The effect of thermal stratification on the ignition of a lean homogeneous n-heptane/air mixture at constant volume and high pressure is investigated by direct numerical simulations (DNS) with a new 58species reduced kinetic mechanism developed for very lean mixtures from the detailed LLNL mechanism (H.J. Curran et al., Combust. Flame 129 (2002) 253–280). Two-dimensional DNS are performed in a ...

Ignition behavior of bituminous coal dust deposited between two hot surfaces forming wedges of 60º, and 90º is experimentally studied. Three thermocouples placed along the symmetry plane of the wedge cross-section at various heights from the apex (lowermost, middle and top) are used to record the transient temperature data. Results show that the ignition always occurs around the region surround...

The homogeneous (gas-phase) and heterogeneous (catalytic) ignition of fuel-lean premixtures is investigated analytically and numerically in two-dimensional laminar channel-flow configurations with uniform incoming properties and isothermal catalytic walls. First-order matched activation energy asymptotics are employed, along with a one-step catalytic reaction and a one-step large activation ene...

We present a model that simulates the conventional tube-furnace experiment used for ignition studies. The Distributed Activation Energy Model of Ignition accounts for particle-to-particle variations in reactivity by having a single preexponential factor and a Gaussian distribution of activation energies among the particles. The results show that the model captures the key experimental observati...

Engine performance depends on two main factors of engine speed and ignition time. Ignition timing can affect engine life, fuel economy and engine power. In this paper, to study engine performance of Peugeot 206 TU3A with comparison ratio of 10.5:1 and displacement of 1361CC in MATLAB software, a two-zone burned/unburned model with the fuel burning rate described by aWiebe function was used for ...

Flame ignition by short-duration (≈ 50 ns) transient plasma, or corona, discharges was investigated for methane-air, propane-air and butane-air mixtures at atmospheric and elevated pressures. Such discharges produce a larger fraction of high-energy electrons, yield more spatially distributed energy and deposit energy in the gas more efficiently than conventional arc discharges do. We show that ...

Simulations of forced ignition in a non-premixed laminar counterflow are used to study the effect of the strain rate on ignition success. A one dimensional calculation is performed, using detailed methane chemical kinetics, and treating the ignition event as an instantaneous heat release. Ignition success is seen to depend on the mixture composition and spark location, resulting in lean and ric...

This study aims at modeling the effect of incoming heat flux fluctuations on solid material ignition. In order to propose a general methodology that can be applied to any kind of solid target, kernels accounting for the target temperature response regarding an incoming heat flux are developed for thermally thick and thin solids with low or high thermal inertia. The expected behavior of these di...

LLE Review, Volume 134 127 Introduction The cone-guided scheme for fast-ignition inertial confinement fusion (ICF)1,2 provides the potential of higher gains at lower total driver energy than conventional central hot-spot–ignition schemes. In this scheme, a spherical target with a hollow gold cone attached is first compressed by laser beams outside the cone and then ignited by a petawatt (PW) sh...