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Summary form only given. Plasma assistance is a promising way for combustion improvement, especially for NOx reduction by burning leaner premixed hydrocarbons or for flame stabilization under unfavorable conditions (supersonic combustion or, small volume combustion where the chemical time is close to the fuel residence time). Thus, we conceived a combustion test bench where we could study the effect of a coaxial dielectric barrier discharge on a lifted non-premixed methane flame. For this study, we are especially interested in the effect of the discharge on the detachment height of the flame up to blow-out. There, we could achieve the anchoring of the flame (detachment height = 5-10 mm against 50-60 mm without plasma) on a plasma channel going out from the burner exit. Electrical investigations demonstrated that only 1 W applied to the discharge at the nozzle of the burner was necessary to this anchoring. Coupling electrical and optical measurements revealed the pulsed nature of the light emission of the plasma while spectroscopic study of OH, CH and N2* exhibits a 10 mm overlap between the plasma and the flame. Finally, fast camera movie of the flame anchoring zone was also achieved using narrow band filters for the selection of OH, CH and N2

In the first part of this paper (which is a modified version of Sabel'nikov and Gorokhovski [1, 2]), the IEM/LMSE micro-mixing model is further developed to account for the entire range of mixing f...

Long-term goals of the Research Ramjet Program (RRP) led at Onera are to provide a better understanding of the reacting flows inside r amjet combustion chambers and develop a predictive numerical tool, capable of characterizin g the performances of such combustors. A part of this program focuses on the Lean-Blow Out (LBO) phenomenon and aims at improving the understanding of the physical processes involved in the combustor blowoff and the calculations to predict this limit. The pre sent paper is mainly concerned with the computational component of that study, and specifically with the assessment of a Partially Stirred Reactor (PaSR) turbulent combustion model recently integrated in the Onera inhouse Computational Fluid Dynamic (CFD) code CEDRE. This combustion model, based on the Eddy Dissipation Concept (EDC) closure of Magnussen, is designed to describe the Turbulence ‐ Chemistry Interaction (TCI). Calculations have been performed to simulate a nominal operating point, and predict the LBO limit of the Research Ramjet combustion chamber. Significant results have been highlighted: 1) the PaSR combustion model yields results in good agreement with experimental data fo r the nominal operating point, and 2) the predicted LBO limit using the PaSR closure is fully satisfactory compared to the measurements.

The paper presents the results of the ducted combustion test program on the supersonic mixing and combustion enhancement in scramjet combustor using aerated by gas (hydrogen or air) liquid kerosene (effervescent) jets injected through elliptic nozzles from tube-micropylons and fin-pylons. Kerosene jets were injected into two-dimensional diverging-area supersonic combustor in two ways: 1) through nozzles in tube-micropyl ons at an angle of 45 degrees relative to the mainstream air flow direction and 2) through the nozzles located at the base of fin-pylons. In the latter case co-flow injection was used. Tests were conducted at entrance Mach number M=2.5 and total temperature in the range Tt=1650-1800K. The tests results with using elliptic nozzles were compared to baseline results with circular nozzles. The axial static pressure distributions on the combustor walls and calculated pressure-area integrals showed that the effervescent kerosene sprays performed better for elliptic nozzles than for round nozzles at injection from tubemicropylons. Injection from fin-pylons did not show noticeable difference in combustion efficiency for elliptic and round nozzles.