We describe flame propagation in a channel subject to a Poiseuille flow, within the thermo-diffusive approximation and an adiabatic context. The two-dimensional flame fronts addressed may be either assisted or opposed by the flow. The problem is characterized by two parameters, the intensity of the flow u0 and the spatial scale e. The total burning rate and the propagation speed are determined ...

A spectral formalism has been developed for the “non-intrusive” analysis of parametric uncertainty in reacting-flow systems. In comparison to conventional Monte Carlo analysis, this method quantifies the extent, dependence, and propagation of uncertainty through the model system and allows the correlation of uncertainties in specific parameters to the resulting uncertainty in detailed flame str...

We derive analytical expressions for the burning rate of a flame propagating in a prescribed steady parallel flow whose scale is much smaller than the laminar flame thickness. In this specific context, the asymptotic results can be viewed as an analytical test of Damköhler’s hypothesis relating to the influence of the small scales in the flow on the flame; the increase in the effective diffusio...

The development and propagation of detonations is examined in the presence of diffusive processes. The difference between the inviscid and viscous models is quantitatively evaluated for one-dimensional propagating detonations. First, an investigation of viscous effects is performed on one-dimensional pulsating unsupported Chapman-Jouguet detonations using a simplified one step kinetics model fo...

Dynamic models for large eddy simulation of the G-equation of turbulent premixed combustion are proposed and tested in forced homogeneous isotropic turbulence. The basic idea is to represent the ‘‘filtered propagation term’’ as ‘‘propagation of the filtered front at higher speed,’’ where the enhanced filtered-front speed is modeled. The validity of the linear relation between the turbulent flam...

A transport equation residual model incorporating a Damkohler criterion has been developed and implemented in the ERC KIVA-3V code for Gasoline Direct Injection (GDI) engine simulations for better predictions of flame propagation. In the transport equation residual model a fictitious species concept is introduced to account for the residual gases in the cylinder, which have a great effect on th...

A theoretical–numerical analysis based on the second law of thermodynamics is used to examine the propagation of laminar H2-enriched CH4–air flames. The analysis is based on computing the various entropy generation terms in a transient reacting flow field. A comprehensive, time-dependent computational model, which employs a detailed description of chemistry and transport, is used to simulate th...