相关论文: Modeling of a self-sustaining ignition in a solid …
When designing high-efficiency spark-ignition (SI) engines to operate at high compression ratios, one of the main issues that have to be addressed is detonation development from a pre-ignition front. In order to control this phenomenon, it…
Regions of energy localization referred to as hotspots are known to govern shock initiation and the run-to-detonation in energetic materials. Mounting computational evidence points to accelerated chemistry in hotspots from large…
Ignition of iron particles in an oxidizing environment marks the onset of a self-sustained combustion. The objective of the current study is to quantitatively examine the ignition characteristics of fine iron particles governed by the…
Understanding the mechanisms of explosions is important for minimizing devastating hazards. Due to the complexity of real chemistry, a single-step reaction mechanism is usually used for theoretical and numerical studies. The purpose of this…
In energetic materials, the localization of energy into "hotspots" when a shock wave interacts with the material's microstructure is known to dictate the initiation of chemical reactions and detonation. Recent results have shown that,…
Theory and computations have established that thermodynamic gradients created by hot spots in reactive gas mixtures can lead to spontaneous detonation initiation. However, the current laminar theory of the temperature-gradient mechanism for…
Initiation in heterogeneous energetic material (HEM) subjected to shock loading occurs due to the formation of hot spots. The criticality of the hot spots governs the initiation and sensitivity of HEMs. In porous energetic materials,…
We study a flame propagating in the gaseous combustible mixture with suspended inert particles. The gas is assumed to be transparent for the radiation emitted by the combustion products, while particles absorb and re-emit the radiation.…
Different simplified and detailed chemical models and their impact on simulations of combustion regimes initiating by the initial temperature gradient in methane/air mixtures are studied. The limits of the regimes of reaction wave…
Despite over forty years of active research, the nature of the white dwarf progenitors of Type Ia supernovae remains unclear. However, in the last decade, various progenitor scenarios have highlighted the need for detonations to be the…
The details of ignition of Type Ia supernovae remain fuzzy, despite the importance of this input for any large-scale model of the final explosion. Here, we begin a process of understanding the ignition of these hotspots by examining the…
Electromagnetic stimulation of energetic materials provides a noninvasive and nondestructive tool for detecting and identifying explosives. We combine structural information based on X-ray computed tomography, experimental dielectric data,…
Two-dimensional simulations are conducted to investigate the direct initiation of cylindrical detonation in hydrogen/air mixtures with detailed chemistry. The effects of hotspot condition and mixture composition gradient on detonation…
The mechanisms of direct detonation initiation (DDI) in methane/air mixtures containing coal particles are investigated through simulations conducted using the Eulerian-Lagrangian method in a two-dimensional configuration. Methane-air…
The proposed fast ignition of highly compressed deuterium-tritium (DT) targets by petawatt lasers requires energy of about 100kJ. To lower the power of the laser, it is proposed to accomplish fast ignition with two lasers, one with lower…
We study the initiation of thermonuclear detonations in tidally disrupted white dwarf stars by intermediate-mass ($10^3 M_\odot$) black holes. The length scales required to resolve the initiation mechanism are not easily reached in…
Turbulence enhances fusion reactivity, enabling ignition at lower temperature. A modified Lawson-like ignition criterion is derived for inertially confined plasmas harboring turbulent kinetic energy. Remarkably, if small-scale turbulence is…
We present hybrid PIC simulations of fast electron transport and energy deposition in pre-compressed fusion targets, taking full account of collective magnetic effects and the hydrodynamic response of the background plasma. Results on…
A theoretical model is considered to predict the minimum ambient gas temperature at which fine iron particles can undergo thermal runaway--the ignition temperature. The model accounts for Knudsen transition transport effects, which become…
Crystals of energetic materials, such as HMX, embedded in plastic binders are the building blocks of plastic-bonded explosives. Such heterogeneous energetic materials contain microstructural features such as sharp corners, interfaces…