As a fundamental study in the application to direct-injection spark-ignition engines or gas turbines, in which mixture stratification and partial quenching are of serious concerns, unsteady premixed methane/ air flames subjected to time-varying composition fluctuations are investigated computationally. The code OPUS employs an unsteady opposed-flow combustion configuration, including detailed c...

This paper describes the non-linear dynamics of premixed flames responding to harmonic velocity disturbances. It extends a prior computational study which determined the key parameters influencing the nonlinear flame characteristics. It was shown that the linear and nonlinear characteristics of the flame dynamics were controlled by the superposition of two sources of flame disturbances: those o...

0016-2361/$ see front matter 2011 Elsevier Ltd. A doi:10.1016/j.fuel.2011.10.035 ⇑ Corresponding author. Tel.: +1 9372558781. E-mail address: [email protected] (V.R. Katta). Computational fluid dynamics (CFDs)-based predictions are presented for nonpremixed and partially premixed flames burning vaporized n-heptane fuel. Three state-of-the-art chemical kinetics models are incorporated into a tim...

The article presents the data related to the flame acquisitions in a liquid-fuel gas turbine derived burner operating in non-premixed mode under three different equivalence fuel/air ratio, which corresponds to a richer, an intermediate, and an ultra-lean condition, near lean blowout (LBO). The data were collected with two high speed visualization systems which acquired in the visible (VIS) and ...

INTRODUCTION Partially premixed flames (PPFs) contain a rich premixed fuel–air mixture in a pocket or stream, and, for complete combustion to occur, they require the transport of oxidizer from an appropriately oxidizer–rich (or fuel–lean) mixture that is present in another pocket or stream. Partial oxidation reactions occur in fuel–rich portions of the mixture and any remaining unburned fuel an...

Cooktop burners are widely used nowadays. In cooktop burner design, nozzle efficiency and greenhouse gas(GHG) emissions mainly depend on heat transfer from the premixed flame to the impinging surface. This is a complicated issue depending on the individual and combined effects of various input combustion variables. Optimal operating conditions for sustainable burner design were rarely addressed...

Optical emission tomography of flames has recently been demonstrated as a practical experimental technique for determining the instantaneous position of a 3D flame surface. In this paper, optical emission tomography is applied to steady and forced, non-axisymmetric, premixed, laminar flames. An experimental set-up involving a single camera and a rotatable flame holder allows camera images from ...

TheG-function approach to premixed combustion problems is based on the flamelet concept. Thereby, the flame front is modeled as an embedded interface within the bulk. A level set function is used to describe the position of the flame front. To account for discontinuities in the velocity and the pressure fields across the interface, an eXtended Finite Element Method (XFEM) is applied. That is, t...