A novel ignition hohlraum for indirect-drive inertial confinement fusion is proposed, which is named three-axis cylindrical hohlraum (TACH). TACH is a kind of 6 laser entrance holes (LEHs) hohlraum, which is orthogonally jointed of three cylindrical hohlraums. Laser beams are injected through every entrance hole with the same incident angle of 55°. A view-factor simulation result shows that the...

Fire simulation studies that use models such as FARSITE often assume that ignition locations are distributed randomly, because spatially explicit information about actual ignition locations are difficult to obtain. However, many studies show that the spatial distribution of ignition locations, whether humancaused or natural, is non-random. Thus, predictions from fire simulations based on random...

The influence of square corners on the ignition of a solid exposed to a step in surface temperature is analyzed by means of large activation energy asymptotics. This study begins by considering the case of a semi-infinite square corner, applicable to the ignition of finite bodies with square corners when the reaction is very fast. Two spatial zones (reactive and inert) and two time stages (init...

A large eddy simulation (LES) model was developed to simulate the combustion process in a spark-assisted homogeneous charge compression ignition (SACI) engine. First, an ignition and flame propagation model based on a reaction progress variable is presented. The reaction progress variable is defined based on the normalized cumulative heat release. Transport equation for the progress variable is...

Iso-octane ignition delay times (τign) and hydroxyl (OH) radical mole fraction (χOH) time histories were measured under conditions relevant to homogeneous charge compression ignition engine operating regimes using the University of Michigan rapid compression facility. Absolute quantitative OH mole fraction time histories were obtained using differential narrow-line laser absorption of the R1(5)...

A research program studying the oxidation and ignition characteristics of hydrocarbon fuels has been conducted. The program was initiated in October 1985 with the awarding of a research grant through the Army Research Office (Grant No. DAAG 29-85-K-0253, Project No. 22437-EG) and ran through November 1989. The research program entailed mechanistic studies examining the oxidation chemistry of si...

1 SUMMARY To reduce the frequency of electrically initiated, 20mm munition hangfires (delayed ignitions), a joint Army/NASA investigation was conducted to recommend quality evaluation improvements for acceptance of both primers and gun propellant. This effort focused only on evaluating ignition and combustion performance as potential causes of hangfires: poor electrical initiation of the primer...

in this research an algorithm based on monte carlo simulation is introduced to assess the risk of fire following earthquake in residential, industrial, educational, and governmental land-uses in district no. 20 of tehran. the proposed algorithm consist of different modules including hazard analysis, vulnerability assessment, leak and break analysis of damaged pipeline, ignition probability anal...

We investigate the consequences of a new phenomenological model prediction of strongly reduced low-energy astrophysical S-factors for carbon and oxygen fusion reactions on stellar burning and nucleosynthesis. The new model drastically reduces the reaction rates in stellar matter at temperatures T < ∼ (3–10) × 108 K, especially at densities ρ >∼ 109 g cm−3, in a strongly screened or even pycnonu...

This paper deals with the steady state catalytic ignition of premixed gases over a flat píate of finite thickness. An external heat flux is added to the píate to facilítate the ignition process. The influence of the finite thermal conductivity of the píate on the catalytic ignition is evaluated in the two distinct limits of the reduced Damkohler number of order of unity and much less than unity...