Print Email Facebook Twitter Joint Scalar versus Joint Velocity-Scalar PDF Simulations of Bluff-Body Stabilized Flames with REDIM Title Joint Scalar versus Joint Velocity-Scalar PDF Simulations of Bluff-Body Stabilized Flames with REDIM Author Merci, B. Naud, B. Roekaerts, D. Maas, U. Faculty Applied Sciences Department Multi-Scale Physics Date 2008-07-03 Abstract Two transported PDF strategies, joint velocity-scalar PDF (JVSPDF) and joint scalar PDF (JSPDF), are investigated for bluff-body stabilized jet-type turbulent diffusion flames with a variable degree of turbulence–chemistry interaction. Chemistry is modeled by means of the novel reaction-diffusion manifold (REDIM) technique. A detailed chemistry mechanism is reduced, including diffusion effects, with N 2 and CO 2 mass fractions as reduced coordinates. The second-moment closure RANS turbulence model and the modified Curl’s micro-mixing model are not varied. Radiative heat loss effects are ignored. The results for mean velocity and velocity fluctuations in physical space are very similar for both PDF methods. They agree well with experimental data up to the neck zone. Each of the two PDF approaches implies a different closure for the velocity-scalar correlation. This leads to differences in the radial profiles in physical space of mean scalars and mixture fraction variance, due to different scalar flux modeling. Differences are visible in mean mixture fraction and mean temperature, as well as in mixture fraction variance. In principle, the JVSPDF simulations can be closer to physical reality, as a differential model is implied for the scalar fluxes, whereas the gradient diffusion hypothesis is implied in JSPDF simulations. Yet, in JSPDF simulations, turbulent diffusion can be tuned by means of the turbulent Schmidt number. In the neck zone, where the turbulent flow field results deteriorate, the joint scalar PDF results are in somewhat better agreement with experimental data, for the test cases considered. In composition space, where results are reported as scatter plots, differences between the two PDF strategies are small in the calculations at hand, with a little more local extinction in the joint scalar PDF results. Subject CFDTransported PDFREDIMBluff body stablised flames To reference this document use: http://resolver.tudelft.nl/uuid:0f454400-03d3-41d4-a6bb-025656d75eab DOI https://doi.org/10.1007/s10494-008-9162-2 Publisher Springer ISSN 1573-1987 Source Flow, Turbulence and Combustion, 82 (2), 2009 Part of collection Institutional Repository Document type journal article Rights (c) 2008 Merci, B.; Naud, B.; Roekaerts, D.; Maas, U. Files PDF merci-2009.pdf 876.25 KB Close viewer /islandora/object/uuid:0f454400-03d3-41d4-a6bb-025656d75eab/datastream/OBJ/view