Engineering › Aerospace Engineering

Combustion and Detonation Processes

Works Count: 61446

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Description

This cluster of papers focuses on the challenges, applications, and research developments in detonation propulsion technology, including pulse detonation engines, rotating detonation combustors, flame acceleration, detonation-to-deflagration transition, hydrogen safety, and dust explosions. It explores the fundamental combustion dynamics and explosion characteristics relevant to the advancement of detonative propulsion systems.

Keywords

Detonation Propulsion; Pulse Detonation Engines; Rotating Detonation Combustors; Flame Acceleration; Detonation-to-Deflagration Transition; Hydrogen Safety; Dust Explosions; Flame Propagation; Explosion Characteristics; Combustion Dynamics

Accumulation of errors in numerical simulations of chemically reacting gas dynamics

2015-09-07

Н.Н. Смирнов , В. Б. Бетелин , В. Ф. Никитин +2 more

Combustion, Flames and Explosions of Gases

1961-01-01

Bernard Lewis , Guenther von Elbe

Compression-Ignited Homogeneous Charge Combustion

1983-02-01

Paul Najt , David E. Foster

Experimentally obtained energy release results, a semi-empirical ignition model, and an empirical energy release equation developed during this research were used to evaluate the combustion of compression-ignited homogeneous mixtures of … Experimentally obtained energy release results, a semi-empirical ignition model, and an empirical energy release equation developed during this research were used to evaluate the combustion of compression-ignited homogeneous mixtures of fuel, air, and exhaust products in a CFR engine. A systematic study was carried out to evaluate the response of compression-ignited homogeneous charge (CIHC) combustion to changes in operating parameters with emphasis being placed on the phenomena involved rather than the detailed chemical kinetics. This systematic study revealed that the response of the combustion process to changes in operating parameters can be explained in terms of known chemical kinetics, and that through the proper use of temperature and species concentrations the oxidation kinetics of hydrocarbon fuels can be sufficiently controlled to allow an engine to be operated in a compression-ignited homogeneous charge combustion mode.

Numerical modeling of detonations

1979-01-01

Charles L. Mader

Rate Coefficients in the C/H/O System

1984-01-01

Jürgen Warnatz

The Mathematical Theory of Combustion and Explosions

1985-01-01

Ya. B. Zel’dovich , Г. И. Баренблатт , V. B. Librovich +1 more

Limits of Flammability of Gases and Vapors

1952-01-01

Hubert Frank Coward , Gary Jones

From Definitions: This bulletin presents the results of a critical review of all figures published on the limits of flammability if combustible gases and vapors when admixed with air, oxygen,or … From Definitions: This bulletin presents the results of a critical review of all figures published on the limits of flammability if combustible gases and vapors when admixed with air, oxygen,or other atmosphere.

Flammability characteristics of combustible gases and vapors

1964-05-01

M.G. Zabetakis

This is a summary of the available limit of flammability, autoignition and burning-rate data for more than 200 combustible gases and vapors in air and other oxidants, as well as … This is a summary of the available limit of flammability, autoignition and burning-rate data for more than 200 combustible gases and vapors in air and other oxidants, as well as of empirical rules and graphs that can be used to predict similar data for thousands of other combustibles under a variety of environmental conditions. Spec$c data are presented on the paraffinic, unsaturated, aromatic, and alicyclic hydrocarbons, alcohols, ethers, aldehydes, ketones, and sulfur compounds, and an assortment of fuels, fuel blends, hydraulic fluids, engine oils, and miscellaneous combustible gases and vapors.

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Regime classification of an exothermic reaction with nonuniform initial conditions

1980-10-01

Y B Zeldovich

The Measurement of Laminar Burning Velocities and Markstein Numbers for Iso-octane–Air and Iso-octane–n-Heptane–Air Mixtures at Elevated Temperatures and Pressures in an Explosion Bomb

1998-10-01

D. Bradley , R. A. Hicks , M. Lawes +2 more

Hydrogen safety: The road toward green technology

2013-07-05

Yousef S.H. Najjar

Recent advances in understanding of flammability characteristics of hydrogen

2013-12-01

Antonio L. Sánchez , Forman A. Williams

The Dynamics of Explosion and Its Use

1980-03-01

Josef Henrych , G. R. Abrahamson

The dynamics of explosion and its use , The dynamics of explosion and its use , مرکز فناوری اطلاعات و اطلاع رسانی کشاورزی The dynamics of explosion and its use , The dynamics of explosion and its use , مرکز فناوری اطلاعات و اطلاع رسانی کشاورزی

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On the “tulip flame” phenomenon

1996-04-01

Christophe Clanet , Geoffrey Searby

Numerical Solutions of Spherical Blast Waves

1955-06-01

Harold L. Brode

The strong-shock, point-source solution and spherical isothermal distributions were used as initial conditions for a numerical integration of the differential equations of gas motion in Lagrangean form. The von Neumann-Richtmyer … The strong-shock, point-source solution and spherical isothermal distributions were used as initial conditions for a numerical integration of the differential equations of gas motion in Lagrangean form. The von Neumann-Richtmyer artificial viscosity was employed to avoid shock discontinuities. The solutions were carried from two thousand atmospheres to less than one-tenth atmospheres peak overpressure. Results include overpressure, density, particle velocity, and position as functions of time and space. The dynamic pressure, the positive and negative impulses of both dynamic pressure and static overpressure, positive and negative durations of pressure and velocity, and shock values of all quantities are also described for various times and radial distances. Analytical approximations to the numerical results are provided.

The formation of a blast wave by a very intense explosion. - II. The atomic explosion of 1945

1950-03-22

Geoffrey Ingram Taylor

Photographs by J. E. Mack of the first atomic explosion in New Mexico were measured, and the radius, R , of the luminous globe or ‘ball of fire’ which spread … Photographs by J. E. Mack of the first atomic explosion in New Mexico were measured, and the radius, R , of the luminous globe or ‘ball of fire’ which spread out from the centre was determined for a large range of values of t , the time measured from the start of the explosion. The relationship predicted in part I, namely, that R* would be proportional to t , is surprisingly accurately verified over a range from R = 20 to 185 m. The value of R" t-1 so found was used in conjunction with the formulae of part I to estimate the energy E which was generated in the explosion. The amount of this estimate depends on what value is assumed for y , the ratio of the specific heats of air. Two estimates are given in terms of the number of tons of the chemical explosive T.N.T. which would release the same energy. The first is probably the more accurate and is 16,800 tons. The second, which is 23,700 tons, probably overestimates the energy, but is included to show the amount of error which might be expected if the effect of radiation were neglected and that of high temperature on the specific heat of air were taken into account. Reasons are given for believing that these two effects neutralize one another. After the explosion a hemispherical volume of very hot gas is left behind and Mack’s photographs were used to measure the velocity of rise of the glowing centre of the heated volume. This velocity was found to be 35 m./sec. Until the hot air suffers turbulent mixing with the surrounding cold air it may be expected to rise like a large bubble in water. The radius of the ‘equivalent bubble’ is calculated and found to be 293 m. The vertical velocity of a bubble of this radius is 2/3 √(g 29300) or 35.7 m./sec. The agreement with the measured value, 35 m./sec., is better than the nature of the measurements permits one to expect.

Pulse detonation propulsion: challenges, current status, and future perspective

2004-01-01

G. D. Roy , S.M. Frolov , А. А. Борисов +1 more

Review of Propulsion Applications of Detonation Waves

2000-09-01

K. Kailasanath

Applications of detonations to propulsion are reviewed. First, the advantages of the detonation cycle over the constant pressure combustion cycle, typical of conventional propulsion engines, are discussed. Then the early … Applications of detonations to propulsion are reviewed. First, the advantages of the detonation cycle over the constant pressure combustion cycle, typical of conventional propulsion engines, are discussed. Then the early studies of standing normal detonations, intermittent (or pulsed) detonations, rotating detonations, and oblique shock-induced detonations are reviewed. This is followed by a brief discussion of detonation thrusters, lasersupported detonations and oblique detonation wave engines. Finally, a more detailed review of research during the past decade on ram accelerators and pulsed detonation engines is presented. The impact of the early work on these recent developments and some of the outstanding issues are also discussed.

Dust explosions–Cases, causes, consequences, and control

2006-11-14

S. A. Abbasi

Measurements of laminar burning velocities for natural gas–hydrogen–air mixtures

2006-04-18

Zuohua Huang , Youmin Zhang , Kehan Zeng +3 more

The burning velocity of methane-air mixtures

1972-10-01

Gordon E. Andrews , D. Bradley

Flame acceleration and transition to detonation in ducts

2008-02-20

G. Ciccarelli , S.B. Dorofeev

Ignition and devolatilization of pulverized bituminous coal particles during oxygen/carbon dioxide coal combustion

2006-09-27

Alejandro Molina , Christopher R. Shaddix

Intrinsic Localized Modes in Anharmonic Crystals

1988-08-22

A. J. Sievers , Sachio Takeno

A new kind of localized mode is proposed to occur in a pure anharmonic lattice. Its localization properties are similar to those of a localized mode for a force-constant defect … A new kind of localized mode is proposed to occur in a pure anharmonic lattice. Its localization properties are similar to those of a localized mode for a force-constant defect in a harmonic lattice. These modes, which are thermally generated like vacancies but with much smaller activation energies, may appear at cryogenic temperatures in strongly anharmonic solids such as quantum crystals as well as in conventional solids.

Origins of the deflagration-to-detonation transition in gas-phase combustion

2006-10-24

Elaine S. Oran , Vadim N. Gamezo

Dust explosions in the process industries

1992-05-01

Rolf K. Eckhoff

This work is a comprehensive account of the existing practical and theoretical knowledge of the origin, development, prevention and mitigation of dust explosions in the process industries. It offers an … This work is a comprehensive account of the existing practical and theoretical knowledge of the origin, development, prevention and mitigation of dust explosions in the process industries. It offers an up-to-date evaluation of prevalent activities, testing methods, design measures and safe operating techniques in a detailed and comprehensive critique of all the significant phases relating to the hazard and control of a dust explosion. This should be a useful reference work for design, production, maintenance and safety engineers in the process industries, safety consultants and students.

Continuous Spin Detonations

2006-11-01

Ф. А. Быковский , С. А. Ждан , Е. Ф. Ведерников

Results on controlled continuous spin detonation of various fuels in liquid-propellant rocket motors and ramjet combustors are reported. Schemes of chambers, combustion in transverse detonation waves, and typical photographic records … Results on controlled continuous spin detonation of various fuels in liquid-propellant rocket motors and ramjet combustors are reported. Schemes of chambers, combustion in transverse detonation waves, and typical photographic records of transverse detonation waves are given. The flow structure, existence conditions, and basic properties of continuous detonation are considered. An analysis of physical, chemical, and geometric parameters determining spin detonation is presented. Results of studying continuous spin detonation of C 2 H 2 + air and H 2 + air mixtures in an annular ducted chamber 30.6 cm in diameter are reported. The range of existence of continuous spin detonation in fuel-air mixtures is determined as a function of the governing parameters. In the case of high-quality mixing, the transverse detonation wave velocity and structure are extremely stable in a wide range of the ratios of propellant components and in the examined range of pressures in the chamber.

Two-phase modeling of deflagration-to-detonation transition in granular materials: Reduced equations

2001-10-01

A. K. Kapila , Ralph Menikoff , John B. Bdzil +2 more

Of the two-phase mixture models used to study deflagration-to-detonation transition in granular explosives, the Baer–Nunziato model is the most highly developed. It allows for unequal phase velocities and phase pressures, … Of the two-phase mixture models used to study deflagration-to-detonation transition in granular explosives, the Baer–Nunziato model is the most highly developed. It allows for unequal phase velocities and phase pressures, and includes source terms for drag and compaction that strive to erase velocity and pressure disequilibria. Since typical time scales associated with the equilibrating processes are small, source terms are stiff. This stiffness motivates the present work where we derive two reduced models in sequence, one with a single velocity and the other with both a single velocity and a single pressure. These reductions constitute outer solutions in the sense of matched asymptotic expansions, with the corresponding inner layers being just the partly dispersed shocks of the full model. The reduced models are hyperbolic and are mechanically as well as thermodynamically consistent with the parent model. However, they cannot be expressed in conservation form and hence require a regularization in order to fully specify the jump conditions across shock waves. Analysis of the inner layers of the full model provides one such regularization [Kapila et al., Phys. Fluids 9, 3885 (1997)], although other choices are also possible. Dissipation associated with degrees of freedom that have been eliminated is restricted to the thin layers and is accounted for by the jump conditions.

Gas explosion handbook

1997-01-01

Dag Bjerketvedt , Jan Roar Bakke , Kees van Wingerden

Electrothermal atomization—the way toward absolute methods of atomic absorption analysis

1978-01-01

Б. В. Львов

Ignition processes in hydrogenoxygen mixtures

1988-10-01

Ulrich Maas , J. Warnatz

Rotating Detonation Wave Propulsion: Experimental Challenges, Modeling, and Engine Concepts

2014-07-08

Frank Lu , Eric Braun

Thermodynamic Cycle Analysis of Pulse Detonation Engines

2002-01-01

William H. Heiser , David T. Pratt

Pulse detonation engines (PDEs) are currently attracting considerable research and development attention because they promise performance improvements over existing airbreathing propulsion devices. Because of their inherently unsteady behavior, it has … Pulse detonation engines (PDEs) are currently attracting considerable research and development attention because they promise performance improvements over existing airbreathing propulsion devices. Because of their inherently unsteady behavior, it has been difficult to conveniently classify and evaluate them relative to their steady-state counterparts. Consequently, most PDE studies employ unsteady gasdynamic calculations to determine the instantaneous pressures and forces acting on the surfaces of the device and integrate them over a cycle to determine thrust performance. A classical, closed thermodynamic cycle analysis of the PDE that is independent of time is presented. The most important result is the thermal efficiency of the PDE cycle, or the fraction of the heating value of the fuel that is converted to work that can be used to produce thrust. The cycle thermal efficiency is then used to find all of the traditional propulsion performance measures. The benefits of this approach are 1) that the fundamental processes incorporated in PDEs are clarified; 2) that direct, quantitative comparisons with other cycles (e.g., Brayton or Humphrey) are easily made; 3) that the influence of the entire ranges of the main parameters that influence PDE performance are easily explored; 4) that the ideal or upper limit of PDE performance capability is quantitatively established; and 5) that this analysis provides a basic building block for more complex PDE cycles. A comparison of cycle performance is made for ideal and real PDE, Brayton, and Humphrey cycles, utilizing realistic component loss models. The results show that the real PDE cycle has better performance than the real Brayton cycle only for flight Mach numbers less than about 3, or cycle static temperature ratios less than about 3. For flight Mach numbers greater than 3, the real Brayton cycle has better performance, and the real Humphrey cycle is an overoptimistic (and unnecessary) surrogate for the real PDE cycle.

Dynamic Parameters of Gaseous Detonations

1984-01-01

J H S Lee

The field of fluid mechanics is rapidly advancing, driven by unprecedented volumes of data from experiments, field measurements, and large-scale simulations at multiple spatiotemporal scales. Machine learning (ML) offers a … The field of fluid mechanics is rapidly advancing, driven by unprecedented volumes of data from experiments, field measurements, and large-scale simulations at multiple spatiotemporal scales. Machine learning (ML) offers a wealth of techniques to extract ...Read More

Recent Developments in the Research on Pulse Detonation Engines

2003-02-01

K. Kailasanath

Introduction I Nprinciple,detonationsare an extremelyef cientmeans of combustinga fuel-oxidizermixture and releasing its chemical energy content. During the past 60 years or so, there have been numerous researcheffortsat harnessingthepotentialof detonationsfor propulsion … Introduction I Nprinciple,detonationsare an extremelyef cientmeans of combustinga fuel-oxidizermixture and releasing its chemical energy content. During the past 60 years or so, there have been numerous researcheffortsat harnessingthepotentialof detonationsfor propulsion applications.1 There is a renewed interest lately on intermittent or pulsed detonations engines. Eidelman et al. and Eidelman and Grossmann3 have reviewed some of the initial research as well as work done in the late 1980s on pulse detonation engines (PDEs). The basic theory, design concepts, and the work in the early 1990s related to pulse detonationengines have been discussedby Bussing and Pappas.4 The focus of a more recent review5 is on performance estimates fromvarious experimental, theoreticaland computational studies. More recently, work related to nozzles for PDEs has been discussed. Other reviews7i9 discussing the objectives and accomplishments of various programs are also available.The objective of this paper is to update the previousreviews, focusingon themore recent developmentsin the researchon PDEs. The review is restricted toworkopenlyavailablein the literaturebut includesongoingefforts around the world. Currently, there are several programs sponsored by Of ce of Naval Research (ONR), U.S. Air Force, NASA, Defense Advanced Research Projects Agency, and other agencies in the United States as well as several parallel efforts in Belarus, Canada, France, Japan, Russia, Sweden, and other countries.The results from some of these programs are just beginning to be published.A summary of recent progress and the various organizationsand people involved in PDE research in Japan has been presented.9 Reports of the basic PDE research sponsoredby ONR are available in the proceedingsof a recurringannualmeeting(forexample, seeRef. 10).Recentwork conducted outside the United States has been reported at international meetings on detonations such as those held in Seattle11 (for more information, see http://www.engr.washington.edu/epp/icders/) and Moscow.12 Although an attempt is made to cover a broad range of the reported research, the shear volume of papers presented with PDEs in the title make it impractical to be exhaustive. Rather than providing a chronologicalreport, an attempt is made here to discuss the recent progress in terms of broad topic areas. The key issues that need to be resolved have been addressed in a number of papers (e.g., Refs. 13 and 14). The speci c order in which to discuss the various topics was determined by considering the schematic of an idealized, laboratory pulse detonation engine shown in Fig. 1. This idealizedengine is representativeof the device

Flow reactor studies and kinetic modeling of the H2/O2 reaction

1999-01-01

Mark A. Mueller , T. J. Kim , Richard A. Yetter +1 more

Profile measurements of the H2/O2 reaction have been obtained using a variable pressure flow reactor over pressure and temperature ranges of 0.3–15.7 atm and 850–1040 K, respectively. These data span … Profile measurements of the H2/O2 reaction have been obtained using a variable pressure flow reactor over pressure and temperature ranges of 0.3–15.7 atm and 850–1040 K, respectively. These data span the explosion limit behavior of the system and place significant emphasis on HO2 and H2O2 kinetics. The explosion limits of dilute H2/O2/N2 mixtures extend to higher pressures and temperatures than those previously observed for undiluted H2/O2 mixtures. In addition, the explosion limit data exhibit a marked transition to an extended second limit which runs parallel to the second limit criteria calculated by assuming HO2 formation to be terminating. The experimental data and modeling results show that the extended second limit remains an important boundary in H2/O2 kinetics. Near this limit, small increases in pressure can result in more than a two order of magnitude reduction in reaction rate. At conditions above the extended second limit, the reaction is characterized by an overall activation energy much higher than in the chain explosive regime. The overall data set, consisting primarily of experimentally measured profiles of H2, O2, H2O, and temperature, further expand the data base used for comprehensive mechanism development for the H2/O2 and CO/H2O/O2 systems. Several rate constants recommended in an earlier reaction mechanism have been modified using recently published rate constant data for H + O2 (+ N2) = HO2 (+ N2), HO2 + OH = H2O + O2, and HO2 + HO2 = H2O2 + O2. When these new rate constants are incorporated into the reaction mechanism, model predictions are in very good agreement with the experimental data. ©1999 John Wiley & Sons, Inc. Int J Chem Kinet 31: 113–125, 1999

Explosion hazards and evaluation

1984-01-01

David Rasbash

Mathematical theory of combustion and explosion

1983-01-01

P. A. Urtiew

25. The Oxidation of Nitrogen in Combustion and Explosions

1992-12-31

Hydrogen storage and delivery: Review of the state of the art technologies and risk and reliability analysis

2019-03-28

Ramin Moradi , Katrina M. Groth

Detonative propulsion

2012-11-27

P. Wolański

Combustion, Flames and Explosions of Gases

1987-01-01

Influence of Opening Ratio on the Formation of Tulip and Distorted Tulip Flames in Tubes

2025-06-25

Wei Mei , Min Li , Huahua Xiao | Combustion Science and Technology

Non-uniform methane/hydrogen explosions: Flame propagation and overpressure dynamics in confined vessels

2025-06-24

Lei Pang , Z. Wang , Jiqing Liu +4 more | International Journal of Hydrogen Energy

Cellular Dynamics of Helium-rich Detonation on Sub-Chandrasekhar Mass White Dwarf

2025-06-24

Kazuya Iwata , Keiichi Maeda | The Astrophysical Journal

Abstract In previous hydrodynamic studies on detonation in the context of Type Ia supernovae (SNe Ia), consideration of cellular structures has been limited in the evaluation of a criterion in … Abstract In previous hydrodynamic studies on detonation in the context of Type Ia supernovae (SNe Ia), consideration of cellular structures has been limited in the evaluation of a criterion in initiation, propagation, quenching, and the resolution requirement of detonation, whereas it is quite common to consider cell sizes in the discussion on terrestrial detonation in chemically reactive systems. In our recent study, the terrestrial cell-based theories, which incorporate the cell-size data acquired in two-dimensional simulations of helium detonation in the double-detonation model, were demonstrated to be powerful diagnostics in reproducing the thresholds in the initiation and quenching provided by previous studies. In the present study, two-dimensional simulation results of the cellular detonation in the base of a white dwarf's (WD) envelope are described in detail, in terms of the dynamic wave morphology and chemical abundance structure. The cellular structure is observed at a range of upstream density and envelope composition explored in the present work. C/O contamination by the WD's core material reduces the cell width rapidly, as accelerated by the α -capture reaction. It is also indicated that nickel production could be significantly delayed for the C/O-rich composition. The small cell width requires the detonation structure to be resolved in full-star simulations of SNe Ia, which could raise concerns about the robustness of the outcomes of some numerical simulations in terms of the success and failure of detonation. This issue may be overcome by subgrid modeling that incorporates the cellular dynamics acquired in resolved simulations.

The Influence Mechanism of Multiple-Factor Coupling Disturbance on the Detonation Wave Under Unsteady Supersonic Flow

2025-06-23

Jian Dai , Liu Jindian , Fanchao Kong | Combustion Science and Technology

Numerical Simulation Study on Coal Dust Ignition Induced by Irregular High-Temperature Heat Source

2025-06-23

Xurui Chen | Combustion Science and Technology

Preparation of phosphogypsum-based explosion suppressant to reduce the severity of dust explosions

2025-06-23

Qingwu Zhang , Xun Zou , Jianpeng Zhang +5 more | Advanced Powder Technology

Experimental study of hydrogen release self-ignition at different CH4 ratios

2025-06-21

Hui Qi , Zhenmin Luo , Shangyong Zhou +5 more | Fuel

Study on the Flame Propagation Characteristics of Coal Dust Explosions in Soaked and Air-Dried Conditions

2025-06-21

Jiahui Song , Ke Gao , Yinhui Wang +1 more | ACS Omega

Numerical characterization of post-detonation reshock driven mixing in explosions

2025-06-20

NULL AUTHOR_ID | Physical Review Fluids

Numerical simulation of explosion characteristics of premixed stoichiometric hydrogen/air in low pressure environment

2025-06-19

Baiwei Lei , Zejun Wu , X. Li | International Journal of Hydrogen Energy

Kinetic modelling and reactivity of liquid nitromethane under detonation conditions

2025-06-19

Teng Zhang , Lang Chen , Kun Yang +6 more | Communications Chemistry

Liquid nitromethane (NM) may undergo detonation under accidental stimuli, making kinetic modeling crucial for assessing the safety risks associated with its detonation. This study employs first-principles molecular dynamics to investigate … Liquid nitromethane (NM) may undergo detonation under accidental stimuli, making kinetic modeling crucial for assessing the safety risks associated with its detonation. This study employs first-principles molecular dynamics to investigate chemical behavior of nitromethane under high temperature (>2000 K) and pressure (>1 GPa) conditions, revealing five previously unidentified intermediates (CH3NO2H, CH2NO2H, CH2NOH, CH2ONO2, NOCH2NO2) and establishing a nitromethane chemical kinetic model which include 543 elementary reactions and 79 species, which is successfully applied in the prediction of nitromethane detonation characteristics. The calculated detonation pressure (13.5 GPa) and reaction zone time (46 ns) are in agreement with the experimental values (11.5-12.0 GPa; 50-53 ns). We also uncover the delayed response mechanism in pure nitromethane detonation. The major pollutants, many CO (34.8%), and small amount of NH3 (1.7%), HCN (1.0%), etc. in nitromethane detonation products are found. These findings advance the fundamental understanding of nitromethane's detonation reaction kinetics.

Analysis of the Flame-Arresting Performance of Pipeline Flame Arresters with Solid Particle Deposition

2025-06-19

Qian Huang , Jiangtao Xiao , Rui Quan Liao +3 more | Processes

In gas transmission stations, flame arrestors are typically installed in pipelines and venting systems to prevent the flames resulting from accidental ignition or deflagration of combustible gases during transmission from … In gas transmission stations, flame arrestors are typically installed in pipelines and venting systems to prevent the flames resulting from accidental ignition or deflagration of combustible gases during transmission from propagating through the pipelines. During actual operation, the presence of solid particulates in the gas compromises the flame-arresting efficacy and increases the failure rate of current pipeline flame arrestors. This study employs an integrated approach combining theoretical analysis and numerical simulation to establish a numerical model for flame arrestors that accounts for solid particle deposition effects. The model reveals the distribution characteristics of velocity fields, pressure fields, gas phase volumetric concentration fields, and solid deposition rate fields within pipeline flame arrestors. It systematically investigates the influence mechanisms of porosity, flame arrestor core thickness, inlet flame velocity, arrestor length, particle size, particle concentration on pressure drop, flame arrestment velocity, and deposition rate. These findings provide theoretical support for optimizing flame arrestor structural design and reducing operational failure rates.

Large Eddy Simulations on the Diffusion Features of the Cold-Vented Natural Gas Containing Sulfur

2025-06-19

Xu Sun , Meijiao Song , Sen Dong +4 more | Processes

For cold venting processes frequently employed in oil and gas fields, precisely predicting the instantaneous diffusion process of the vented explosive and/or toxic gases is of great importance, which cannot … For cold venting processes frequently employed in oil and gas fields, precisely predicting the instantaneous diffusion process of the vented explosive and/or toxic gases is of great importance, which cannot be captured by the Reynolds-averaged Navier–Stokes (RANS) method. In this paper, the large eddy simulation (LES) method is introduced for gas diffusion in an open space, and the diffusion characteristics of the sulfur-containing natural gas in the cold venting process is analyzed numerically. Firstly, a LES solution procedure of compressible gas diffusion is proposed based on the ANSYS Fluent 2022, and the numerical solution is verified using benchmark experiments. Subsequently, a computational model of the sulfur-containing natural gas diffusion process under the influence of a wind field is established, and the effects of wind speed, sulfur content, the venting rate and a downstream obstacle on the natural gas diffusion process are analyzed in detail. The results show that the proposed LES with the DSM sub-grid model is able to capture the transient diffusion process of heavy and light gases released in turbulent wind flow; the ratio between the venting rate and wind speed has a decisive influence on the gas diffusion process: a large venting rate increases the vertical diffusion distance and makes the gas cloud fluctuate more, while a large wind speed decreases the vertical width and stabilizes the gas cloud; for an obstacle located closely downstream, the venting pipe makes the vented gas gather on the windward side and move toward the ground, increasing the risk of ignition and poisoning near the ground. The LES solution procedure provides a more powerful tool for simulating the cold venting process of natural gas, and the results obtained could provide a theoretical basis for the safety evaluation and process optimization of sulfur-containing natural gas venting.

ANNUAL ACCIDENT PROBABILITIES IN BUILDING STRUCTURES CAUSED BY EXTERNAL EXPLOSIONS

2025-06-19

Toshiyuki Horiguchi , Takuji HAMAMOTO | AIJ Journal of Technology and Design

LES INVESTIGATION OF FILM COOLING IN ROTATING DETONATION COMBUSTORS

2025-06-19

Shreyas Ramanagar Sridhara , Antonio Andreini , Marc D. Polanka +1 more | Journal of Turbomachinery

Abstract High-power density combustors like Rotating Detonation Combustors (RDC) offer significant benefits. However, they must overcome many challenges to be integrated into a gas turbine. Cooling the RDC is one … Abstract High-power density combustors like Rotating Detonation Combustors (RDC) offer significant benefits. However, they must overcome many challenges to be integrated into a gas turbine. Cooling the RDC is one of the most significant, due to the high heat loads generated by the combustion process. Preliminary analysis of the required cooling system has shown that cold-side convective cooling is insufficient to cool combustor walls unless a protective barrier is applied to the hot side surface. Therefore, this work explores the feasibility of film cooling a RDC. A high-fidelity LES investigation was employed due to the uniqueness of this problem. Namely, it was expected that the detonation wave and the downstream oblique shock wave would have a significant impact on the flow exiting cooling holes for this type of combustor. This investigation represents the first attempt to integrate a full coverage film cooling scheme in a RDC. The results showed there is a period when each hole is effectively ‘blocked’, and coolant does not flow out of the hole. As the detonation wave passes, the film is able to recover and reform along the outer wall of the RDC. This process occurs at the detonation frequency of 7.5 kHz creating an unsteady, periodic flow behavior. Overall, the average gas temperature near the wall shows a significant reduction with the use of film cooling. These early results suggest that film cooling can be applied in an RDC flowfield.

The laminar burning velocity of hybrid iron-methane-air flames

2025-06-19

M.R. Hulsbos , R.T.E. Hermanns , R.J.M. Bastiaans +1 more | Combustion and Flame

Numerical simulation of cryogenic compressed hydrogen horizontal jet flame

2025-06-19

Xiandong Wang , Xinyu Lv , Tao Qiu | Journal of Energy Storage

Experimental study on high-frequency nSDBD assist ignition of ammonia/air mixture

2025-06-18

Yong Xiong , Jie Tian , Yong Cheng +1 more | Energy

Experimental study on the effect of coal dust in ammonia-hydrogen-air premixed gas duct-vented explosions

2025-06-18

Quan Wang , Yaoyong Yang , Wenyan Zhu +4 more | International Journal of Hydrogen Energy

Effect of turbine blades on rotating detonation wave propagation characteristics

2025-06-18

Chengming Zhang , Zhiyong Lin , Qin Shun | Proceedings of the Institution of Mechanical Engineers Part G Journal of Aerospace Engineering

This study investigated the impact of turbine blades on the rotating detonation combustion process and analyzes the interaction mechanisms between detonation-induced oblique shock waves and the turbine blades. The results … This study investigated the impact of turbine blades on the rotating detonation combustion process and analyzes the interaction mechanisms between detonation-induced oblique shock waves and the turbine blades. The results revealed that oblique shock waves induce multiple reflected shock waves within the blade passageways, leading to boundary layer separation and vortex flow on the blade surfaces. This phenomenon leads to a total pressure loss in turbine flow reaching 13%, compared to 8.3% with steady deflagration combustion. The influence of turbines on detonation combustion revealed that turbine rotor blades impede flow within the combustor, resulting in elevated the combustor pressure and detonation wave pressure, while the propagation speed of detonation waves remains unaffected. At low rotational speeds, ineffective fuel-air premixing leads to unstable detonation, while higher speeds stabilize the process. These findings advance understanding of detonation-turbine coupling and provide a basis for optimizing turbine blade design in rotating detonation engines.

Simulation Experimental Study on Evolution Law of Cumulative Damage in Coal under Shocks by Multiple High Pressure Air Blasting

2025-06-18

Shaoyang Yan , Fuqiang Gao , Bo Sun +4 more | ACS Omega

Experimental study on the influence of three typical surfactants on the explosion characteristics of coal dust clouds

2025-06-17

Lingfeng Wang , Zhengdong Liu , Jinglin Zhang +5 more | Journal of Loss Prevention in the Process Industries

Numerical Study on the Effect of Shape, Stagger, Separation Distance, and Number of Obstacles on Methane-Air Flame Acceleration in Partially Confined Geometry

2025-06-17

Ayushi Mishra , Krishnakant Agrawal , Mayank Kumar | Flow Turbulence and Combustion

Integrated experimental-computational approach to estimate TNT equivalence of hydrogen vessel bursts

2025-06-17

Sangyoung Han , Seung‐Wook Baek , Youngjoon Jeon +2 more | International Journal of Hydrogen Energy

Effects of cryogenic temperature on propagation of hydrogen-air rotating detonation waves

2025-06-17

Zhaoxin Ren , Jie Lü , Wulf G. Dettmer | Fuel

Effect of Hydrogen-Enriched Syngas and Nitrogen Dilution on Ammonia Deflagration Characteristics at Moderate Pressure

2025-06-17

Minh Tien Nguyen , Bùi Văn Ga , Hong-Quan Do +4 more | ACS Omega

The Risk to the Undersea Engineering Ecosystem of Systems: Understanding Implosion in Confined Environments

2025-06-17

Craig Tilton , Arun Shukla | Journal of Marine Science and Engineering

As humans continue to develop the undersea engineering ecosystem of systems, the consequences of catastrophic events must continue to be investigated and understood. Almost every undersea pressure vessel, from pipelines … As humans continue to develop the undersea engineering ecosystem of systems, the consequences of catastrophic events must continue to be investigated and understood. Almost every undersea pressure vessel, from pipelines to sensors to unmanned vehicles, has the potential to experience a catastrophic collapse, known as an implosion. This collapse can be caused by hydrostatic pressure or any combination of external loadings from natural disasters to pressure waves imparted by other implosion or explosion events. During an implosion, high-magnitude pressure waves can be emitted, which can cause adverse effects on surrounding structures, marine life, or even people. The imploding structure, known as an implodable volume, can be in a free-field or confined environment. Confined implosion is characterized by a surrounding structure that significantly affects the flow of fluid around the implodable volume. Often, the confining structure is cylindrical, with one closed end and one open end. This work seeks to understand the effect of fluid flow restriction on the physics of implosion inside a confining tube. To do so, a comprehensive experimental study is conducted using a unique experimental facility. Thin-walled aluminum cylinders are collapsed inside a confining tube within a large pressure vessel. High-speed photography and 3D Digital Image Correlation are used to gather structural displacement and velocities during the event while an array of dynamic pressure sensors capture the pressure data inside the confining tube. The results of this work show that by changing the size of the open end, referred to as the flow area ratio, there can be a significant effect on the structural deformations and implosion severity. It also reveals that only certain configurations of holes at the open end of the tube play a role in the dynamic pressure pulse measured at the closed end of the tube. By understanding the consequences of an implosion, designers can make decisions about where these pressure vessels should be in relation to other pressure vessels, critical infrastructure, marine life, or people. In the same way that engineers design for earthquakes and analyze the impact their structures have on the environment around them, contributors to the undersea engineering ecosystem should design with implosion in mind.

Steam-aerosol interaction experiments: Measurement of aerosol and liquid droplet size distributions

2025-06-17

Manish Joshi , Mariam Mariam , Arshad Khan +4 more | Progress in Nuclear Energy

The Evaluation of Methane Gas Explosion Risk in Confined Spaces – A Case Study in the Ship Building Industry

2025-06-16

Ferdi Çalık | International Journal of Advances in Engineering and Pure Sciences

Hydrocarbon gas explosions such as methane gas in confined spaces represent a significant hazard across various industries, particularly mining, oil and gas extraction, and oxy-cutting processes. The risks associated with … Hydrocarbon gas explosions such as methane gas in confined spaces represent a significant hazard across various industries, particularly mining, oil and gas extraction, and oxy-cutting processes. The risks associated with methane accumulation are exacerbated by the unique characteristics of confined spaces, where gas concentrations can reach explosive levels. The explosive potential of methane is primarily influenced by its concentration in the air. Understanding the conditions under which methane becomes hazardous is crucial for developing effective safety protocols and mitigation strategies. This study is based on a truth gas leak near-miss incident in the shipyard ship building department. Before this study, there were many records of gas leaks due to hose and torch connection points and hose damage in oxy-fuel cutting operations. During the confined spaces (ballast, cargo, service, settling tanks etc.) gas free measurements on April 8, 2024, we detected a methane gas leak reaching explosive concentrations originating from a damaged welding hose. In this study, the question of what would happen if this explosive atmosphere in the confined space exploded under optimum conditions was answered. According to the results of the study, the explosive methane gas concentration in a 169 m3 confined space (ballast tank) was approximately 10 kg methane gas mass, and the methane gas leak of 80 % of the hose cross-section diameter reached an explosive concentration within 15 minutes. The amount of 10 kg methane gas leaking into the 169 m3 confined space was equivalent to the 95000 ppm (9.5 % v/v) methane gas concentration required to provide optimum explosion conditions. After an explosion caused by 10 kg of methane gas in the ballast tank (169 m3), a worker standing 1 m away will be exposed to 1523 kPa of overpressure. 10 kg methane gas used for the explosion scenario represents the stoichiometric fuel/air mixture (95000 ppm). When the evaluation is made by taking into account the 1 s positive phase duration, the mortality rate due to lung damage, which is one of the organs most exposed to air, means that a person standing 1 m away is exposed to 1523 kPa overpressure and the probability of death (Pr) is estimated as 93%. This result may have more dramatic consequence depending on the number of people in the ballast tank.

Experimental and Numerical Analysis of Sub‐Detonative Behaviors in Insensitive Energetic Materials Under Non‐shock Stimuli

2025-06-16

Wei Xian Lim , Danyang Liu , Hay Yee Serene Chan +1 more | Propellants Explosives Pyrotechnics

ABSTRACT Insensitive munitions are designed to enhance safety by resisting accidental detonation when exposed to mechanical or thermal threats, aiming to safeguard military personnel and equipment. This study investigates the … ABSTRACT Insensitive munitions are designed to enhance safety by resisting accidental detonation when exposed to mechanical or thermal threats, aiming to safeguard military personnel and equipment. This study investigates the mild responses of insensitive energetic materials, specifically burn‐to‐explosion behaviors under non‐shock stimuli. Burn‐to‐violent‐reaction (BVR) tests were conducted on a typical insensitive explosive, PBXN‐109, to collect data on ignition times, reaction responses, and burn pressures under a low ignition pressure of around 10 MPa, which are critical for developing numerical models for sub‐detonative phenomenon. This work adopts a propellant deflagration model calibrated with BVR experimental measurements to accurately predict long‐duration deflagration reactions lasting hundreds of milliseconds. Experimental results highlight the significance of gas pressurization and venting in controlling explosive damage propagation and ignition timing. The calibrated models, validated against experimental data, indicate that maximum deflagration response can be achieved under perfect confinement. This work advances the understanding of sub‐detonative phenomena. It presents a computational methodology for predicting and mitigating risks associated with energetic materials, addressing the critical need for comprehensive models that integrate experimental and numerical approaches to predict munitions' behavior under various conditions.

THE MONTE CARLO METHOD IN NON-HOMOGENEOUS MEDIA FOR EVALUATING THE RISK OF EXPLOSION IN TANKS

2025-06-14

TUDOR MICU , Dan D. Micu | REVUE ROUMAINE DES SCIENCES TECHNIQUES — SÉRIE ÉLECTROTECHNIQUE ET ÉNERGÉTIQUE

The paper presents an application of the Monte Carlo method to a model of a parallel-plane non-homogeneous medium corresponding to a parallelepiped tank. We derive the expressions for the primary … The paper presents an application of the Monte Carlo method to a model of a parallel-plane non-homogeneous medium corresponding to a parallelepiped tank. We derive the expressions for the primary and secondary statistical estimators. The network is considered rectangular, and the non-homogeneous media have the separation surface parallel to the coordinate axes. Based on these principles, we have calculated the electrostatic field at the air-gasoline separation surface and evaluated the risk of explosion based on the electric charge state of the gasoline.

Effects of concentration and spray pressure on TiH2 dust ignition and flame propagation

2025-06-14

Li Zhu , Juncheng Jiang , Song Lin +3 more | International Journal of Hydrogen Energy

Potential Fire Hazards for Liquid Hydrogen-Powered Aircraft Related to Cabin Safety

2025-06-14

Wahyu Cakra NUGRAHA , Taufiq Mulyanto , Jean‐François Petit | Langit Biru Jurnal Ilmiah Aviasi

Hydrogen is being considered as an alternative fuel for aircraft propulsion, due to its low emissions, especially liquid hydrogen. However, concerns about cabin safety in aircraft powered by liquid hydrogen … Hydrogen is being considered as an alternative fuel for aircraft propulsion, due to its low emissions, especially liquid hydrogen. However, concerns about cabin safety in aircraft powered by liquid hydrogen are substantial, requiring a comprehensive understanding and effective countermeasures in operation. Analysing the fire potential due to hydrogen leakage, is essential for a deeper understanding of the safety challenges associated with hydrogen applications. This can be achieved through a comparative analysis between the utilisation of liquid hydrogen and traditional fuels in aircraft, using a document study approach. This research thoroughly investigated and evaluated the potential fire hazards of hydrogen with regards to cabin safety. The highly flammable and difficult-to-detect nature of hydrogen poses challenges in terms of fire safety, especially in the confined spaces of aircraft cabins. Therefore, it is critical to ensure that the safety level of liquid hydrogen remain at an acceptable standard when compared to conventional fuel.

Experimental study on the explosion inhibition of H2/CH4/air mixture using modified KHCO3

2025-06-13

Zhenmin Luo , Yuwei Wang , Yali Sun +4 more | International Journal of Hydrogen Energy

Response of non-premixed jet flames to blast waves

2025-06-13

Akhil Aravind , Gautham Vadlamudi , Saptarshi Basu | Journal of Fluid Mechanics

The work investigates the response dynamics of non-premixed jet flames to blast waves that are incident along the jet axis. In the present study, blast waves, generated using the wire-explosion … The work investigates the response dynamics of non-premixed jet flames to blast waves that are incident along the jet axis. In the present study, blast waves, generated using the wire-explosion technique, are forced to sweep across a non-premixed jet flame that is stabilised over a nozzle rim positioned at a distance of 264 mm from the source of the blast waves. The work spans a wide range of fuel-jet Reynolds numbers ( $Re$ ; ranging from 267 to 800) and incident blast-wave Mach numbers ( $M_{s,r}$ ; ranging from 1.025 to 1.075). The interaction imposes a characteristic flow field over the jet flame marked by a sharp discontinuity followed by a decaying profile and a delayed second spike. The second spike in the flow field profile corresponds to the induced flow that follows the blast front. While the response of the flame to the blast front was minimal, it was found to detach from the nozzle rim and lift off following the interaction with the induced flow. Subsequently, the lifted flame was found to reattach back at the nozzle or extinguish, contingent on the operating $Re$ and $M_{s,r}$ . Alongside flame lift-off, flame-tip flickering was aggravated under the influence of the induced flow. A simplified theoretical model extending the vorticity transport equation was developed to estimate the change in flickering time scales and length scales owing to the interaction with the induced flow. The observed experimental trends were further compared against theoretical predictions from the model.

Analytical Observations of Blast Wave Behavior for Generalized Chaplygin Gas

2025-06-13

Dhanpal Singh , Ekta Jain | Heat Transfer

ABSTRACT The present article utilizes an analytical method to investigate the problem of propagation of blast waves in a generalized Chaplygin gas. An analytical solution demonstrating time‐space dependency considering gas‐dynamical … ABSTRACT The present article utilizes an analytical method to investigate the problem of propagation of blast waves in a generalized Chaplygin gas. An analytical solution demonstrating time‐space dependency considering gas‐dynamical flow parameters has been obtained. Further, the evolution of the total energy during propagation of the blast wave is discussed. By providing both theoretical insights and empirical relevance, our findings offer valuable contributions to understanding exotic fluids and their role in cosmic phenomena.

Thermal Compensation of Piezoresistive Sensors to Facilitate Absolute Pressure Measurements in Rotating Detonation Engines

2025-06-13

Robert S. Miller , Ajay K. Agrawal , John P. Hilton | Journal of Propulsion and Power

A methodology to account for thermal drift in piezoresistive (PR) pressure sensors is presented and applied to a rotating detonation engine (RDE). First, a modified Wheatstone bridge with a fifth-wire … A methodology to account for thermal drift in piezoresistive (PR) pressure sensors is presented and applied to a rotating detonation engine (RDE). First, a modified Wheatstone bridge with a fifth-wire arrangement is introduced to determine the sensor temperature in real time. Second, sensor calibration is performed to account for sensor temperature effects on zero-offset voltage and sensor sensitivity. Sensor response at thermally steady and transient conditions is examined at varying initial heat flux inputs simulated by dry (air) and wet (molten salt bath) environments to demonstrate that a nonisothermal sensor can introduce significant errors. Finally, the calibrated sensor is installed in an annular RDE in a recessed probe configuration to measure the absolute wall pressure split into time-varying and steady components. Results show that the time-varying pressure measurements obtained by PR and piezoelectric probes agree spectrally, but the former detected higher pressure peaks because of its smaller sensing diameter. Thermal compensation vastly improved the accuracy of absolute pressure measurements, but further improvements are necessary to minimize thermally induced errors associated with the zero-offset voltage.

Research on the flow characteristics and spontaneous ignition mechanism of high-pressure hydrogen in semi-closed T-tube

2025-06-13

Xuhai Pan , Yuchu Chen , Langqing Lu +4 more | International Journal of Hydrogen Energy

Analysis of the impact of weather conditions on hazard zones considering a specific configuration of a hydrogen refuelling station

2025-06-13

Krzysztof Rusin , Andrzej Rusin , Katarzyna Stolecka +1 more | Energy

Investigating the effect of random packing on flame quenching and explosion pressure suppression

2025-06-13

Shoutao Ma , Ran Shang , Hongwei Zhu +2 more | Journal of Loss Prevention in the Process Industries

Numerical investigation of unconfined hydrogen explosions using an embedded large eddy simulation (ELES) approach with detailed chemical reaction mechanisms

2025-06-13

W. Senarathna , Damith Mohotti , Kasun Wijesooriya +4 more | International Journal of Hydrogen Energy

Experimental study of average and high-frequency wall heat flux characteristics in a compact rotating detonation engine

2025-06-12

Z. John , Yuechen Hou , Xiangjun Zhang +3 more | Aerospace Science and Technology

Design and Investigation of Nanosilicon Powder Preparation Using an Electro‐Explosion Method

2025-06-12

P.P. Zhang , Chenxu Li , Qipeng Yu +1 more | physica status solidi (a)

Electroburst technology is widely used in the field of metal processing for various applications, including the preparation of ultrafine powders and material surface coatings, but is less common in the … Electroburst technology is widely used in the field of metal processing for various applications, including the preparation of ultrafine powders and material surface coatings, but is less common in the field of non‐metallic applications. In this study, nanosilicon powder is prepared using in‐house designed electroburst equipment. Using micron‐sized industrial‐grade silicon powder as the raw material, the electroburst equipment is employed to apply a high voltage of 16 kV in an argon atmosphere across both ends of a carrier bar loaded with the powder, which is broken into nanosilicon powder under the effect of Joule heat and shock waves. The prepared nanosilicon powder is characterized via X‐ray diffraction, scanning electron microscopy, energy‐dispersive X‐ray spectroscopy, transmission electron microscopy (TEM), and dynamic light scattering, and the results show that it comprised silicon monomers. The overall particle size of the nanosilicon samples is more uniform and significantly smaller compared to that of the raw material, with an average particle size of 89 nm while retaining the polycrystalline structures at the nanoscale. Finally, the prepared nanosilicon powder is tested in a button cell assembly, and the results show that its discharge and charge capacities are 2360.4 and 1901.2 mAh g −1 , respectively. The proposed electroburst method offers a new approach to nanosilica powder preparation.

Causes of battery fires in railway vehicles and challenges of extinguishing

2025-06-12

Jakub Krejčí | Acta Polytechnica CTU Proceedings

The aim of this article is to introduce an issue that has not yet been addressed in our region – the fire hazards of BEMU units. The methodology of the … The aim of this article is to introduce an issue that has not yet been addressed in our region – the fire hazards of BEMU units. The methodology of the Fire Rescue Service of the Czech Republic vehicles was used to establish the basic procedure for extinguishing batteries in railway passenger coaches.