where ~ = (Kp/rR ) '~ is the weighted nongreyness, K p and r R are the Planck mean and the Rosseland mean of the absorption coefficient, r = rM6 K is optical thickness, r M = (rprR)'/~ the mean absorption, 8 K the conduction flame thickness, P = 4o TM3/(~5 K) the Planck number, T M the adiabatic flame temperature, ~ the thermal conductivity, and w the albedo, the ratio of scattering to extinction.

In this study, the effect of the levels of hydrogen addition to methane-air premixed flame in a micro-stepped reactor has been studied numerically. In addition, the effects of mixture velocity and walls’ thermal conductivity (Kw) on the flame’s location, temperature, and species distribution in a micro reactor were calculated using a 2D numerical laminar steady code. The results ...

In this study, the effect of the levels of hydrogen addition to methane-air premixed flame in a micro-stepped reactor has been studied numerically. In addition, the effects of mixture velocity and walls’ thermal conductivity (Kw) on the flame’s location, temperature, and species distribution in a micro reactor were calculated using a 2D numerical laminar steady code. The results showed that an ...

Spherical diffusion flames supported on a porous sphere were studied numerically and experimentally. Experiments were performed in 2.2 s and 5.2 s microgravity facilities. Numerical results were obtained from a Chemkin-based program. The program simulates flow from a porous sphere into a quiescent environment, yields both steady-state and transient results, and accounts for optically thick gas-...

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...

A laboratory combustor was used to investigate the factors that influence the conversion of fuel nitrogen in coal during coal combustion. Fuel NO was isolated by experimentation utilizing Argon/Oxygen/Carbon Dioxide mixtures as the oxidant, and care was taken to compare cases with air at matched conditions. For both well mixed and slowly mixed flame types, fuel NO contributed over 75% of the to...

TiAl with between 0 and 20 volume percent (v%)Ti5Si3 was produced by reactive sintering of cofd pressed compacts of elemental Ti, Al and Si powder mixtures at 7OO0C for 15 minutes in vacuum. The results show that adding Si to Ti and A1 reduces the swelling associated with reactive sintering of TiAI, as composites containing more than 5 vYoTigSi3 densified during reactive sintering. However, com...

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...