This study has assessed the validity of the commercially available turbulent flame speed models within ANSYS Fluent as applied to hydrogen/methane/air combustion, with 5 different fuel compositions considered from 100% methane to 100% hydrogen. It was found that existing turbulent flame speed models were capable of producing accurate predictions up to 60% hydrogen with the Zimont model being th...

The effects of dimethyl ether (DME) addition on the high temperature ignition and burning properties of methane-air mixtures were studied experimentally and numerically. The results showed that for a homogeneous system, a small amount of DME addition to methane resulted in a significant reduction in the high temperature ignition delay. The ignition enhancement effect by DME addition was found t...

In this work, the effects of the electric fields on the flame propagation and combustion characteristics of lean premixed methane–air mixtures were experimentally investigated in a constant volume chamber. Results show that the flame front is remarkably stretched by the applied electric field, the stretched flame propagation velocity and the average flame propagation velocity are all accelerate...

Turbulent methane flames exhibit a change in Markstein number as the equivalence ratio changes. In this paper, we demonstrate how these changes in Markstein number are related to shifts in the chemistry and transport. We focus on the analysis of simulations of two-dimensional premixed turbulent methane flames at equivalence ratios φ=0.55 and φ=1.00 computed using the GRI-Mech 3.0 mechanism. The...

Recent advances in automation of systematically reduced mechanisms are reported here with the aim to accelerate the development process. A computer algorithm has been developed enabling fast generation and testing of reduced chemistry. This algorithm has been used to develop various reduced mechanisms of methane-air combustion for modelling of turbulent combustion. A 10-step reduced chemistry h...

The interaction of a premixed methane/air flame with a counter-rotating vortex pair is analyzed using a parallel low-Mach-number computational model that is based on a detailed C1C2 chemical mechanism. Attention is focused on the transient response of the heat release rate and the flame structure at the centerline of the vortex pair. Results are obtained for vortex pairs of different strengths ...

Turbulent-flame speeds in methane–air mixtures were measured in a Taylor–Couette apparatus with counter-rotating cylinders, used to generate turbulence that is nearly homogeneous and isotropic over many integral length and time scales. While laminar-flame propagation is found to be influenced by the Darrieus– Landau instability and heat loss to the walls of the apparatus, turbulent-flame propag...

Performing high-fidelity simulations of complex reacting flows requires that the uncertainties associated with predictions of fundamental flame properties are characterized and minimized. Although the kinetics of C1-C4 hydrocarbon flames have been studied extensively in numerous past investigations, notable uncertainties exist. In the present study, the types of hydrocarbon fuels with the great...

We present the use of simultaneous Particle Streak Velocimetry (PSV) and CH Planar Laser Induced Fluorescence (PLIF) diagnostics in the study of planar, strained, premixed, methane-air flames, stabilized in a jet-wall stagnation flow. Both PSV and PLIF data are imaged at high spatial resolution and sufficiently high framing rates to permit an assessment of flame planarity and stability. Concurr...

The unresolved Q-branch profiles in the Raman spectra of' nitrogen in premixed, laminar, methane-air, propane-air and butane-air flames with lean to stoichiometric fuel-air equivalence ratios have been recorded experimentally and used to determine flame temperature s with a precision of about 10f0using an iterative computer program which fitted calculated nitrogen spectra to the experimentally ...