Three-dimensional Linear Eddy Modeling of a Turbulent Lifted Hydrogen Jet Flame in a Vitiated Co-flow

• Published in: Flow, turbulence and combustion Vol. 101; no. 4; pp. 993 - 1007
• Main Authors: Grøvdal, Fredrik, Sannan, Sigurd, Chen, Jyh-Yuan, Kerstein, Alan R., Løvås, Terese
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01-12-2018; Springer Nature B.V
• Subjects: Aerodynamics; Automotive Engineering; Computational fluid dynamics; Computer simulation; Engineering; Engineering Fluid Dynamics; Engineering Thermodynamics; Flame structure; Fluid- and Aerodynamics; Heat and Mass Transfer; Jet flow; Modelling; Post-processing; Three dimensional models; Vortices; Subgrid scalar closure; Linear eddy model; Turbulent mixing; Turbulent reactive flows
• ISSN: 1386-6184; 1573-1987
• DOI: 10.1007/s10494-018-9963-x

A new methodology for modeling and simulation of reactive flows is reported in which a 3D formulation of the Linear Eddy Model (LEM3D) is used as a post-processing tool for an initial RANS simulation. In this hybrid approach, LEM3D complements RANS with unsteadiness and small-scale resolution in a computationally efficient manner. To demonstrate the RANS-LEM3D model, the hybrid model is applied to a lifted turbulent N
2
-diluted hydrogen jet flame in a vitiated co-flow of hot products from lean H
2
/air combustion. In the present modeling approach, mean-flow information from RANS provides model input to LEM3D, which returns the scalar statistics needed for more accurate mixing and reaction calculations. Flame lift-off heights and flame structure are investigated in detail, along with other characteristics not available from RANS alone, such as the instantaneous and detailed species profiles and small-scale mixing.