kurkov reacting wall jet experiment)
References
Potturi, A. and Edwards, J.R. “Investigation of Subgrid Closure Models for Finite-Rate Scramjet Combustion” AIAA Paper 2013-2461, June, 2013.
Fulton, J.A., Edwards, J.R., and Hassan, H.A. “Large-Eddy / Reynolds-Averaged Navier-Stokes Simulations of Reactive Flow in a Dual-Mode Scramjet Combustor”, accepted for publication, Journal of Propulsion and Power, 2013
Potturi, A.S. and Edwards, J.R. “Investigation of Flow through a Model Scramjet using a Hybrid LES/RANS Method” in review, AIAA Journal, 2013
Fulton, J.A., Edwards, J.R., Hassan, H.A., McDaniel, J., Goyne, C., Rockwell, R, “Continued Hybrid LES/RANS Simulation of a Hypersonic Dual Mode Combustor” AIAA Paper 2013-0117, January, 2013
Zilberter, I.A. and Edwards, J.R. “LES/RANS Simulations of Turbulent Mixing in Gas Plumes” AIAA Paper 2012-3925, July, 2012.
Edwards, J.R., Potturi, A., and Fulton, J.A. “Large-Eddy / Reynolds-Averaged Navier-Stokes Simulations of Scramjet Combustor Flow Fields” AIAA Paper 2012-4262, , July, 2012.
Fulton, J.A., Edwards, J.R., Hassan, H.A., Rockwell, R., Goyne, C, McDaniel, J., Smith, C., Cutler, A., Johansen, C., Danehy, P., and Kouchi, T. “Large-Eddy / Reynolds-Averaged Navier-Stokes Simulation of a Dual-Mode Scramjet Combustor,” January, 2012.
Potturi, A. and Edwards, J.R. “LES/RANS Simulation of a Supersonic Combustion Experiment” AIAA Paper 2012-0611, , January, 2012.
Edwards, J.R., Boles, J.A., and Baurle, R.A. “Large-Eddy / Reynolds-Averaged Navier-Stokes Simulation of a Supersonic Reacting Wall Jet” Combustion & Flame, Vol. 159, No. 3, 2012, pp. 1127-1138.
Zilberter, I.A. and Edwards, J.R. “LES/RANS Simulations of High-Speed Mixing Processes” AIAA Paper 2011-3423, June. 2011.
Boles, J.A., Edwards, J.R., and Choi, J.-I. “Large-Eddy / Reynolds-Averaged Navier-Stokes Simulations of Sonic Injection into Mach 2 Crossflow”. AIAA Journal. Vol. 48, No. 7, 2010, pp. 1444-1456.
Star, J.B., Edwards, J.R., Smart, M.K, and Baurle, R.A. “Investigation of Scramjet Flowpath Instability in a Shock Tunnel,” AIAA Paper 2006-3040, June, 2006.
Bond, R.B. and Edwards, J.R. “Computational Analysis of an Independent Ramjet Stream in a Combined Cycle Engine” AIAA Journal, Vol. 42, No. 11, 2004, pp. 2276-2284
Roy, C.J. and Edwards, J.R. “Numerical Simulation of a Three-Dimensional Flame / Shock Wave Interaction,” AIAA Journal, Vol. 38, No. 5, 2000, pp. 745-760.