Numerical simulations of reacting and non-reacting flows within a scramjet combustor configuration experimentally mapped at the University of Virginia's Scramjet Combustion Facility (operating with Configuration "A") are described in this paper. Reynolds-Averaged Navier-Stokes (RANS) and hybrid Large Eddy Simulation / Reynolds-Averaged Navier-Stokes (LES / RANS) methods are utilized, with the intent of comparing essentially 'blind' predictions with results from non-intrusive flow-field measurement methods including coherent anti-Stokes Raman spectroscopy (CARS), hydroxyl radical planar laser-induced fluorescence (OH-PLIF), stereoscopic particle image velocimetry (SPIV), wavelength modulation spectroscopy (WMS), and focusing Schlieren. NC State's REACTMB solver was used both for RANS and LES / RANS, along with a 9-species, 19reaction H 2-air kinetics mechanism by Jachimowski. Inviscid fluxes were evaluated using Edwards' LDFSS flux-splitting scheme, and the Menter BSL turbulence model was utilized in both full-domain RANS simulations and as the unsteady RANS portion of the LES / RANS closure. Simulations were executed and compared with experiment at two equivalence ratios, Ф = 0.17 and Ф = 0.34. Results show that the Ф = 0.17 flame is hotter near the injector while the Ф = 0.34 flame is displaced further downstream in the combustor, though it is still anchored to the injector. Reactant mixing was predicted to be much better at the lower equivalence ratio. The LES / RANS model appears to predict lower overall heat release compared to RANS (at least for Ф = 0.17), and its capability to capture the direct effects of larger turbulent eddies leads to much better predictions of reactant mixing and combustion in the flame stabilization region downstream of the fuel injector. Numerical results from the LES/RANS model also show very good agreement with OH-PLIF and SPIV measurements. An un-damped long-wave oscillation of the pre-combustion shock train, which caused convergence problems in some RANS simulations, was also captured in LES / RANS simulations, which were able to accommodate its effects accurately.

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The Einstein-Rosen-Podolsky (EPR) paradox gives an argument for the incompleteness of quantum mechanics based on the premise of local realism. The general viewpoint is that the argument is compromised, because local realism is falsifiable by Bell or Greenberger-Horne-Zeilinger (GHZ) experiments. In this paper, we challenge this conclusion, by presenting alternative versions of the EPR paradox based on premises not falsifiable by the GHZ and Bell predictions. First, we explain how the Bohm-EPR and GHZ paradoxes can be demonstrated using macroscopic spins Ŝθ formed from qubits realised as two macroscopically distinct states. This establishes an "all or nothing" incompatibility between quantum mechanics and macroscopic realism (MR). However, we note different definitions of MR. For a system in a superposition of two macroscopically distinct eigenstates of Ŝθ , MR posits the system to have a definite value for the outcome of Ŝθ . Deterministic macroscopic realism (dMR) posits MR regardless of whether the physical interaction U θ determining the measurement setting θ has actually occurred. In contrast, the weaker assumption, weak macroscopic realism (wMR), posits MR for the system prepared after U θ . We show that the GHZ paradox negates dMR but is consistent with wMR. Yet, we show that a Bohm-EPR paradox for the incompleteness of quantum mechanics arises, based on either form of MR. Since wMR is not falsified, this raises the question of how to interpret the EPR paradox. We revisit the original EPR paradox and find a similar result:The EPR argument can be based on a contextual version of local realism (wLR) alluded to by Bohr, which is not falsifiable by Bell or GHZ experiments. The premises wLR and wMR posit realism and no-disturbance for systems prepared with respect to a pointer basis (after U θ ), leading to further predictions giving consistency with quantum mechanics.

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The development of a reactive flow solver suitable for large-scale simulations of high-speed engine component flow fields is described in this paper. The intent is to mature an existing flow solver, North Carolina State University's REACTMB, into a production-level tool suitable for test and evaluation (T&E) activities. The computational framework is based on the combined use of Reynolds-averaged Navier-Stokes (RANS) methods and large-eddy simulation (LES) strategies, with the former used to examine system-level effects and the latter used for detailed component studies.Specific modifications that extend the capabilities of REACTMB (bleed modeling, eddy-dissipation combustion modeling) are described, as are methods for coupling flow solutions with established 1D system performance tools.