A multivariate quadrature based moment method for LES based modeling of supersonic combustion

Donde, Pratik; Koo, Heeseok; Raman, Venkat

doi:10.1016/j.jcp.2012.04.031

Cited by 34 publications

(18 citation statements)

References 52 publications

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“…The simulations were performed using the in-house compressible flow solver UTComp, which has been extensively verified and validated [23,[42][43][44][45]. The solver uses a finite difference fifth-order weighted essentially non-oscillatory Lax-Friedrichs (WENO LLF) scheme with characteristics reconstruction to compute the fluxes [46,47].…”

Section: Flow Configuration and Numerical Detailsmentioning

confidence: 99%

Numerical Investigation of Shock-Train Response to Inflow Boundary-Layer Variations

et al. 2017

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A dataset of normal shock trains in a rectangular cross-section channel has been created from direct numerical simulations in an effort to quantify the impact of inflow confinement ratio on the shock-train structure. To this end, the inlet boundary-layer momentum thickness was varied while the bulk inflow and outflow conditions remained constant. The simulations show that the shock train is displaced upstream as the inflow confinement ratio increases. Also, an increase in boundary-layer momentum thickness results in a reduction of the normal-like portion of the lambda-shock structures in the channel core. This leads to more numerous but weaker bifurcating shocks as well as an increase of the shock-train length. When the inflow boundary-layer thickness is varied temporally, the complex shocktrain response depends on the excitation frequency. A resonant frequency is observed when different components of the shock train exhibit the highest amplification in terms of pressure jumps. Further, the domain upstream of the leading shock acts as a low-pass filter, which has the end result of limiting the axial shock-train motion. Nevertheless, even a small oscillation in boundary-layer momentum thickness of 0.45 mm (0.6% of the channel height) is seen to increase the shock-train length by two orders of magnitude (4 cm).

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Section: Flow Configuration and Numerical Detailsmentioning

confidence: 99%

Numerical Investigation of Shock-Train Response to Inflow Boundary-Layer Variations

et al. 2017

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“…The DNS calculation was performed using an in-house compressible flow solver, UTComp 31,32,33 . The solver is based on a fifth-order WENO scheme 34 to compute the nonlinear terms in the momentum and t E equations.…”

Section: B Dns Configuration and Numerical Detailsmentioning

confidence: 99%

Vibrational Non-equilibrium Effects in Supersonic Jet Mixing

Reising

Utsav

Voelkel

et al. 2014

52nd Aerospace Sciences Meeting

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A joint experimental and computational study is being conducted to investigate the effects of vibrational non-equilibrium on supersonic combustion, although the focus of this paper is on mixing between a supersonic jet and a subsonic coflow. A new facility has been constructed that consists of a Mach 1.5 turbulent jet issuing into an electrically heated coflow. In the preliminary experiments reported here, air is used in both the jet and the coflow. The degree of non-equilibrium in the jet shear layers is quantified by using high-spectral resolution timeaverage spontaneous Raman scattering. The Raman scattering is complemented with planar temperature imaging using Rayleigh scattering. Much of the current work is focused on the extent to which vibrational non-equilibrium can be assessed by using time-averaged Raman scattering in a turbulent flow with large-scale temperature fluctuations. The experimental work is supported by direct numerical simulation of related jet flows. Preliminary DNS of turbulent jets in coflow with imposed vibrational non-equilibrium shows that vibrational relaxation effects have a first-order effect on the jet temperature field and mixing physics. Nomenclature= specific heat at constant volume of species, α = vibrational energy = projected pixel dimension in physical plane = convective Mach number = incident laser power = Rayleigh scattered power = partition function − = translational-vibrational energy exchange , = reference temperature by which is defined for species, α = rotational temperature = translational temperature = vibrational temperature = passive scalar concentration = visual shear layer thickness  = characteristic vibrational temperature of an oscillator  = reduced mass of colliding pair 2  = vibrational relaxation timescale Ø = mass fraction of species, α = mixture fraction of species, α = collection solid angle ( ) = Rayleigh scattering cross-section

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“…Such approaches require the closure for the filtered (or ensemble averaged) chemical source term in the species transport equations. This can be achieved, for example, with simpler but low-accuracy models such as the direct use of the Arrhenius law with the mean quantities [6,7], which neglects closure, the Eddy Dissipation Concept model [8], or with closure based on assumed [9,10] or transported [11][12][13][14] probability density functions (PDF). Also, the Linear Eddy model (LEM) [15,16] has been applied for this case.…”

Section: Introductionmentioning

confidence: 99%

An efficient flamelet-based combustion model for compressible flows

Saghafian

Terrapon

Pitsch

2015

Combustion and Flame

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A combustion model based on a flamelet/progress variable approach for highspeed flows is introduced. In the proposed formulation, the temperature is computed from the transported total energy and tabulated species mass fractions. Only three additional scalar equations need to be solved for the combustion model. Additionally, a flamelet library is used that is computed in a pre-processing step. This approach is very efficient and allows for the use of complex chemical mechanisms. An approximation is also introduced to eliminate costly iterative steps during the temperature calculation. To better account for compressibility effects, the chemical source term of the progress variable is rescaled with the density and temperature. The compressibility corrections are analyzed in an a priori study. The model is also tested in both Reynolds-averaged Navier-Stokes (RANS) and large-eddy simulation (LES) computations of a hydrogen jet in a supersonic transverse flow.Comparison with experimental measurements shows good agreement, partic- * ularly for the LES case. It is found that the disagreement between RANS results and experimental data is mostly due to the mixing model deficiencies and the presumed probability density functions used in the RANS formulation. A sensitivity study of the proposed model shows the importance of the compressibility corrections especially for the source term of the progress variable.

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A multivariate quadrature based moment method for LES based modeling of supersonic combustion

Cited by 34 publications

References 52 publications

Numerical Investigation of Shock-Train Response to Inflow Boundary-Layer Variations

Numerical Investigation of Shock-Train Response to Inflow Boundary-Layer Variations

Vibrational Non-equilibrium Effects in Supersonic Jet Mixing

An efficient flamelet-based combustion model for compressible flows

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