Modelling flame turbulence interaction in RANS simulation of premixed turbulent combustion

Abstract

Flame turbulence interaction ( ∆ c ) is an important term for modelling scalar dissipation ( ε c ) in premixed turbulent combustion. In order to obtain an accurate representation of the flame turbulence interaction phenomenon, an evolution equation for ∆ c has recently been proposed. This equation gives a detailed insight into the flame turbulence interaction phenomenon and provides an alternative approach to model the important physics represented by ∆ c . In this paper the ∆ c evolution equation is used to model a premixed propane-air flame stabilised in a turbulent mixing layer. The simulations are carried out in the context of a Reynolds Averaged Navier Stokes (RANS) framework and the results are compared with the experiments and also with the Large Eddy Simulation (LES). It is found that the modelling strategy involving the ∆ c evolution equation gives good approximations for the mean velocities and flame locations in the mixing layer stabilised flame when compared with other modelling strategies.

Effects of turbulence intensity and length scale on the flame location of premixed turbulent combustion in a diffuser combustor

“…The k-ԑ model is also used to involve the turbulent effect within the Reynolds-averaged Navier-Stokes (RANS) framework (Tangermann et al 2010, Ahmed and Prosser 2016, and Huang et al 2016, which is a main approach used to simulate the premixed combustion and turbulence problem. Density varies during combustion.…”

“…Therefore, the interaction between premixed flame and turbulence has become an important research area and is considered a main problem in combustion analysis (Pope 1978, Peters 2004, and Poinsot & Veynante 2005. Many researchers, such as (Marble and Broadwell 1977, Borghi 1989, Veynante and Vervisch 2002, and Ahmed & Prosser 2016, studied the influence of turbulence on a premixed turbulent flame and proposed many models for modeling premixed turbulent combustion. Most of these studies dealt with solving the source term in the species equation.…”

A Posteriori Assessment of Algebraic Scalar Dissipation Models for RANS Simulation of Premixed Turbulent Combustion

“…This approximation leads to simple closures for a number of turbulence related terms. Several modelling approaches have been developed by using the flamelet assumption and PPDF framework and include; laminar flamelets [10,28,41]; the G−equation [32]; scalar dissipation rate and flame turbulence interaction based approaches [2,3,12,40] and flame surface density models [18,60].…”

“…Several scalar dissipation rate models of varying complexity have been proposed, and range from a complete transport equation to simple algebraic models. The algebraic scalar dissipation rate based modelling approaches have been used in previous studies by Dong et al [25], Ahmed and Prosser [2] and Kolla and Swaminathan [41] via the Reynolds Averaged Navier Stokes (RANS) framework and by Langella et al [45] via Large Eddy Simulation (LES). In a recent study by Ahmed and Prosser [2] the leading order scalar dissipation transport equation has been used to close the reaction rate and the performance of the algebraic scalar dissipation model proposed by Kolla et al [40] is also compared with the predictions from the leading order scalar dissipation transport equation.…”

“…The algebraic scalar dissipation rate based modelling approaches have been used in previous studies by Dong et al [25], Ahmed and Prosser [2] and Kolla and Swaminathan [41] via the Reynolds Averaged Navier Stokes (RANS) framework and by Langella et al [45] via Large Eddy Simulation (LES). In a recent study by Ahmed and Prosser [2] the leading order scalar dissipation transport equation has been used to close the reaction rate and the performance of the algebraic scalar dissipation model proposed by Kolla et al [40] is also compared with the predictions from the leading order scalar dissipation transport equation. Furthermore Ahmed and Prosser [2] have also compared the results of the scalar dissipation rate based modelling approach with the flame surface density based modelling approach and concluded that the scalar dissipation rate based modelling approach leads to more physically plausible results.…”