Experimental characterization and numerical simulation of a sooting lifted turbulent jet diffusion flame

TitleExperimental characterization and numerical simulation of a sooting lifted turbulent jet diffusion flame
Publication TypeJournal Article
Year of Publication2013
AuthorsKöhler, M, Geigle, KP, Blacha, T, Gerlinger, P, Meier, W
Journal TitleCombustion and Flame

A sooting C 2H4/air jet diffusion flame was investigated experimentally by laser measuring techniques andthe results are compared to CFD calculations. The target flame (C 2H4 10.4 g/min, bulk exit velocity 44 m/s,RE = 10,000) exhibits well-defined boundary conditions and presents a good test case for model validation.Flow velocity, temperature and soot volume fraction in this flame has been measured previously.In this paper, further experimental results from Raman scattering and laser-induced fluorescence (LIF)measurements are presented to expand the validation data base. Raman scattering is used to measurethe fuel/air mixing prior to combustion, while LIF of PAHs monitors the soot precursor region and successiveplanar OH–LIF serves to map the flame front position and its statistics.Furthermore, a numerical simulation of this flame was performed based on the DLR in-house codeTHETA. Within the scope of the test case presented here, the code combines a relatively detailed descriptionof the gas phase kinetics coupled with a detailed yet computation-efficient soot model, suitable forCFD applications. This model has been designed to predict soot for a variety of fuels and flames with goodaccuracy at relatively low computational costs. Universal model parameters are applied, which requiresno tuning for the dependence of test case or fuel. The experimental and numerical results are comparedand discussed with special emphasis on the pre-flame region of the jet and up to the downstream positionwhere significant soot concentrations are present. Validation shows the general applicability of theCFD code with implemented soot model to rather complex systems like the target sooting turbulent jetflame. Identified discrepancies are analyzed and can be explained, while opening up the field for futureoptimization of parts of the CFD code.