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Analysis of Plastic Deformation of Pipes Due to deflagration to detonation transition Using Static Equivalent Pressure

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JOURNAL OF PRESSURE VESSEL TECHNOLOGY-TRANSACTIONS OF THE ASME 2024年第3期146卷 031001-031001页

作者： Mueller, Matthias Bernhardi, Otto-Ernst Denecke, Jens Schildberg, Hans-Peter Schmidt, Juergen Hsch Karlsruhe Univ Appl Sci D-76133 Karlsruhe Germany CSE Ctr Safety Excellence CSE Inst D-76327 Pfinztal Germany BASF SE Safety Engn D-67056 Ludwigshafen Germany

Explosions of premixed gases with deflagration to detonation transition (DDT) are a risk in the process industry with potentially catastrophic consequences. Robust and simple design methods are required for industrial use. Such a simplified design method based on finite element analysis is proposed to model the dynamic behavior of pipes loaded by gas explosions of premixed gases including DDT. The focus is on so-called long pipes, where the DDT is not affected by reflections at blind flanges. First, it is reviewed how the pressure load of the gas explosion and the resulting material behavior has been modeled in previous publications. The analytical equations are then extended for describing the pressure load as a function of time and location by considering the leading compression wave as it affects the pressure load of the overdriven detonation. The extended analytical equations are parameterized using Chapman-Jouguet conditions and experimental results from publications for both static equivalent pressure and the location of the DDT. To describe the plastic material behavior at high strain rates, the well-known Johnson-Cook plasticity model is used. The material parameters of the model are derived from simple experiments, which are available in an industrial environment. The comparison of a finite element simulation with experimental data shows that the concept of equivalent static pressure can be extended to an finite element analysis, which in the future will allow the sizing of complete pipe systems including tees, bends, and flanges while considering plastic deformation.

关键词： gas explosion deflagration to detonation transition DDT premixed gases plasticity pipe sizing finite element modeling

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Study of a qualitative model for combustion waves: Flames, detonations, and deflagration-to-detonation transition

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COMPUTERS & FLUIDS 2024年 273卷

作者： Goldin, Andrei Yu. Magomedov, Shamil M. Faria, Luiz M. Kasimov, Aslan R. Skolkovo Inst Sci & Technol Bolshoy Blvd 30Bldg 1 Moscow 121205 Russia Inst Polytech Paris CNRS POEMS INRIAENSTA Paris Palaiseau France Sechenov Univ Inst Comp Sci & Math Modeling 8-2 Trubetskaya St Moscow 119991 Russia

We analyze a simplified one-dimensional model of combustion that includes the effects of compressibility, diffusion, heat conduction, viscosity, and exothermic heat release. Using numerical simulations, we show that the model predicts both detonation-like and deflagration-like traveling waves. Importantly, it also predicts spontaneous transition from deflagration to detonation in the problem of hot-spot ignition from a closed end of a channel.

关键词： detonation deflagration to detonation transition detonation analog Reactive Navier-Stokes equations

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Flame front dynamics, shape and structure on acceleration and deflagration-to-detonation transition

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ACTA ASTRONAUTICA 2023年 204卷 692-704页

作者： Krivosheyev, Pavel Novitski, Alexey Penyazkov, Oleg AV Luikov Heat & Mass Transfer Inst 15P Brovka Str Minsk 220072 BELARUS

Developing a new generation of rocket engines based on detonation principles needs methods which ensure stability of operation including the onset of detonation wave after mild ignition. This aspect is crucial for ensuring safety of such engines. In the present paper the transition processes associated with flame acceleration and the onset of a detonation mode are under investigation. High-speed flame front photography has been performed during the deflagration of a premixed gas mixture in a long smooth tube. The evolution of flame front structure and shape has been determined, starting from the moment of deflagration initiation and ending with the occurrence of a local explosion leading to the formation of a detonation wave. Four characteristic flame propagation stages have been identified: the initial flame acceleration stage, followed by the apparent velocity deceleration stage, followed by the nearly constant propagation velocity stage, and finally the second acceler-ation stage, during which detonation is formed. The changes in process dynamics with a change in the initial pressure have been demonstrated. The behavior of flame front at the early stage of acceleration has been identified. The experimental findings are compared with the theoretical models available in the literature. At the initial stage of the accelerated propagation of flame extended along the channel walls - until deceleration - the velocity of the leading tip of the front is effectively described by the exponential relationship proposed by C. Clanet and G. Searby (1996). The most interesting and poorly studied, in the authors' opinion, stage of the deflagration-to-detonation transition process, the intensive repeated acceleration stage, during which flame shape changes abruptly, has been described in detail. The laminar burning velocity of the stoichiometric ace-tylene-oxygen mixture diluted with either nitrogen or argon at a reduced initial pressure (8-21 kPa) has been identified.

关键词： Flame acceleration deflagration to detonation transition Flame shape Flame structure High-speed imaging

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Ozone and Plasma-assisted deflagration to detonation transition of Dimethyl Ether in a Microchannel

Ozone and Plasma-assisted Deflagration to Detonation Transit...

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AIAA Science and Technology Forum and Exposition (AIAA SciTech Forum)

作者： Vorenkamp, Madeline Murakami, Yuki Chen, Timothy Nickerson, Michaela Rousso, Aric Starikovskiy, Andrey Ju, Yiguang Princeton Univ Dept Mech & Aerosp Engn Mech & Aerosp Engn Princeton NJ 08544 USA Tohoku Univ Inst Fluid Sci 2-1-1 KatahiraAoba Ku Sendai Miyagi 9808577 Japan

ISBN: (数字)9781624106095

ISBN: (纸本)9781624106095

This study aimed to understand the plasma assisted low temperature ignition influence on detonation to deflagration transitions (DDT) in a microchannel at atmospheric pressure by using dimethyl ether (DME). At first, we examined the effect of ozone chemical sensitization on DDT. The kinetic effect of O radial addition via ozone dissociation on DDT for DME was investigated. In the second experiment, a dielectric barrier discharge is used for mixture pre-excitation to increase the chemical reactivity for fast DDT. Non-equilibrium plasma creates fast and slow heating of a mixture due to electronic excitation and vibration-rotation energy transfer. Moreover, it produces active species such as atomic oxygen and electronically excited nitrogen and oxygen molecules which can significantly enhance low temperature and high temperature oxidation of fuel and thus accelerate ignition processes dramatically. The effects of plasma generated active species and plasma fast and slow heating on DDT is investigated. The present experiments will provide insights to control engine knock and DDT in advanced engines.

关键词： deflagration to detonation transition Dielectric Barrier Discharge Energy Transfer Pulse detonation Engine Thermal Decomposition Combustion Chambers Power Generation Brayton Cycle Energy Conversion Efficiency Flow Characteristics

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The Physics of detonation Chemistry: A Radical Theory in Predicting the deflagration to detonation transition, Environmental and Supernova Explosions

The Physics of Detonation Chemistry: A Radical Theory in Pre...

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AIAA Propulsion and Energy Forum / IEEE Electric Aircraft Technologies Symposium (EATS)

作者： Kumar, V. R. Sanal Nichith, C. Vigneshwaran, S. Ajith, S. Sivabalan, M. Tharikaa, R. Sathyan, P. Vignesh, S. Vishnu, N. Sai, Hema N. Niyasdeen, Mohammed N. Sulthan, A. R. M. Roshan, V. B. Pavithra, M. Amrith, M. Thianesh, U. K. Anandmoorthi Mohan, E. Kumar, Pradeep P. Bharath, R. S. Oommen, Charlie Radhakrishnan, Pradeep Kumar Choudhary, Shiv Kumar Vigneshwaran, R. Surya, B. Kumar, Akshay N. Deviparameswari, K. Shankaran, Sai B. Asher, Prisha K. Aloy, Merrish A. Lohit, V Indian Space Res Org Trivandrum 695022 Kerala India Kumaraguru Coll Technol Int Res Grp Prop & Combust Coimbatore 641049 Tamil Nadu India Indian Inst Sci Aerosp Engn Bangalore 560012 Karnataka India GITAM Univ Div Cardiothorac & Vasc Surg Visakhapatnam 530045 Andhra Pradesh India All India Inst Med Sci Cardiothorac & Vasc Surg New Delhi 110608 India Kumaraguru Coll Technol Coimbatore 641049 Tamil Nadu India

ISBN: (数字)9781624106118

ISBN: (纸本)9781624106118

The theoretical finding of the Sanal flow choking [PMCID: PMC7267099] is a methodological advancement in predicting the deflagration-to-detonation-transition (DDT) in the real-world-fluid flows (continuum/non-continuum) with credibility. Herein, we provide a proof of the concept of the Sanal-flow-choking and streamtube-flow-choking [*** et al., Physics of Fluids 33, 036108 (2021);https://***/10.1063/5.0040440] causing DDT in wall-bounded and free-external flows. Once the streamlines compacted, the considerable pressure difference attains inside the streamtube and the flow gets accelerated to the constricted region for satisfying the continuity condition set by the conservation law of nature. If the shape of the streamtube in the internal/external flow is similar to the convergent-divergent (CD) duct the phenomenon of the Sanal flow choking and supersonic flow development occurs at a critical-total-to-static pressure ratio (CPR) in yocto to yotta scale systems and beyond, which leads to shock wave generation or detonation as the case may be. It has been reported that at the lower critical detonation or hemorrhage index, the CPR of the reacting flow and the critical blood-pressure-ratio (BPR) of the subjects (human being/animal) are unique functions of the heat-capacity-ratio (HCR) of the evolved gas in the CD duct [PMC7933821]. In silico results are presented herein, with the reacting and non-reacting flow simulation of an internal flow system, to establish the proof of the concept of the Sanal-flow-choking and streamtube-flow-choking causing shock-wave/detonation. Parametric analytical studies have been carried out with different oxidizer-fuel ratio, chamber pressure, geometric variables, and multiple-step combustion for examining the possibilities of detonation due to the Sanal flow choking and streamtube flow choking. In all the case studies we have noticed that the Sanal flow choking and/or streamtube-flow-choking occurs when the total-to-static press

关键词： Supernovae deflagration to detonation transition Choking Mach Number Flow Characteristics In Compressible Viscous Flows Shock Diamond Compressibility Effect Static Pressure Nanoelectromechanical Systems Non Reacting Flow

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Effect of Plasma-Enhanced Low-Temperature Chemistry on deflagration-to-detonation transition in a Microchannel

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AIAA JOURNAL 2023年第11期61卷 4821-4827页

作者： Vorenkamp, Madeline Steinmetz, Scott Mao, Xingqian Shi, Zhiyu Starikovskiy, Andrey Ju, Yiguang Kliewer, Christopher Princeton Univ Dept Mech & Aerosp Engn Princeton NJ 08544 USA Sandia Natl Labs Livermore CA 94550 USA

This study examines low-temperature chemistry (LTC) enhancement by nanosecond dielectric barrier discharge (ns-DBD) plasma on a dimethyl ether (DME)/oxygen (O-2)/argon (Ar) premixture for deflagration-to-detonation transition (DDT) in a microchannel. It is found that non-equilibrium plasma generates active species and kinetically accelerates LTC of DME and DDT. In situ laser diagnostics and computational modeling examine the influence of the ns-DBDs on the LTC of DME and DDT using formaldehyde (CH2O) laser-induced fluorescence (LIF) and high-speed imaging. Firstly, high-speed imaging in combination with LIF is used to trace the presence of LTC throughout the flame front propagation and DDT. Then, competition between plasma-enhanced LTC of ignition and reduced heat release rate of combustion due to plasma-assisted partial fuel oxidation is studied with LIF. Observations of plasma-enhanced LTC effects on DDT are interpreted with the aid of detailed kinetic simulations. The results show that an appropriate number of ns-DBDs enhances LTC of DME and increases CH2O formation and low-temperature ignition, accelerating DDT. Moreover, it is found that, with many ns-DBDs, CH2O concentration decreases, indicating that excessive discharges may accelerate fuel oxidation in the premixture, reducing heat release and weakening shock-ignition coupling, inhibiting DDT.

关键词： deflagration to detonation transition Laser Induced Fluorescence Computational Modeling Dielectric Barrier Discharge Non Equilibrium Plasmas Lasers and Laser Applications Ignition Systems Rotating detonation Engine Electric Field Strength Optical Properties

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Numerical simulation of the deflagration to detonation transition behavior in explosives based on the material point method

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COMBUSTION AND FLAME 2022年 238卷 111920-111920页

作者： Chen, Weidong Wu, Shibo Ma, Jingxin Liu, Lan Lu, Shengzhuo Harbin Engn Univ Coll Aerosp & Civil Engn Harbin 150001 Peoples R China Beijing Inst Struct & Environm Engn Beijing 100076 Peoples R China

The problem of the deflagration to detonation transition (DDT) in explosives has been concerned seriously for many years, but the existing numerical models have different defects. It is difficult for them to accurately and quantitatively describe the DDT process of explosives under complex conditions (such as different constraint conditions). On the basis of the material point method, the DDT numerical model of explosives under complex conditions is established by using the heat balance equation, EOS of JWL, EOS of Virial and Lee-Tarver equation in this paper. In the model, the combustion reaction and detonation reaction of explosives can be described, and the influence of constraint condition on the DDT process of explosives is considered. Meanwhile, DDT critical condition of explosives and the judgment method of the starting position of explosive detonation reaction are given. The model is used to simulate the DDT process of COM B explosive constrained by steel tube in this paper. The simulation results show that the stable detonation velocity is about 7700 m/s, the stable detonation pressure is about 0.325 Mbar, and the induced detonation distance is 30.2 cm. Analysis found that the detonation reaction of COM B explosive occurred in the incomplete combustion area. The simulation results are in agreement with the experimental results in literature, which verifies the correctness of the model proposed by this paper. (c) 2021 The Combustion Institute. Published by Elsevier Inc. All rights reserved.

关键词： deflagration to detonation transition Numerical simulation Critical condition Constraint condition Material point method

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deflagration to detonation transition assisted by equilibrium and non-equilibrium plasma

Deflagration to detonation transition assisted by equilibriu...

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AIAA Aviation Forum and Exposition

作者： Mahamud, Rajib Tropina, Albin A. Miles, Richard B. Texas A&M Univ Aerosp Dept College Stn TX 77840 USA

ISBN: (数字)9781624105890

ISBN: (纸本)9781624105890

We present a model and simulation results of plasma aided deflagration to detonation transition. We consider two ideal cases, when plasma was modeled as a source of radicals and as a joule heating source with the conductivity depending on time. The simulation results showed a decrease of the deflagration-detonation transition time and distance with injection of radicals, which was found to be more efficient than a thermal effect of plasma. We also observed changes in the detonation cell size and detonation velocities at the different orientation of the energy deposition by plasma.

关键词： deflagration to detonation transition Joule Heating Thermal Effects Velocity Profiles Nonequilibrium Plasmas Dielectric Barrier Discharge Implicit Euler Method Kinetic Energy Numerical Simulation Finite Volume Method

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Effects of Obstacles on deflagration-to-detonation transition in Linked Vessels

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COMBUSTION SCIENCE AND TECHNOLOGY 2022年第6期194卷 1265-1281页

作者： Yin, Zhonglin Wang, Zhirong Cao, Xingyan Zhen, Yaya Jiang, Kewei Ma, Shichang Gao, Wei Nanjing Tech Univ Jiangsu Key Lab Hazardous Chem Safety & Control Coll Safety Sci & Engn Nanjing 210009 Peoples R China Dalian Univ Technol Sch Chem Engn Dalian Peoples R China

order to study the characteristics and rules of deflagration to detonation transition (DDT) in linked vessels, two typical linked vessels were selected in this paper. The research was focused on the effects of pipe length, obstacle number, obstacle position and obstacle blockage ratio on DDT of methane air mixture in linked vessels. The experimental results showed that the pressure peak and the speed of flame propagation were enhanced by the obstacles. The precursory shock waves and the chemical reaction zone were coupled to propagate and caused the occurrence of DDT. When the obstacles were placed in the linked vessels, the distance of DDT occurrence moved forward. Moreover, with the increase of obstacle number, the induced distance of DDT was reduced. The induced distance of DDT was relatively short when the obstacle position was near the location of the explosion vessel.

关键词： deflagration to detonation transition obstacle number obstacle position blockage ratio linked vessels

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Unconfined Fast Flames deflagration-to-detonation transition

Unconfined Fast Flames Deflagration-to-Detonation Transition

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AIAA Science and Technology Forum and Exposition (AIAA SciTech)

作者： Hytovick, Rachel Chambers, Jessica Sosa, Jonathan Ahmed, Kareem Univ Cent Florida Prop & Energy Res Lab Mech & Aerosp Engn Orlando FL 32816 USA

ISBN: (数字)9781624105951

ISBN: (纸本)9781624105951

The present work explores the mechanisms behind unconfined deflagration-to-detonation transition (DDT). Evidence of unconfined DDT is shown when a flame is exposed to extremely high turbulence levels and rapidly accelerates to produce a spontaneous detonation wave in an unbounded area. This process is hypothesized to naturally occur in various phenomena such as interstellar combustion, Type Ia supernovae, and some hydrogen explosions. Until recently, these occurrences have only been successfully explored in computational simulations due to the difficulty of replicating the experimental conditions. To experimentally examine the mechanism of unconfined DDT, a premixed, hydrogen-air flame enters an unbounded area where it encounters a spherical gas consisting of hydrogen and oxygen. Shortly after, the shock-flame and soap bubble interact creating local flame acceleration and, in some cases, a local detonation. High speed schlieren is used to visualize the varying combustion regimes and compute the shock and flame velocities.

关键词： deflagration to detonation transition detonation Waves Supernovae Pulse detonation Engine Aerospace Engineering Solenoid Valves Shock Tube Energy Research Astrophysics Power Supplies

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