Similarity solutions in buoyancy-controlled turbulent diffusion flame modeling (turbulent buoyant diffusion flame modeling)

✍ Scribed by M.A. Pivovarov; H. Zhang; D.E. Ramaker; P.A. Tatem; F.W. Williams

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 838 KB
• Volume: 92
• Category: Article
• ISSN: 0010-2180
• DOI: 10.1016/0010-2180(93)90042-2

✦ Synopsis

This work considers the applicability of different versions of the k-e hypothesis of turbulence for flame modeling. Utilizing similarity solutions, we find that the k-e hypothesis gives a finite radius for a weak axysimmetric plume above the heat source. The radius of this plume is defined as an eigenvalue of the boundary value problem with unknown boundary. Solving this problem with an adjusted set of parameters from the standard version of the k-e hypothesis gives excellent agreement with experimental data for center line and radial profiles of the mean and turbulent quantities, and also for the radius of the plume and entrainment level. In contrast, the standard set of parameters, widely utilized in flame modeling, gives inaccurate predictions. Specifically, this set of parameters yields underestimates of the radius of the plume and the entrainment level. Since this same trend has been extensively observed in flame modeling, we conclude that the standard set of parameters for the k-e hypothesis is inadequate, and that this is the main reason for the shortcomings of previous numerical models.