Temperature Of Explosion Research Articles

Flame propagation, explosion hazard, and pollutant emission characterization of typical clean fuels leaks in plateau low-pressure region

To accelerate energy transformation and sustainable development, various countries are rushing to lay hydrogen doped natural gas pipelines. However, the installation of pipelines will pass through plateau low-pressure region, and the impact of low-pressure environments on the flame propagation, explosion hazards, and pollutant emission characteristics of hydrogen doped natural gas is not yet clear. To solve this problem, a combination of constant volume combustion experiment and numerical simulations is used. The characterization parameters of flame, explosion and pollutant concentration of natural gas/H2/air under low-pressure environment are obtained, and their chemical reaction kinetics are analyzed. When the pressure drops, the laminar burning velocity (LBV) of them increases, and the Lewis number (Le) gradually increases by more than 1. Thermal diffusion is stronger than mass diffusion, and the growth rate of flame thickness exceeds 26 %. The effect of hydrodynamic instability enhances, causing an increment in the average size of flame cells, the critical instability radius, and the Markstein length (Lu). At the equivalent ratio (φ) of 1, there is a change from negative to positive in the Lu, and flame stability continuously strengthens. The explosion overpressure is reduced by 78 % to 90 %, the explosion temperature by 16 % to 20 %. As the φ increases, the LBV exhibits an inverted U-shaped relationship, reaching its maximum value near “φ = 1″. The flame stability first weakens and then strengthens. The explosion hazard is strongest in the range of ”φ = 1–1.2″. With a decrease in pressure, the total reaction rate of fuel consumption is reduced by more than 50 %. The continuous reaction distance is extended by 12 %. Changes in pressure have a relatively weak impact on the content of CO and CO2. The increase in the φ results in an increase in CO content of over 7 %. The content of CO2 reaches its maximum value around “φ = 1″. It is an essential reference for the safe delivery of hydrogen energy and the reduction of environmental pollution.

Preparation and Molecular Dynamic Simulation of Superfine CL-20/TNT Cocrystal Based on the Opposite Spray Method.

In view of the current problems of slow crystallization rate, varying grain sizes, complex process conditions, and low safety in the preparation of CL-20/TNT cocrystal explosives in the laboratory, an opposite spray crystallization method is provided to quickly prepare ultrafine explosive cocrystal particles. CL-20/TNT cocrystal explosive was prepared using this method, and the obtained cocrystal samples were characterized by electron microscopy morphology, differential thermal analysis, infrared spectroscopy, and X-ray diffraction analysis. The effects of spray temperature, feed ratio, and preparation method on the formation of explosive cocrystal were studied, and the process conditions of the pneumatic atomization spray crystallization method were optimized. The crystal plane binding energy and molecular interaction forces between CL-20 and TNT were obtained through molecular dynamic simulation, and the optimal binding crystal plane and cocrystal mechanism were analyzed. The theoretical calculation temperature of the binding energy was preliminarily explored in relation to the preparation process temperature of cocrystal explosives. The mechanical sensitivity of ultrafine CL-20/TNT cocrystal samples was tested. The results showed that choosing acetone as the cosolvent, a spraying temperature of 30 °C, and a feeding ratio of 1:1 was beneficial for the formation and growth of cocrystal. The prepared CL-20/TNT cocrystal has a particle size of approximately 10 μm. The grain size is small, and the crystallization rate is fast. The impact and friction sensitivity of ultrafine CL-20/TNT cocrystal samples were significantly reduced. The experimental process conditions are simple and easy to control, and the safety of the preparation process is high, providing certain technical support for the preparation of high-quality cocrystal explosives.

Effect of hydrogen concentration, initial pressure and temperature on mechanisms of hydrogen explosion in confined spaces

Hydrogen as a renewable clean energy raises industrial safety and environmental issues. Studying the mechanism of hydrogen explosion in confined space is significant for guiding the risk assessment and efficient use of hydrogen energy. This paper used a 20 L explosion chamber to explore the effect of initial concentration changes on the hydrogen explosion and verify the model, the CHEMKIN simulation software was used to qualitatively and quantitatively evaluate the dynamic behavior characteristics of hydrogen explosion in confined space under different initial conditions, and the variation law of physical process of hydrogen explosion under different influencing factors in confined space was revealed from macro-micro perspectives. This study shows that the maximum explosion temperature and pressure under fuel-rich conditions are generally higher than those under fuel-lean conditions. The induction period of the hydrogen explosion reaction gradually shortens as the initial pressure increases, there is a negative temperature coefficient effect of ignition delay at the initial temperature of 800 K. In addition, compared with the initial pressure, higher explosion temperature and faster reactant mixing speed significantly affect the gas explosion reaction rate. The molar fractions of free radicals H, O, and OH show an inverted V-shaped relationship with the initial hydrogen concentration, and there is a hysteresis phenomenon in the final molar fraction peak of H free radicals; Sensitivity analysis indicates that free radicals are mainly responsive to the intermediate reaction R16 (forward direction) and R9 (reverse direction), thereby affecting parameters such as explosion pressure and temperature. These research findings can provide theoretical support for developing hydrogen explosion suppression technology.

Progress in the preparation of biomass energy from steam-exploded lignocellulose

Steam explosion is an effective pretreatment method for the thermochemical conversion of biomass and an efficient way to produce sugars and fuels from lignocellulose. It breaks down the recalcitrant and complex structures in biomass, which are then converted into substances such as methane and fermentable sugars, and has great potential to mitigate global oil depletion and the threat of climate change. This review evaluates the effect of steam explosion temperature, dimension pressure time, and additive type factors on the pretreatment effect of the steam explosion method. The changes in the content and physical structure of the components in the treated biomass are also explored. The advantages and disadvantages of this means for the subsequent process and its application in industrial production are analyzed in depth to provide technical reference for steam explosion in the preparation of biomass from lignocellulose.

Study on the influencing factors of gas-liquid two-phase explosions of hybrid methane/isoprene on the basis of bush fires

To evaluate the explosion hazard of hybrid isoprene/biogas in a primary forest environment, a 20 L spherical explosion vessel combining with a colorimetric thermometry was used to study the explosion parameters, flame structures and temperature distributions of hybrid isoprene/methane at different methane content and initial temperatures. Furthermore, the relationships between the explosion gas products and explosibility of hybrid isoprene/methane were analyzed. Experimental results showed that when the mass concentration of isoprene was 272.4 g m−3, the explosion pressure, the pressure rising rate, and the average combustion temperature reached their peak values of 0.89 MPa, 63.9 MPa s−1 and 2216 K, respectively. When the mass concentration was fixed at 272.4 g m−3, the explosibility of hybrid isoprene/methane initially enhanced and then decreased with the increasing methane volume fraction, and got the maximum values at 5 vol% methane. It was worth noting that the explosibility of hybrid methane/isoprene weakened continuously as the initial temperature increased, and it exhibited a stronger explosion power at a lower temperature. The research results would be helpful for understanding the deflagration processes and mechanisms of bush fires under various conditions, providing scientific basis for the formulation of its prevention and control measures.

Impact of Intermediate Species in Simulating Oblique Detonation with Pre-Vaporized N-Decane/air Mixtures Substituting for Kerosene/Air Mixtures

ABSTRACT A renewed two-step n-decane mechanism is presented to improve reliable and robust simulation results, substituting for kerosene. This mechanism demonstrates that effective control of ignition delay time and heat release, based on the Chapman – Jouguet condition, enables successful simulation of oblique detonation waves. Chain reactions influence the overall reaction heat and explosion temperature, especially in simplified mechanisms with few steps. Therefore, carbon monoxide (CO) generation is crucial for balancing the overall reaction heat and reducing species sensitivity to pressure, a factor previously not discussed in simplified models. The computational time for solving detailed chemical kinetics increases exponentially with species count, driving the pursuit for further reduction in kinetic mechanism size. The sensitive interaction between density and temperature during the fuel/air mixture explosion process affects initiation zone formation and cellular structure. Analyzing the distribution of CO can provide insights into structural details. The study considers applying the Rankine – Hugoniot curve to confirm detonation speeds, temperatures, and kinetic energy changes induced by chemical reactions.

Effect of Cubic Crystal Morphology on Thermal Characteristics and Mechanical Sensitivity of PYX

To investigate the influence of the cubic crystal morphology on the thermal properties and sensitivity of 2,6-bis(picrylamino)-3,5-dinitropyridine (PYX), cubic PYX (CPYX) crystals were prepared using the antisolvent method. Scanning electron microscopy (SEM), laser particle size analysis, X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR) were used to characterize the morphology, particle size and structure of the prepared products. The thermal behavior, thermal decomposition kinetics, thermal safety parameters and thermal decomposition mechanism of CPYX were investigated by differential scanning calorimetry–thermogravimetry–mass spectrometry–Fourier transform infrared spectrometry (DSC-TG-MS-FT-IR) and in situ FT-IR experiments. Meanwhile, the mechanical sensitivity of CPYX was determined by means of the explosion probability method. The results showed that the product had a smooth cubic morphology and small crystal aspect ratio with an average particle size (d50) of 10.65 μm, but it had no distinct differences from the crystal structure of raw PYX (RPYX). The thermal decomposition peak temperature, the self-accelerating decomposition temperature and the critical temperature of the thermal explosion of CPYX increased by 7.2 °C, 6.1 °C and 10.4 °C, respectively, compared to RPYX. Similarly, the apparent activation energy increased by 15%. Besides these, the impact sensitivity and friction sensitivity of CPYX decreased by 36% and 20%, respectively, compared to RPYX. The decomposition process of CPYX contains two stages. The first stage involves the breakage of N-H bonds and -NO2 groups with the release of CO2, N2O, NO, HCN and H2O, followed by the thermal decomposition of the resulting intermediate and the release of CO2, N2O and HCN in the second stage.

Temperature response and chemical reactions of energetic materials under thermal radiation and heat conduction

Thermal radiation from a high-temperature source is the primary cause of energetic material explosions. However, current research cannot meet the need to prevent thermal radiation-caused explosions. This paper proposes a novel numerical calculation model for temperature response and the chemical reaction of energetic materials under thermal radiation based on the physical mechanisms and evolution of the thermal effect during the chain explosion accident. This model is essential for rapidly evaluating the effect of thermal radiation in chain explosion accidents. The numerical model in this study efficiently obtained the thermal response of energetic materials under thermal radiation, as well as the critical conditions for energetic material explosion under thermal radiation. The results reveal that heat conduction is difficult to cause the explosion of ammonium nitrate, but thermal radiation can. The critical temperature of explosion for ammonium nitrate is 1668 K, the critical duration is 15.93 s, and the critical distance is 7.85 m. The temperature, duration, and radiation distance of the heat source are crucial factors that induce the ammonium nitrate explosion. Firefighters must cover and protect ammonium nitrate within 7200 s and 15.93 s, respectively, when the external heat flow absorbed by the material is 2.688 kW/m2 and 28 kW/m2. The model proposed in this paper can predict the effect of thermal radiation once the heat source parameters are known. Besides, combined with machine learning, the model can also predict the heat source parameters once the parameters of the thermal radiation effect are known. Compared with the current numerical models to evaluate the effect of thermal radiation, the numerical model presented in this paper can evaluate the effect of thermal radiation in engineering more efficiently and has broad application prospects.

Dynamics of gas composition and thermal behavior post explosions: An experimental investigation across varied initial concentrations

Gas explosion accidents are a leading cause of casualties in underground coal mines. This study investigates the variation patterns of explosion temperature and pressure under different initial gas concentration conditions using a 20 L explosion characteristic test system and high-precision sensors. Accurate post-explosion gas analyses were conducted using a GC9560 gas chromatograph. Our research aligns with global research, finding that initial gas concentrations within the range of 5.8%–13.3% generate maximum explosion pressures between 0.3 and 0.9 MPa, posing a significant overpressure hazard to humans. Comprehensive fitting analyses of various post-explosion gases reveal that at an initial gas concentration of 10.6%, the produced H2 can reach its lower explosion limit, indicating a risk of secondary explosions. Furthermore, post-explosion CO levels can peak at 9.87%, potentially causing poisoning or death, while elevated CO2 levels and diminished O2 concentrations could lead to asphyxiation. A unique observation at a 9.5% concentration was a secondary temperature rise, with the relationship between temperature delay, heating time, and initial gas concentration presenting a U-shaped pattern that mirrors theoretical expectations. This study advances the field by addressing research gaps in post-explosion gas analysis and emphasizing the necessity of precise monitoring and control of gas concentrations, thereby offering novel insights and substantial theoretical and practical contributions to the prevention of gas explosion incidents in underground coal mines.

Characteristic Analysis and Risk Control of Syngas Explosion during Underground Coal Gasification.

Gas explosion is one of the main accident risks during underground coal gasification (UCG). There are significant differences in the gas composition and explosive environment between UCG syngas and other gases. Previous research on the explosion characteristics of UCG syngas is not comprehensive enough, especially without considering the influence of the initial temperature on various characteristic parameters. A set of calculation methods for explosion characteristic parameters of UCG syngas based on existing research was proposed, which was applied to analyze explosion characteristics of syngas produced by different gasifying processes in the Huating UCG industrial test. The results showed that with the initial temperature improving, the maximum temperature and upper explosion limit of different gases increased, while the maximum pressure, lower explosion limit, and oxygen content safety limit decreased. However, the explosion thermal effect, pressure rise rate, and explosion characteristic values showed small changes. When the initial temperature increased from 298 to 1473 K, the explosion temperature of different gas explosions increased from 1645-2286 to 2652-3238 K, the maximum pressure dropped from 0.59-0.81 MPa (absolute pressure) to 0.19-0.23 MPa, the lower explosion limit dropped from 12.34-29.79% to 0.58-1.77%, the upper explosion limit increased from 55.68-83.35% to 70.89-93.73%, and the safety limit of oxygen content dropped from 4.86-6.37% to 0.26-0.34%. In addition, the gas calorific value also affected the values of various explosion characteristic parameters, among which the explosive thermal effect, maximum temperature, maximum pressure, pressure rise rate, explosion characteristic value, and safety limit of oxygen content in the syngas were all proportional to the calorific value of gas, while the lower and upper limits of explosion were inversely proportional to it. Based on the above research, syngas explosion-prone stages and causes of each potential risk area in the Huating UCG project were analyzed, the explosion characteristic parameters were determined, and targeted prevention and control measures were proposed accordingly. This study can lay a theoretical foundation for the study of syngas explosion characteristics and risk control for the UCG project.

Development and investigation of a porous metal-ceramic substrate for solid oxide fuel cells

The process of creating a porous metal-ceramic material based on Ni-Al alloy and gadolinium-doped cerium oxide (CGO) using the thermal explosion method has been investigated. This study aims to analyze the effect of CGO on the thermal explosion parameters and the architecture of the resulting Ni-Al-CGO materials. In this regard, the influence of adding CGO powder to the Ni-Al system on the synthesis process and structure formation during controlled heat loss thermal explosion has been studied. Dependencies of temperature and time characteristics of the thermal explosion on initial parameters have been measured. It has been demonstrated that the concentration of CGO in the initial mixture and heat dissipation from the sample significantly affect the rate of the exothermic reaction. The phase composition of the obtained porous materials, depending on the CGO content and the temperature of subsequent vacuum annealing, was analyzed using X-ray diffraction. The chemical composition and microstructure of the synthesis products were examined through electron microscopy and energy-dispersive X-ray spectroscopy. The possibility of forming metal-ceramic composites with a porosity of 60–65 % for use as supporting substrates for solid oxide fuel cells with a NiO/CGO anode has been shown. An anodic layer of NiO/CGO was applied to a metal-ceramic base of the composition (Ni+25 %Al)+5 %CGO using screen printing, which was then annealed in an air atmosphere at 1300 °C and reduced at 900 °C in a hydrogen atmosphere. The dilatometric method determined that adding 40 wt.% Cr to a mixture of Ni-Al powders reduces the average coefficient of thermal expansion of the new material.

Analysis method of explosive electromagnetic radiation energy

AbstractThe energy of electromagnetic radiation from explosions is coupled to electronic equipment circuits, disrupting the initiation sequence or causing failure in an increasing number of cases, which seriously affects the stability of weapon systems. There is a significant difference between the characteristics of the explosive electromagnetic radiation signals and modulated electromagnetic signals. The electric field intensity and signal power cannot directly represent the magnitude of the explosive electromagnetic radiation energy, and traditional electromagnetic signal analysis methods are unsuitable for explosion electromagnetic signal analysis. To solve this problem, the mechanism of explosive electromagnetic radiation was first analyzed. Through verification experiments of the explosion electromagnetic intensity and temperature, it was concluded that there is a strong correlation between the explosion plasma temperature and electromagnetic intensity. The temperature of the explosive plasma is derived based on the measured surface temperature of the explosive fireball, a functional relationship is established between the energy of the explosive plasma and the temperature of the plasma, and plasma energy is introduced as a parameter for electric field intensity correction. The interference signal analysis method based on eye diagram is used to calibrate the electromagnetic radiation damage ability, achieving quantitative analysis of the interference degree of electromagnetic radiation energy on the signal, and providing a new approach for the analysis of explosive electromagnetic radiation energy.

ОПРЕДЕЛЕНИЕ РАЦИОНАЛЬНЫХ РЕЖИМНЫХ ПАРАМЕТРОВ ФЕРМЕНТАЦИИ БИОВОДОРОДА С ИСПОЛЬЗОВАНИЕМ CLOSTRIDIUM BUTYRICUM И ENTEROBACTER CLOACAE НА ГИДРОЛИЗАТАХ СОЛОМЫ, АКТИВИРОВАННОЙ ПАРОВЗРЫВНОЙ ОБРАБОТКОЙ

Studies have been conducted to determine the possibility of using agricultural waste, in particular straw, for the production of biohydrogen. In our work, we used two types of straw hydrolysates (after acidic and enzymatic hydrolysis), pre-activated by steam blasting at steam temperatures of 100, 165, 210 0C. The hydrolysates were diluted with distilled water to a concentration of reducing agents (RR) equal to 1.0, 1.5 and 2.0% of their mass in order to determine the rational concentration. Two cultures of anaerobic microorganisms were tested on 18 samples of hydrolysates: a strain of bacteria of the genus Clostridium Butyricum E.VI .3.2.1 (no. VKPM B-9619), a strain of bacteria of the genus Enterobacter cloacae (no. VKPM B-1980). The fermentation temperature for all samples was set at 37 ± 0.5 0C, pH 5.5 ± 0.1. The released gas accumulated in the gas tank; its samples were taken every 12 hours and analyzed for the volume content of hydrogen. After establishing the rational initial concentration of the substrate, the temperature of steam explosive activation of straw, the type of hydrolysate and the maximum yield of biohydrogen, the cultivation temperature and pH for each culture were further changed in order to determine the rational parameters: for Clostridium Butyricum, the cultivation temperature was set to 32 ±0.5, 37 ±0.5 and 42±0.5 0C for Enterobacter cloacae – 36±0.5, 37±0.5, 38±0.5 0C; the pH for all samples was set in the range of 5...6 in increments of 0.5 ± 0.1). On acidic straw hydrolysates, Clostridium Butyricum demonstrated the best productivity (steam explosion temperature 165 0C) - hydrogen yield was 73 ml/g, on hydrolysates fermented by Enterobacter cloacae (steam explosion temperature 210 0C), hydrogen yield was 50 ml/g. Both cultures are capable of producing the maximum amount of hydrogen at a concentration of reducing substances of 2%. The rational fermentation temperature for Clostridium Butyricum is 37 ± 0.5 0C, for Enterobacter cloacae – 36 ± 0.50 C, for both cultures – pH = 6.

Steam explosion technology as a tool to alter the physicochemical properties of intermediate wheatgrass (Thinopyrum intermedium) bran

Products containing the perennial grain intermediate wheatgrass (IWG) have recently entered the market, but little is known about the effect of processing operations on its constituents. This study investigated the effect of steam explosion (SE) conditions, i.e., temperature (130, 150 or 170 °C) and residence time (5 or 10 min), spanning severity factors from 1.6 to 3.1, on physicochemical properties of IWG bran. Even the lowest temperature and shortest time combination (130 °C, 5 min), was sufficient to inactivate peroxidase, generally regarded as the most heat-stable enzyme in grains. Contents of free phenolic acids as well as water-extractable arabinoxylans significantly increased while phytic acid was reduced after SE. However, starch damage, free fatty acids as well as browning (all negatively affecting quality) increased with treatment severity. Thus, SE is a promising technology to reduce enzymatic activity, enhance phenolic and soluble fiber contents in IWG bran, but severity factors >2.5 may negatively affect quality.

The overpressure and temperature characteristics of high volatile liquid fuel explosions in extreme environments: Effects of low initial ambient temperatures and pressures

The explosion characteristics of petroleum ether-epoxy propane-air mixtures were studied in a 20 L spherical explosion vessel at low initial ambient temperatures (243–293 K) and absolute pressures (61.3–101.3 kPa). The effects of variations in single and coupled ambient conditions on the explosion pressure and temperature of high volatile liquid fuels were obtained through a series of experiments. The results showed that the peak explosion pressure and temperature were invertedly correlated with ambient temperature, and decreased with decreasing ambient pressure. Compared to ambient pressure, ambient temperature had a greater influence on explosion temperature, while ambient pressure had a greater influence on explosion pressure than ambient temperature. The variations of peak explosion pressure and temperature were more significant under the coupled effects of low temperature and pressure. Based on these results, the effects of low ambient temperature and pressure on the explosion characteristics of high volatile liquid fuels were systematically investigated, and a prediction model for peak explosion pressure and temperature was proposed.

A novel measurement strategy for explosion temperature field towards enhancing the fire process safety

Chemical explosives such as TNT are widely used in special scenarios, such as civil explosives, due to their simple preparation and high energy density. However, the temperature of the fireball produced by the explosion of these explosives is extremely high. Moreover, this approach may cause many casualties and economic losses if not prevented. To accurately measure the temperature of a transient explosion field and study its space-time distribution, a two-dimensional high-speed temperature measurement system was built based on blackbody radiation theory, high-speed photography, image Bayer array and improved interpolation algorithm. The explosive fireball produced in a static explosion test of 10 kg of TNT was measured within the shooting range. TNT was added with an auxiliary blackbody (tungsten). Compared to traditional explosion temperature measurement methods, the experimental results showed that the colorimetric temperature measurement method based on the improved interpolation algorithm and the addition of tungsten powder could more accurately measure the temporal and spatial distributions of the temperature field. This work can aid in the prevention in the accidents during the transportation, storage, and manufacturing of chemicals relevant to process industries.

Characterization of the deflagration behavior of the lithium-ion battery module within a confined space under different ventilation conditions

Lithium-ion batteries (LIBs) have been widely used in the modern society, such as electric vehicle and energy storage system. The most common application scenario of LIB is in the confined space. LIBs were prone to release flammable gases (such as carbon monoxide, hydrogen, and hydrocarbons) under abuse conditions, and the gas accumulation deflagrated with catastrophic power especially in the confined space. The ventilation condition and cathode materials of the LIB influence the destructive power of deflagration. In this study, thermal runaway (TR) tests on the Li(Ni0.8Co0.1Mn0.1)O2 (NCM811) and Li(Ni0.6Co0.2Mn0.2)O2 (NCM622) cells with different states of charge (SOCs) were conducted in a confined box under different ventilation conditions. The location of peak pressure, gas temperature, deflagration pressure, and the effects of ventilation were analyzed. Based on the measured values of the pressure at different locations, the peak pressure was generally located at the top of the confined space. The gas temperature and pressure of NCM811 batteries were generally higher than those of NCM622 batteries. NCM811 cells not only had a lower trigger temperature of thermal runaway (TR), but also a high destructive power of deflagration. The impact of ventilation condition on deflagration was studied, and the result of dimensionless analysis indicated that the deflagration pressure was influenced by opening factor, explosion gas volume, explosion heat, and explosion temperature. With the increasing of the opening angle of the window, the peak deflagration pressure firstly increased (from 30° to 60°) then decreased, indicating that there was an competitive mechanism between the combustion and pressure relief with the improvement of ventilation condition. This work helps us understand the hazards of LIB deflagration under different ventilation conditions and provides a reference for ventilation design in battery application scenarios which ensure the process safety through fire protection design.

Thermal decomposition kinetics and compatibility of NH3OHN5

AbstractHydroxylammonium cyclo‐pentazolate (NH3OHN5), as one of the poly‐nitrogen compounds, has a broad prospect in the field of energetic materials, due to its high specific impulse, high detonation velocity, and the pollution‐free products. In this paper, the thermal decomposition behavior of NH3OHN5 was studied by differential scanning calorimetry (DSC) using four heating rates (2, 5, 8, 10 °C min−1). The apparent activation energy (EK,O=114.31 kJ mol−1), the pre‐exponential factor (AK=4.78×1011 s−1) and the critical temperature of the thermal explosion (Tb=108.08 °C) of NH3OHN5 were calculated by Kissinger and Ozawa method under non‐isothermal heating conditions. The compatibility of NH3OHN5 with 1,3,5‐trinitro‐1,3,5‐triazacyclohexane (RDX), 1,3,5,7‐tetranitro‐1,3,5,7‐tetraazacyclooctane (HMX), 2,4,6,8,10,12‐hexanitro‐2,4,6,8,10,12‐hexaza‐isowurtzitane (CL‐20), ammonium perchlorate (AP), and hydroxy‐terminated polybutadiene (HTPB) were tested and judged based on a standard agreement (STANAG‐4147). The DSC results showed that NH3OHN5/HMX, NH3OHN5/RDX, NH3OHN5/CL‐20, NH3OHN5/AP and NH3OHN5/HTPB had good compatibility.

A study on the damage characteristics of glass under the combined effects of explosion and high temperature: An analysis using peridynamics

Statistics from explosion incidents indicate that the primary cause of casualties in such events is often flying glass fragments, frequently accompanied by fires. This study investigates the damage mechanisms of glass under the combined effects of explosions and high temperatures, examining its dynamic response to blast loads. We simulate the dynamic response of glass under blast impact at both ambient and high temperatures using the peridynamics (PD) algorithm. The results show that the glass edges experience the highest stress, leading to the initial formation of cracks in these areas under various conditions. Additionally, increased stress causes more pulverization of fragments at the edge. Comparative analysis of the crack initiation process under different conditions reveals significant behavioral differences in glass with varying load-resistance capabilities when exposed to impact loads. At high temperatures, crack development is predominantly influenced by the impact load, diminishing the effect of stress transfer on the expansion of glass cracks. The findings of this research provide theoretical insights into the destructive mechanisms of glass under the combined influence of explosions and high temperatures, contributing to the design of blast-resistant glass.

Experimental Study on the Explosion Parameters of n-Decane Aerosol under Saturated Vapor Pressure.

This research aims to conduct a comprehensive investigation and analysis of the effects of particle size and concentration on crucial explosion parameters in n-decane aerosols. Two sets of n-decane aerosols with different concentrations were initially measured, with Sauter mean diameters of 22 and 38 μm, respectively. These measurements served as the foundation for understanding the impact of the particle size on explosion parameters. Subsequently, experiments were performed on n-decane aerosols with various concentrations, utilizing an ignition energy of 40.32 J. The analysis focused on critical explosion parameters including the lower flammability limit, explosion pressure, explosion temperature, and flame propagation delay time. Through thorough examination of the data obtained from these experiments, the research elucidated the relationship between n-decane concentration, particle size, and these explosion parameters.