The Lagrangian Flamelet Model is formulated as a combustion model for large-eddy simulations of turbulent jet diffusion flames. The model is applied in a large-eddy simulation of a piloted partially premixed methane/air diffusion flame ~Sandia flame D!. The results of the simulation are compared to experimental data of the mean and RMS of the axial velocity and the mixture fraction and the unco...

We present a three-dimensional, time-dependent simulation of a laboratory-scale rod-stabilized premixed turbulent V-flame. The experimental parameters correspond to a turbulent Reynolds number, Re(t) = 40, and to a Damköhler number, D(a) = 6. The simulations are performed using an adaptive time-dependent low-Mach-number model with detailed chemical kinetics and a mixture model for differential ...

Fully developed stationary premixed flames are obtained by DNS in an incoming homogeneous isotropic turbulent flow. Analysis based on the Favre-averaged transport equation of turbulent kinetic energy shows that pressure gradient term and pressure work term increase turbulent kinetic energy in the flame region, and these terms produce anisotropic turbulence. The counter-gradient diffusion domina...

To reveal the inner mechanism of gas explosion dynamic behavior affected by gas equivalent concentration, a high speed Schlieren image system and flow field measurement technology was applied to record the gas explosion flame propagation and flame structure transition. The results show that a flame front structure transition occurs, followed by a flame accelerating propagation process. The lami...

Nonlinear model equation for weakly turbulent premixed flames with realistic fuel expansion is proposed. The equation describes both the hydrodynamic flame instability and flame response to external turbulence in the regime of flamelets. On the basis of the proposed equation the velocity of turbulent flames is investigated for the cases of both weak and relatively strong turbulence. Comparison ...

The objective of this work was to investigate the influence of preferential diffusion on flame structure and propagation of lean-premixed hydrogen-carbon monoxide syngas-air flame at elevated pressure using direct numerical simulation (DNS) and detailed chemistry. The physical problem investigated is lean-premixed H2/CO outwardly propagating turbulent spherical flame at constant pressure of 4ba...

A water mist jet for a steam generator of direct contact with a diffusion flame is numerically analyzed in this paper. Numerical simulation is conducted for an 8 Lug-Bolt array in a confined system. The diffusion flame is modelled in the Eulerian Eulerian multiphase approach where the reaction species are oxygen which is injected by a 16.9 mm central nozzle, methane by four peripheral 5.86 mm n...

The dynamics of soot formation in turbulent ethylene–air nonpremixed counterflow flames is studied using direct numerical simulation (DNS) with a semi-empirical soot model and the discrete ordinate method (DOM) as a radiation solver. Transient characteristics of soot behavior are studies by a model problem of flame interaction with turbulence inflow at various intensities. The interaction betwe...

Flame instabilities play a dominant role in accelerating the burning front to a large fraction of the speed of sound in a Type Ia supernova. We present a threedimensional numerical simulation of a Rayleigh-Taylor unstable carbon flame, following its evolution through the transition to turbulence. A low Mach number hydrodynamics method is used, freeing us from the harsh timestep restrictions imp...

A modified version of the linear eddy model (LEM) for subgrid combustion is developed and used for studying the properties of turbulent premixed flames in the core region of Couette flow. The handling of the burning (diffusion/reaction) and specie transport, in this new approach, is fully deterministic. The model is, therefore, found to predict the correct laminar flame speed in the limit of ze...