Detonation Velocity Research Articles

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.

A dynamic droplet breakup model for Eulerian-Lagrangian simulation of liquid-fueled detonation

This study proposes a dynamic model to reflect the physical image of the droplet breakup process in two-phase detonation flows. This breakup model is implemented in a two-phase detonation solver developed based on an open-source computational fluid dynamic platform, OpenFOAM, and compared with three prevalent models (TAB, PilchErdman, and ReitzKH-RT model) under different droplet diameters (30–70 μm) in one- and two-dimensional detonation problems. The simulating results show that the present breakup model well predicts experimentally determined detonation parameters such as detonation velocities and post-wave temperature. In addition, the present model has the advantage of being free of the KH breakup time parameter, which the ReitzKH-RT model needs to fit the experimental data. The one-dimensional detonation simulations indicate that different breakup models slightly impact the detonation wave velocity because the droplet breakup process does not significantly affect the total heat release as long as it is sufficiently fast to sustain the detonation. However, the two-dimensional detonation simulations show that the breakup model and the droplet initial diameter significantly affect the detonation cell size due to the different droplet distributions predicted by various models. The breakup length, which is the distance from the shock wave to the location at which sufficiently small child droplets appear, affects the chemical reaction zone thickness and then the detonation cell size. A longer breakup length will result in a larger detonation cell size.

A high density and low sensitivity carrier explosive promising to replace TNT: 3-Bromo-5-fluoro-2,4,6-trinitroanisole

To address the issues of high saturated vapor pressure, high toxicity, and high viscosity of TNT, this article used a chemical method to synthesize a new carrier explosive BFTNAN. The prepared samples were characterized using scanning electron microscope(SEM), energy spectrum(EDS), x-ray diffraction(XRD), infrared spectrum(IR), x-ray photoelectron spectroscopy(XPS), nuclear magnetic resonance, and elemental analysis techniques. The enthalpy of formation of BFTNAN was measured using a specialized calorimeter that is specially used in testing of explosives and powders. The thermal decomposition performance of BFTNAN was tested by DSC technology. Meanwhile, the mechanical sensitivity, thermal sensitivity, and detonation performance of BFTNAN based melt-cast explosive was also tested. The results of characterizations showed that the prepared sample was indeed BFTNAN. The enthalpy of formation of BFTNAN was determined as ΔHf,BFTNAN = −72.6 kJ·mol−1. At a heating rate of 20 °C·min−1, the thermal decomposition peak of BFTNAN is at TP = 250.6 °C, and the activation energy is EK = 80 kJ·mol−1, which is closed to the Tp and EK values of TNT. This indicates that BFTNAN is a relatively easy to decompose explosive, but the decomposition rate is not fast. The critical temperature for thermal explosion of BFTNAN reached Tb = 216 °C, which is also closed to the Tb value of TNT. The impact and friction sensitivity of BFTNAN were lower than those of TNT, which was closed to those of DNAN. The thermal sensitivity of BFTNAN is lower than TNT. The detonation velocity and heat of explosion of BFTNAN based melt-cast explosive were distinctly higher than those of TNT based explosive. Especially, BFTNAN based melt-cast explosive were of the advantages in chemical energy storage, work capacity, brisance, and ability of acceleration metals.

Theoretical calculation and analysis of the velocity of shaped charge jet with modified collapse velocity model

The application of perforating completion technology in oil and gas field development has gained widespread popularity. Enhancing the efficiency of oil and gas wells relies on increasing the penetration depth, which is influenced by the design of the perforation charge and the strength characteristics of the rock material. However, as a crucial objective function for optimizing perforating charge structures, jet velocity lacks a rapid and accurate calculating method. This article addresses this issue by proposing an improved collapse velocity model using the DP46RDX42-Y perforating charge as a case study. It presents a novel approach for calculating jet velocity based on the unsteady Pugh-Eichelberger-Rostoker (PER) theory. To validate the effectiveness of the proposed method and analyze the impact of different characteristic parameters on jet tip velocity, a series of numerical simulations were conducted using LS-DYNA software combined with Arbitrary Lagrange-Euler (ALE) techniques. Results indicate excellent agreement between the proposed method and the numerical results, demonstrating its superiority over the traditional Gurney formula with an impressive 34.15% increase in accuracy. Notably, this method is particularly suitable for perforating charges with low detonation velocity. Increasing the liner density and decreasing the liner thickness and cone angle is recommended to achieve higher jet tip velocity. Furthermore, the proposed method has the potential for broader application in other perforating charges with varying liner shapes. This study provides a comprehensive and efficient solution for calculating jet velocity, which facilitates optimizing perforating charge structures and calculating penetration depth.

Theoretical study on different substituent-modified derivatives of 6-dinitrophenyl-5,6,7,8-tetrahydro-4-imidazo [4,5-e]furazano[3,4-b] pyrazine.

The compounds of the "565" parent ring structure have received much attention from researchers because of their excellent detonation performance. In the present study, 81 derivatives were designed by introducing different substituents based on 6-dinitrophenyl-5,6,7,8-tetrahydro-4-imidazo[4,5-e]furazano[3,4-b] pyrazine (DIOP), which is a compound of the parent ring structure of 565, and the performance of these derivatives, such as the electronic structure, energy gap, heat of formation, and detonation performance, were investigated. Among these energy-containing derivatives, the density ranges from 1.70 to 2.17g/cm3, the detonation velocity ranges from 8.01 to 10.26km/s, and the detonation pressure ranges from 27.99 to 49.88 GPa. Through comprehensive analysis of several properties of DIOP derivatives, it was found that the oxygen balance of derivatives with the -ONO2 group was greater than zero and close to zero, while the oxygen balance of derivatives with other groups was almost all less than zero. Among them, G8 (D = 10.1km/s, P = 47.72 GPa), H8 (D = 10.11km/s, P = 47.92 GPa), and I8 (D = 10.26km/s, P = 49.88 GPa) had higher detonation velocity and pressure among all derivatives, and their impact sensitivity was better than RDX. Therefore, three potential high-energy and less sensitive energy-containing derivatives, G8, H8, and I8, were screened out. The intramolecular interactions of the three derivatives were further analyzed, and it was found that there were intensive van der Waals interactions and significant spatial steric effects within the molecules, which had a positive effect on reducing the shock sensitivity of the compounds. Moreover, the three derivatives have a large degree of stacking, which leads to a high density. All calculations in this paper are performed using Gaussian16 based on density functional theory. Firstly, the structures of the derivatives were optimized at the level of B3LYP-D3/6-311G**, and then single-site energy calculations were carried out at the level of M06-2X-D3/def2-TZVPP, to reveal the effects of single substituents versus multiple substituents and isomerism on the properties of the DIOP-based energetic derivatives. Multiwfn was used to plot the density of states (DOS) of the derivatives and to calculate the molecular surface electrostatic potential at 0.001 e/Bohr3 electron density, 0.25 Bohr lattice spacing surface.

Single Step Synthesis of gem-Dinitro Methyl-1,2,4-triazole and Its Hydroxylamine Salt: An Alternative to the FOX-7 and Other Benchmark Explosives.

gem-Dinitro methyl based high-energy-density material 5-(dinitromethylene)-4,5-dihydro-1H-1,2,4-triazole (2) and its hydroxylamine salt (4) were synthesized for the first time in a single step and characterized. Further, the structure of 2 was confirmed by single-crystal X-ray diffraction (SCXRD) studies. Interestengly, both the compounds show excellent density (> 1.83 g cm-3), detonation velocity (> 8700 m s-1), pressure (> 30 GPa) and are insensitive toward mechanical stimuli such as impact and friction sensitivity. Considering their synthetic fesibility and balanced energetic performance, compounds 2 and 4 show future prospects as potential next-generation energetic materials for the replacenent of many presently used benchmark high energy density materials such as RDX, FOX-7 and highly insensitive H-FOX.

Design of High-Energy HMX-Based Composite ink and Research on Micro-Detonation Performance

ABSTRACT Using hydroxypropyl methylcellulose (HPMC) aqueous solution and polyethyleneimine (PEI) ethanol solution as the composite bonding system, adding a certain amount of silicone defoamer and toluene diisocyanate (TDI), studied the micro-size charge forming effect of sub-micron Octogen (HMX)-based composite ink under the 3D direct writing printing process and the detonation performance and safety of sub-micron Octogen (HMX) under micro-size charges. The results show that the explosive ink with a solid content (quality score) of 90% has the best rheological properties, excellent printability, and the surface of the molded sample is smooth. The impact energy and friction of the molded sample are 7 J and 324 N, respectively, which are lower than those of the raw material HMX 100% and 237.5%, showing excellent mechanical sensitivity safety performance. In addition, XRD and FTIR show that the HMX crystal form in the composite ink remains β-type, the measured density of the molded sample is 1.432 g·cm−1, the detonation velocity is 6982 m·s−1, and the critical detonation size is 1 × 0.0771 mm, showing excellent microchannel detonation performance.

Amination of nitro-substituted fused triazole: A facile refinement for enhanced comprehensive performance

The fine-tuning of the molecular structures of current explosives to reduce their inherent defects has proven to be an effective synthetic strategy for producing novel energetic compounds with superior overall performance. In this study, this strategy was adopted to modify the heat-labile nitro-substituted fused triazole through facile C-amination and N-amination, resulting in the synthesis of HANTT and ADNTT, respectively, both demonstrating a total yield exceeding 43 %. HANTT, ADNTT, and their derivates were fully characterized by IR, 1H and 13C spectroscopy, differential scanning calorimetry, thermal gravimetric analysis, and elemental analysis. NCI and Hirshfeld surfaces analysis were employed to explore the intermolecular interactions, while LOL-π, NICS, and ICSS analysis were performed to evaluate the aromaticity and stability of these compounds based on their respective single-crystal structures. Most of these insensitive compounds exhibit good thermostability (168–269 °C) and favorable detonation performances (20.2–32.1 GPa and 7679–8862 m s−1). Attributing to its highest heat of formation (545.2 kJ mol−1) among all new energetic compounds, triaminoguanidinium salt 6, with decent thermostability (Td = 203 °C), exhibits an excellent detonation velocity (vD = 8862 m s−1) superior to that of military benchmark explosives RDX (1,3,5-trinitro-1,3,5-triazacyclohexane), thus highlighting its potential as a high-energy insensitive explosive.

Influence and comparison of cylindrical engineered defects on detonation waveshape in a rubberized RDX explosive

AbstractInhomogeneities within explosives affect the sensitivity and detonation waveshape of energetic materials. The influence of voids on explosive initiation has been well documented; however, the effects that voids between 0.1 mm and 10 mm have on a propagating detonation wave remains largely unexplored. The effect of single cylindrical voids on detonation waveshape and re‐initiation was examined here using manufactured voids in a rubberized 1,3,5‐trinitro‐1,3,5‐triazinane (RDX) explosive. Two streak imaging techniques were fielded to investigate void influence. For the first, back‐surface streak imaging, the location of the void on the samples was changed and the resulting change in detonation waveshape at the downstream breakout was captured using a streak camera in cut‐back experiments. The results from this experiment showed the effects of an initial jet form for short cut‐back distances and as shock propagation progressed, the jet formation was absorbed by the unaffected portions of the wave front. The second method, top‐surface streak imaging, was used to investigate the re‐initiation/downstream propagation of the detonation front and the detonation velocity of the rubberized explosive. These experiments were compared to similar experimental results from machined voids in PBX 9501, an 1,3,5,7‐tetranitro‐1,3,5,7‐tetrazocane (HMX)‐based explosive, to investigate the interaction of a detonation wave with a 0.5 mm void for different explosives. The experiments were also compared to simulations using a multi‐dimensional and multi‐material hydrodynamic code. These results showed the influence that small features can have on detonation waveshaping and how explosive properties play a key role in that interaction.

A positional isomer of LLM-116: N—NO2 moiety enhancing the laser ignition combustion performance of nitrogen-rich energetic materials

It has long been a driving force in the development of energetic materials to hunt for novel energetic materials (EMs) with high energy and low sensitivities. Recently, the combination of nitrogen-heterocycles and NNO2 moiety could generate novel energetic derivatives with high energy content and low sensitivity benefiting from the high heat of formation and abundant hydrogen bonding interactions. The critical role of isomerism strategy in tuning the laser ignition combustion performances of EMs is rarely mentioned in the chemical enterprise, although some researches reveal that isomerism strategy has significant effects on their thermal behaviors, mechanical sensitivity and detonation performance. In this work, the positional isomerism of nitramine-pyrazole was investigated, and 3-nitramine-4-nitropyrazole and a series of energetic derivatives were synthesized and well characterized. Their physical properties, energy performance, as well as laser-ignited combustion performance, were further explored. The experimental results showed that all compounds possess excellent detonation pressure, and detonation velocity (P: 26.5∼30.4 GPa, D: 7876∼8377 m·s−1), which were much better than those of trinitrotoluene (TNT) (P: 19.5 GPa and D: 6881 m·s−1). Moreover, all of the resulting energetic derivatives exhibited low mechanical sensitivities (IS>40 J). Interestingly, they also had excellent laser ignited combustion properties owing to the NNO2 moiety attached to nitropyrazole backbone.

Convenient Preparation, Thermal Properties and X-ray Structure Determination of 2,3-Dihydro-5,6,7,8-tetranitro-1,4-benzodioxine (TNBD): A Promising High-Energy-Density Material.

2,3-dihydro-5,6,7,8-tetranitro-1,4-benzodioxine (TNBD), molecular formula = C8H4N4O10, is a completely nitrated aromatic ring 1,4-benzodioxane derivative. The convenient method of TNBD synthesis was developed (yield = 81%). The detailed structure of this compound was investigated by X-ray crystallography. The results of the thermal analysis (TG) obtained with twice re-crystallized material revealed the onset at 240 °C (partial sublimation started) and melting at 286 °C. The investigated material degraded completely at 290-329 °C. The experimental density of 1.85 g/cm3 of TNBD was determined by X-ray crystallography. The spectral properties of TNBD (NMR, FT-IR and Raman) were explored. The detonation properties of TNBD calculated by the EXPLO 5 code were slightly superior in comparison to standard high-energy material-tetryl (detonation velocity of TNBD-7727 m/s; detonation pressure-278 kbar; and tetryl-7570 m/s and 226.4 kbar at 1.614 g/cm3, or 260 kbar at higher density at 1.71 g/cm3. The obtained preliminary results might suggest TNBD can be a potential thermostable high-energy and -density material (HEDM).

Energetic Nitrate-Based Polymer-Bonded Explosives Derived from Sustainable Aza-Michael Reactions.

A novel nontoxic method for processing energetic binder, namely, polyglycidyl nitrate (PGN), using Aza-Michael reactions for deriving high-performance explosive formulations is being reported. The polyol binders used in polymer-bonded explosives (PBX) including PGN are usually cross-linked using isocyanate leading to polyurethane (PU)-based cured solid networks. These reactions require mild reaction conditions and yield good mechanical properties for the PBX but remain challenging due to extraneous reactions of isocyanate resulting in defects in the cured blocks. In addition, the presence of nitrato groups in the vicinity of terminal hydroxyl groups of PGN results in the decuring of cross-linked urethane that affects the storage life of PBX, though PGN-based binder can provide an 18% improvement in the velocity of detonation of PBX at lower solid loadings of 70%. This prevents researchers from exploiting the major performance advantage of using PGN for PBX compositions. This article herein features a green and mild aza-Michael reaction for functional modification of PGN using readily available substrates and triethylene tetramine to form a cross-linked β-aminocarbonyl network. The methodology ensures a void-free, stable, cured network and offers an effective replacement for toxic cure chemistry currently employed for processing of PBX.

Verification and validation of detonation-shock-dynamics relations for explosives described by general equation of state and chemical reaction models

Detonation shock dynamics is a powerful method to model the behaviour of High Explosives (HE). However in order to use this method, the underlying relationship between the local radius of curvature and the detonation speed must be known. Previous work has developed methods to calculate this effect using simple, single-step Arrhenius and polytropic gas, models for the chemical reaction and the equation of state, respectively. In recent years, more complex models for both reaction rates and equations of state have been developed which show better agreement with experimental data than these simple models, especially when considering condensed phase explosives.. This work presents the governing equations for solving these problems in a way that is generalised to use arbitrary equations of state as well as reaction models which may have more than a single step and multiple product species. This implementation is verified against exact solutions, demonstrating that the equations were implemented properly. The verified algorithm is then validated against experimental data and high fidelity simulations, showing that it is able to make accurate predictions in a regime where the underlying assumptions of the governing equations are valid. This approach has many applications: from creating equivalent detonation shock dynamics models for existing reactive burn calibrations for HE; to developing new functional forms and calibrations of reactive burn models for condensed phase high explosives.

Experimental detection of the diamino-pentazolium cation and theoretical exploration of derived high energy materials

In this work, we realized the detection of diamino-pentazolium cation (DAPZ+) in the reaction solution experimentally and proved it to be meta-diamino-pentazole based on the transition state theory. Quantum chemical methods were used to predict its spectral properties, charge distribution, stability and aromaticity. Considering that DAPZ+ has excellent detonation properties, it was further explored by assembling it with N5−, N3− and C(NO2)3− anions, respectively. The results show a strong interaction between DAPZ+ and the three anions, which will have a positive effect on its stability. Thanks to the high enthalpy of formation and density, the calculated detonation properties of the three systems are exciting, especially [DAPZ+][N5−] (D: 10,016 m·s−1; P: 37.94 GPa), whose actual detonation velocity may very likely exceed CL-20 (D: 9773 m·s−1). There is no doubt that this work will become the precursor for the theoretical exploration of new polynitrogen ionic compounds.

The interplay of casing material and detonation wave shock parameters in steel witness plate dent formation

This study uses both experimentation and simulation to investigate how varying casing material around cylindrical Composition-B charges affects witness plate response and diagnoses the cause of the differences in the dents produced. Through experimentation, it was found that consistent dents are produced from repeated tests and characteristically different dents are produced by charges with different casing material. Charges cased in viscoelastic materials produced shallower dents than those without casing. Simulation was validated against the experimental dents, and the detonation wave parameters were measured for 25 differently cased charges: 15 metals and 10 polymers. Regression fit relationships were derived relating dent parameters to casing density, casing impedance, casing tensile strength, detonation pressure, detonation velocity, impulse, and time of arrival. Specifically, it was found that the dent volume was negatively correlated with the detonation velocity and the impulse of the detonation wave was negatively correlated with dent depths across the charge. The density of the casing material was shown to be linked to the width of the witness dents. Additional dent tests were simulated for trinitrotoluene (TNT) charges cased in a single polymer and a single metal. The relationships derived for Composition-B were adjusted to fit TNT using TNT equivalency and calculated the measured detonation wave values to within 10% accuracy. Finally, it was concluded that the measurable distinctions observed in the witness dents were not a result of the casing material itself, but of the changes in the detonation wave caused by its interaction with the casing material.

Nitrous Oxide/Ethanol Cylindrical Rotating Detonation Engine for Sounding Rocket Space Flight

There are few experimental studies on rotating detonation engines (RDEs) with liquid propellants. This study reveals the static thrust performance of a cylindrical RDE with ethanol and liquid nitrous oxide as propellants under atmospheric pressure. This RDE had an inner diameter of 40 mm, a maximum combustor length of 230 mm, a nozzle contraction ratio of 1.7, and a nozzle expansion ratio of 9.1. Nineteen experiments were conducted at total mass flow rates of 184–210 g/s, mixture ratios of 3.6–5.9, and combustion pressures of 0.35–0.46 MPa, resulting in a maximum detonation velocity of 1840 m/s (approximately 80% of the theoretical detonation velocity, 2251 m/s), maximum thrust at sea level of 294 N, and maximum specific impulse at sea level of 148 s. In addition, the maximum characteristic exhaust velocity, c*, was 1716 m/s, which was 99% of the theoretical value. The characteristic length of the combustion chamber at this time was 0.15 m. Since conventional rocket combustion requires 1.57 m to achieve the same c* efficiency, this study shows that detonation combustion can reduce the combustor size by 88%.

Experimental and numerical study on the mechanism of interlayer explosive welding

Currently, a gap in understanding the mechanism of interlayer explosives exists. This study systematically investigated this mechanism using TP 270C/SUS 821L1 to fill this knowledge gap. By comparing the outcomes of direct and interlayer welding through methods such as optical microscope (OM), computed tomography (CT), electron probe micro-analysis (EPMA), electron backscatter diffraction (EBSD), transmission electron microscopy (TEM), nanoindentation, and tensile shear test, it was found that an interlayer can significantly lessen the energy at the target interface. This was further evident when comparing welds with varying interlayer thicknesses, showing that thinner interlayers lead to less energy transfer between the flying plate and the interlayers. Notably, at an interlayer thickness of 0.1 mm, the welding interface appeared irregular. The smoothed particle hydrodynamics (SPH) method was employed to simulate the welding, highlighting the interlayer's impact on factors like pressure, jet, temperature, and melting. This simulation also explained why the 0.1 mm interlayer had an irregular interface due to jetting affecting the welding between the flyer plate and interlayer. The study also analyzed the weldability window in interlayer explosive welding, noting how the interlayer influenced its upper and lower limits. The relation between interlayer thickness and the constant k in the lower limit was examined, along with the minimum velocity needed for the flyer plate to generate a jet VP. Their relationship satisfied exponential functions in the detonation velocity range of 1800–3000 m/s. This study thus established a link between traditional and interlayer explosive welding.

Trinitromethyl-Substituted 1H-1,2,4-Triazole Bridging Nitropyrazole: A Strategy of Utterly Manipulable Nitration Achieving High-Energy Density Material.

Nitro groups have been demonstrated to play a decisive role in the development of the most powerful known energetic materials. Two trinitromethyl-substituted 1H-1,2,4-triazole bridging nitropyrazoles were first synthesized by straightforward routes and were characterized by chemical (MS, NMR, IR spectroscopy, and single-crystal X-ray diffraction) and experimental analysis (sensitivity toward friction, impact, and differential scanning calorimetry-thermogravimetric analysis test). Their detonation properties (detonation pressure, detonation velocity, etc.) were predicted by the EXPLO5 package based on the crystal density and calculated heat of formation with Gaussian 09. These new trinitromethyl triazoles were found to show suitable sensitivities, high density, and highly positive heat of formation. The combination of exceedingly high performances superior to those of HMX (1,3,5,7-tetranitrotetraazacyclooctane), and its straightforward preparation highlights compound 8 as a promising high-energy density material (HEDM). This work supports the effectivity of utterly manipulable nitration and provides a generalizable design synthesis strategy for developing new HEDMs.

Effect of AP distribution on energy release characteristics and functional force of HMX/AP/Al explosives

AbstractIn order to understand the reaction kinetics of HMX/AP/Al ternary system, the different distribution of AP in HMX/AP/Al explosives was realized by two different preparation techniques. Detonation test results show that the detonation velocity, explosion heat and detonation pressure of HAP samples are higher than those of HAl samples, but the extent of improvement is not high, not more than 5 %. The results of scanning electron microscopy showed that AP in HAP samples was distributed on the surface of HMX crystal. AP were dispersed around HMX crystals in HAl samples. The experimental results of explosive fireball performance show that the fireball expansion speed of HAP samples is better than that of HAl samples, demonstrating a good fireball effect. Underwater test results show that the shock wave peak pressure and bubble pulsation period of HAP samples increase by 3.06 % and 7.95 % respectively, and shock wave energy and bubble energy increase by 9.8 % and 25.42 % compared with bubble energy. The experimental results show that HAP samples are superior to HAl samples in accelerating ability of Al flies. The dispersion of AP on the HMX crystal surface promotes the energy release of HMX/AP/Al explosives more.

Observation of Oblique Laser-Supported Detonation Wave Propagating in Atmospheric Air

Elucidation of the propagation velocity of a laser-supported detonation (LSD) wave and its propagation mechanism is necessary for various engineering applications. This study was conducted to observe an oblique laser-supported detonation wave off the laser axis. The relation between the local laser intensity and detonation-wave propagation velocity was investigated. For this purpose, the time-space distribution of the laser intensity was measured precisely. The change of the LSD wavefront shape was visualized using an ultrahigh-speed camera. The relation between the local laser intensity and the propagation velocity of the oblique LSD wave measured off the laser axis was found to be identical to the relation between the local laser intensity and the detonation propagation velocity at the laser axis.