The behaviour of five landscape fire models (CAFE, FIRESCAPE, LAMOS(HS), LANDSUM and SEMLAND) was compared in a standardised modelling experiment. The importance of fuel management approach, fuel management effort, ignition management effort and weather in determining variation in area burned and number of edge pixels burned (a measure of potential impact on assets adjacent to fire-prone landsc...

The effect of steady strain on the transient autoignition of n-heptane at high pressures is studied numerically with detailed chemistry and transport in a counterflow configuration. Skeletal and reduced n-heptane mechanisms are developed and validated against experiments over a range of pressure and stoichiometries. Two configurations are investigated using the skeletal mechanism. First, the ef...

LLE Review, Volume 141 48 Introduction Shock ignition (SI)1–5 is an advanced concept in inertial confinement fusion (ICF)6 that is very promising and has the potential to provide significantly higher gains than conventional hot-spot ignition.7 SI is a two-step process where the fuel compression and ignition phases are separated by applying a highly shaped laser pulse with a duration of several ...

Simulations of forced ignition of non-premixed laminar counterflow flames are used to study the effect of strain rate on ignition success. A one dimensional calculation is performed, using detailed methane chemical kinetics and treating the spark as an instantaneous heat release in an inert mixing layer. Ignition success depends on the mixture composition at the spark location, resulting in lea...

As an attempt at providing insight to develop better modeling strategies for HCCI engines, the ignition and propagation of a reaction front in a premixed fuel/air stream mixed with hotter exhaust gases is computationally investigated using the opposed-flow configuration. The effects of heat and radical transport are studied by imposing various mixing rates on the system. The results show that t...

The effects of hydrogen-enriched biogas on combustion and emissions a dual-fuel spark-ignition engine with different hydrogen concentration ratios were studied numerically. A 1-cylinder spark ignition was used to perform numerical simulation. To reveal the influence compression gaseous engine, crankshaft modified generate 8.5, 9.0, 9.4, 10.0, 10.4. contained 60 40% methane (CH4) carbon dioxide ...

gas motion within the cylinder is one of the major factors that control the combustion process in spark ignition engine. it also has significant impact on heat transfer. both the bulk gas motion and the turbulence characteristics of the flow are important and governing the overall behavior of the flow. an arrangement for obtaining a stratified charge, using port injection, is proposed for a cur...

The ignition of a laminar non-premixed H2/air mixing layer with an embedded vortex was computationally studied with detailed chemistry and transport. The initial vortex velocity and pressure fields were specified based on the stream function of an incompressible nonviscous vortex. The fuel side is pure hydrogen at 300 K, and the oxidizer side is air at 2000 K. The vortex evolution process was f...

This paper presents a computational algorithm to predict highly-transient ame behavior in counter ow situations. The rst objective of the paper is to extend the transient counter ow problem to incorporate some gasdynamic compressibility e ects, yet retain the desirable similarity structure. By relaxing assumptions in earlier formulations, the computational algorithms can deliver high accuracy e...

The research presented here describes the numerical optimization of a multi-step ignition model to predict the auto-ignition of dimethyl ether (DME) in a rapid compression machine. The multi-step modeling concept is aimed at capturing the ignition behavior of new oxygenated fuel blends, where detailed or reducedmechanisms are not available. Experimental data for the ignition ofDME/O2/N2mixtures...