Large-Eddy Simulation of oxygen/methane flames under transcritical conditions

Schmitt, Thomas; Méry, Yoann; Boileau, Matthieu; Candel, Sébastien

doi:10.1016/j.proci.2010.07.036

Cited by 103 publications

(70 citation statements)

References 41 publications

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“…In addition to the backflow region that forms close to the chamber wall between the flame and the face plate, a secondary recirculation can be observed downstream of the reaction zone. This was also observed in the LES result of Schmitt et al [20]. Due to the interaction with the chamber wall in the rear part of the flame, the flow of hot combustion products is redirected towards the chamber axis where is flows back towards the flame.…”

Section: General Flame Featuressupporting

confidence: 68%

“…An additional subject that needs to be addressed is the choice of an appropriate combustion model for this configuration. In previous LES studies of this test case, Guézennec et al [19] employed a reduced reaction mechanism accounting for finite-rate chemistry, while Schmitt et al [20] made the assumption of infinitely fast chemistry. This assumption was also made by Cutrone et al [21] as well as by Kim et al [22] who simulated the test case of Singla et al [18] using a Reynolds-averaged Navier-Stokes (RANS) flamelet model.…”

Section: Introductionmentioning

confidence: 99%

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A flamelet model for transcritical LOx/GCH₄flames

Müller

Pfitzner

2017

J. Phys.: Conf. Ser.

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Abstract. This work presents a numerical framework to efficiently simulate methane combustion at supercritical pressures. A LES flamelet approach is adapted to account for real-gas thermodynamics effects which are a prominent feature of flames at near-critical injection conditions. The thermodynamics model is based on the Peng-Robinson equation of state (PR-EoS) in conjunction with a novel volume-translation method to correct deficiencies in the transcritical regime. The resulting formulation is more accurate than standard cubic EoSs without deteriorating their good computational performance. To consistently account for pressure and strain fluctuations in the flamelet model, an additional enthalpy equation is solved along with the transport equations for mixture fraction and mixture fraction variance. The method is validated against available experimental data for a laboratory scale LOx/GCH 4 flame at conditions that resemble those in liquid-propellant rocket engines. The LES result is in good agreement with the measured OH * radiation. IntroductionTodays main stage liquid-propellant rocket engines (LRE) typically operate at supercritical pressures, i.e., at chamber pressures that exceed the critical pressure of the propellants, and at cryogenic injection temperatures. One or both of the propellants are thus injected at near-critical conditions and mixing, ignition and combustion are affected by non-ideal thermodynamic effects. In particular, the thermodynamic-and transport properties, e.g., density, enthalpy, viscosity, are highly non-linear functions of temperature and pressure. Moreover, the experiments of Mayer et al. [1,2] showed that the surface tension between liquid and vapor is diminished at sufficiently high pressures and mixing is characterized by continuous-phase diffusion rather than by two-phase spray atomization. In these diffusion mixing layers, the fluid properties change drastically and the density may vary by two orders of magnitude within a few micrometers.Such configurations pose a serious challenge for numerical as well as for experimental studies. At the same time, their investigation is important to better understand the involved processes and to develop tools that help in the design of LREs, but also of other high pressure combustion devices, such as novel Diesel motors or gas turbines. The topic received considerable attention in the last decade and several valuable experiments were carried out. Thorough overviews are given, for instance, by Oschwald et al. [5] focusing on the Mascotte testing facility. Along with the better understanding that has been generated by the experimental efforts, several groups developed models and numerical tools to perform simulations of near-critical mixing and combustion allowing for a detailed view on the flow. Among the first to conduct large-eddy simulations (LES) of supercritical injection was Oefelein and Yang [6] and later Zong et al. [7] as well as Oefelein [8]. These studies showed that the accurate treatment of thermodynamic non-idealities are ke...

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Section: General Flame Featuressupporting

confidence: 68%

Section: Introductionmentioning

confidence: 99%

A flamelet model for transcritical LOx/GCH₄flames

Müller

Pfitzner

2017

J. Phys.: Conf. Ser.

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“…combustion are generally validated by verifying that the flame expansion angle of the simulation reproduces the experimental observation [9][10][11].…”

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confidence: 86%

Correlation of optical emission and turbulent length scale in a coaxial jet diffusion flame

Matsuyama

2014

Combustion and Flame

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“…NSCBC boundary conditions are adapted to real-gas thermodynamics as well [75]. Chemical conversion is handled using the infinitely fast chemistry model (IFCM) derived in [65]. This model is modified to account for the following species: CH 4 , O 2 , CO 2 , H 2 O, CO and H 2 in order to properly calculate the burnt gas temperature.…”

Section: Brief Description Of the Les Solvermentioning

confidence: 99%

“…Efforts to model and simulate real-gas effects [47][48][49][50][51][52][53][54][55][56][57] in an unsteady transcritical combustion have allowed to examine flame structures and dynamics by making use of large eddy simulations (LES). LES of transcritical coaxial jets and flames [58][59][60][61][62][63][64][65] show that it is possible to obtain reasonable predictions of transcritical flames and that such simulations could be used to explore transcritical jets and flames behavior under acoustic forcing as demonstrated in [66][67][68][69].…”

Section: Introductionmentioning

confidence: 99%