Shock Waves最新文献

{"title":"Shock structures and post-impact jetting in hypervelocity droplet impingement","authors":"M. Viqueira-Moreira,&nbsp;A. R. Dworzanczyk,&nbsp;J. D. Langhorn,&nbsp;M. A. Libeau,&nbsp;J. B. Middlebrooks,&nbsp;N. J. Parziale,&nbsp;C. Brehm","doi":"10.1007/s00193-026-01292-2","DOIUrl":"10.1007/s00193-026-01292-2","url":null,"abstract":"<div><p>The shock dynamics resulting from high-speed droplet impingement on a rigid surface are investigated employing high-resolution schlieren imaging and numerical simulations based on the five-equation model. A key finding is that, in contrast to the common emphasis on jetting-induced dynamics, the long-time shock morphology is governed not by explosive shocks generated during jetting, but rather by the reflection of the droplet’s own shock wave off the solid wall. The resulting shock structure is found to be robust across a wide range of densities and breakup states, and its evolution is shown to depend primarily on the impact Mach number. Axisymmetric and 3D simulations both capture the wall-reflected envelope with high fidelity, despite shared limitations in modeling post-impact jetting dynamics. The presented results clarify the physical mechanisms shaping post-impingement shock evolution and highlight the modeling trade-offs involved in capturing jet-driven transients. This paper provides a unique experimental and numerical dataset that can be used as a reference for future studies.</p></div>","PeriodicalId":775,"journal":{"name":"Shock Waves","volume":"36 3","pages":""},"PeriodicalIF":1.8,"publicationDate":"2026-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00193-026-01292-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149189522","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Jets from point-initiated hemispherical-lined shaped charges","authors":"D. C. Marable,&nbsp;J. C. Sweitzer,&nbsp;N. J. Ginga","doi":"10.1007/s00193-026-01287-z","DOIUrl":"10.1007/s00193-026-01287-z","url":null,"abstract":"<div><p>The capacity of analytical models to accurately represent real-world phenomena is critical to the study of jet formation physics. Shaped charge performance can be influenced by the detonation wave geometry as it interacts with the liner, making accurate representation of the wavefront essential when evaluating hemispherical liners. Previous work established an analytic foundation for predicting jet characteristics of plane-wave-initiated, hemispherical-lined charges. Extending this framework, the present study introduces a modified set of analytic equations describing the collapse and jet formation of constant-wall-thickness, hemispherical-lined shaped charges initiated on or off the axis of symmetry. The proposed model is first evaluated against experimental data from two on-axis-initiated charges. Agreement between experiments and continuum-based simulations establishes a basis for further assessment, after which model predictions are also compared with simulations of identical configurations. The model is then examined across a matrix of simulations spanning variations in charge geometry and both on- and off-axis initiation locations. Although further research is warranted to identify more appropriate methods for describing collapse velocity profiles, the analytic framework predicts jet characteristics with sufficient accuracy relative to simulations that neglect liner material strength when a well-characterized profile is used as input. For the copper-lined, LX-14 simulation cases neglecting liner material strength and having an explosive-to-liner mass-per-unit-area ratio less than 17.20, the model yields an average coefficient of determination of 0.91 and an average mean absolute error of <span>(pm ~0.23)</span> km/s. These matrix results, together with the close agreement obtained for simulations of the two experimental configurations neglecting liner material strength, support the validity of the proposed point-initiation model across the configurations evaluated in this study. Comparisons with the experimental data and additional simulations incorporating liner material strength, however, indicate that further refinement is needed to more fully account for material strength effects beyond those represented by the simple empirical jet-tip-truncation approach. Despite this, the present framework provides an efficient and practical method for predicting jet characteristics of point-initiated, hemispherical-lined shaped charges.</p></div>","PeriodicalId":775,"journal":{"name":"Shock Waves","volume":"36 3","pages":""},"PeriodicalIF":1.8,"publicationDate":"2026-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149132654","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical evaluation of afterburning parameters in partially confined TNT explosions informed by experiments","authors":"I. E. Edri","doi":"10.1007/s00193-026-01280-6","DOIUrl":"10.1007/s00193-026-01280-6","url":null,"abstract":"<div><p>Afterburning, which is the secondary combustion of detonation products with ambient oxygen, can substantially increase the energy released in confined TNT explosions. Predicting this phenomenon in partially confined environments is considerably more challenging than under ideal, fully confined conditions, yet it is essential for accurate estimation of internal blast loads. This study evaluates afterburning behavior in partially confined scenarios by correlating numerical simulations with experimental data. Numerical modeling is based on previously conducted experiments, serving as a database to assess the afterburning contribution in Viper::Blast CFD simulations. An engineering model is utilized to account for the combustion of fuel-rich detonation products, where the total energy release and characteristic duration are controlled by two key parameters. A theoretical framework is first introduced to estimate the maximum potential afterburning energy under full confinement for both oxygen-rich and oxygen-deficient conditions. Two scenarios are subsequently analyzed: fully confined and partially confined explosions. For the former, simulations show good agreement with published experimental data when the maximum theoretical energy is applied. For the latter, a comprehensive numerical study identifies the effective magnitude and timing of afterburning that best fits the tests, highlighting the significant influence of venting on energy release. Finally, an additional literature-based case study is simulated to further illustrate the effect of venting. The analysis emphasizes the caution required when extrapolating these parameters to different confinement or venting conditions and underscores the need for further experimental and numerical investigation.</p></div>","PeriodicalId":775,"journal":{"name":"Shock Waves","volume":"36 3","pages":""},"PeriodicalIF":1.8,"publicationDate":"2026-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00193-026-01280-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149132656","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Field monitoring and numerical analysis of blast-induced air shock wave propagation in Y-shaped metal mine tunnels","authors":"Y. Long,&nbsp;Y. Ye,&nbsp;Y. Huang,&nbsp;B. Li,&nbsp;J. Jiang,&nbsp;T. Lei,&nbsp;W. Zhao","doi":"10.1007/s00193-026-01276-2","DOIUrl":"10.1007/s00193-026-01276-2","url":null,"abstract":"<div><p>Given the inadequate understanding of blast-induced air shock wave propagation mechanisms in geometrically complex underground tunnels within metal mines, this study conducted field monitoring using iSD-404 testers and IEPE sensors, combined with ANSYS/LS-DYNA simulation technology, to systematically study the dynamic characteristics of air shock waves in Y-shaped tunnels and quantify the overpressure characteristics and attenuation rate of air shock waves, revealing that Y-shaped configurations achieve superior energy dissipation compared to straight or turning tunnels. Moreover, closed bifurcations were found to amplify pressure peaks to hazardous levels via wave reflection, while open boundaries promoted effective pressure venting. Parametric analysis further demonstrated that bifurcation angles of 75<span>(^{circ })</span> optimize shock wave energy dispersion, whereas bifurcation lengths exceeding 60 m have negligible impact on peak overpressure attenuation. These findings provide a scientific basis for the optimization of tunnel geometry and protective system design in underground mining operations.</p></div>","PeriodicalId":775,"journal":{"name":"Shock Waves","volume":"36 3","pages":""},"PeriodicalIF":1.8,"publicationDate":"2026-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149132341","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pressure–time history scaling for hypervelocity water entry","authors":"J. Smith,&nbsp;M. Viqueira-Moreira,&nbsp;M. Sendrey,&nbsp;P. Thasu,&nbsp;C. Brehm,&nbsp;B. Schmidt","doi":"10.1007/s00193-026-01285-1","DOIUrl":"10.1007/s00193-026-01285-1","url":null,"abstract":"<div><p>Numerical simulations are performed for hypervelocity water entry of spherical projectiles, validated against experimental data. The scaling of principal phenomena is investigated using time histories of the pressure at the stagnation point, the axial portion of the shock wave, and the radial portion of the shock wave. The scaling analysis of the pressure is performed via a parameter sweep of projectile impact velocity, density, diameter, and impact kinetic energy. The pressure in all these regions scales most strongly with impact velocity. For the stagnation point and the axial shock wave, the pressure also scales strongly with the projectile density and to a lesser extent with diameter and kinetic energy. The radial shock wave pressure scales only with the projectile diameter at a given impact velocity. Lastly, these pressure histories are non-dimensionalized using a combination of dimensional parameters, i.e., the reference dynamic pressure, a kinetic energy-based characteristic length scale, the impact Mach number, and the water sound speed. Empirical fits are obtained that can be used as predictive tools, with the curves from the computations collapsing well for all locations investigated.\u0000</p></div>","PeriodicalId":775,"journal":{"name":"Shock Waves","volume":"36 3","pages":""},"PeriodicalIF":1.8,"publicationDate":"2026-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00193-026-01285-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149133086","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of freestream noise and boundary-layer transition on hypersonic shock-wave/boundary-layer interaction unsteadiness","authors":"E. Nicotra,&nbsp;S. Bane,&nbsp;J. Jewell","doi":"10.1007/s00193-026-01286-0","DOIUrl":"10.1007/s00193-026-01286-0","url":null,"abstract":"<div><p>The low-frequency shock and separation unsteadiness resulting from a three-dimensional transitional shock-wave/boundary-layer interaction is investigated for different freestream noise levels and incoming boundary-layer states in a quiet Mach-6 wind tunnel. In low-disturbance flow, the cone-slice-ramp geometry is studied with and without upstream boundary-layer trips, resulting in upstream-transitional and interaction-transitional SWBLI, respectively. When applied, the trips excite the second-mode instability, and the unsteady separation motion is studied for a range of second-mode magnitudes in the transitional upstream boundary layer. The effect of freestream noise is studied by operating the wind tunnel in both its low-disturbance and conventional-noise configurations. Unsteady separation motion is tracked by identifying the shear-layer location in schlieren visualization videos; pressure fluctuations are measured in the incoming boundary layer and inside the separation bubble. Exciting the second-mode instability in the boundary layer in quiet flow initially increases the magnitude of the unsteadiness and alters its frequency content by amplifying oscillations at <span>(textrm{Sr}_L=)</span>  0.025–0.05; however, as second-mode amplitude increases and separation length decreases, this trend reverses and the unsteadiness is suppressed. The comparison of upstream-transitional SWBLI in quiet and noisy flows suggests that the pressure fluctuations in the noisy freestream are interacting with the mechanism responsible for SWBLI and significantly amplifying the unsteadiness over all frequencies.</p></div>","PeriodicalId":775,"journal":{"name":"Shock Waves","volume":"36 3","pages":""},"PeriodicalIF":1.8,"publicationDate":"2026-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00193-026-01286-0.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149132931","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Classification of detonation length scales and post-shock states through spatio-temporal velocity fields","authors":"D. R. Hart,&nbsp;L. Berson,&nbsp;A. J. Morales,&nbsp;R. Hytovick,&nbsp;R. Cideme,&nbsp;K. A. Ahmed","doi":"10.1007/s00193-026-01288-y","DOIUrl":"10.1007/s00193-026-01288-y","url":null,"abstract":"<div><p>The ability to predict and control detonation waves is of significant interest to several fields, including high-speed propulsion, industrial safety, and astrophysics. Understanding multidimensional detonation behavior requires identifying a characteristic length scale of a detonation, one of which is the cell width (or cell length). This study aims to validate the use of spatio-temporal velocity fields of the leading shock (i.e., velocity maps) as a method of measuring cell structure data through a series of experiments of stoichiometric methane–oxygen mixtures with varying levels of nitrogen dilution in a thin channel. Velocity maps were extracted from megahertz shadowgraphy, and the cell sizes measured from the velocity maps, soot foils, and shadowgraphy images were compared and showed good agreement. The agreement between diagnostics validated velocity maps as a method of measuring cellular length scales. The velocity maps were then used to compute the post-shock state of the detonation, and high-resolution spatio-temporal pressure and temperature fields of the von Neumann state were created for the first time. These von Neumann maps contain the same cell structure data that velocity maps do and also provide the local post-shock dynamics of a non-uniform shock.</p></div>","PeriodicalId":775,"journal":{"name":"Shock Waves","volume":"36 3","pages":""},"PeriodicalIF":1.8,"publicationDate":"2026-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00193-026-01288-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149133085","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental measurement of intracranial strains under breacher-level blast exposure","authors":"E. Webster,&nbsp;R. Banton,&nbsp;G. St-Onge,&nbsp;B. Genest,&nbsp;S. Ouellet,&nbsp;A. R. Harris,&nbsp;O. E. Petel","doi":"10.1007/s00193-026-01272-6","DOIUrl":"10.1007/s00193-026-01272-6","url":null,"abstract":"<div><p>Blast-induced traumatic brain injury (bTBI) is an ongoing concern for military and law enforcement personnel exposed to repeated low-level blasts. While strain-driven axonal damage has been proposed as a mechanism of primary blast injury, the role of strain under occupationally relevant conditions remains poorly defined. To investigate the role of strain in blast-induced injury, we measured strain in a Sylgard 527-filled surrogate headform exposed to shock-tube blasts of ~75-kPa incident overpressure and ~5-ms positive-phase duration, which is representative of breacher-level blast exposures. High-speed imaging and digital image correlation revealed that intracranial strains are consistently below 0.5%. These values are much lower than the reported thresholds for both long-term potentiation (3.7–6.7% strain) and moderate-to-severe axonal injury (5–10% strain). Our findings are consistent with prior finite element simulations of comparable blast exposures (50–100  kPa, 4–8  ms) which similarly found less than 1% strains for 50–100  kPa incident overpressures. In this head surrogate, the results indicate that strain is unlikely to be a dominant mechanism of injury at breacher-level exposures and instead emphasize the importance of experimental testing for other potential injury mechanisms, such as cavitation.</p></div>","PeriodicalId":775,"journal":{"name":"Shock Waves","volume":"36 3","pages":""},"PeriodicalIF":1.8,"publicationDate":"2026-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148986584","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fast-flame-to-detonation transition in a round tube: comparison with a square channel","authors":"M. Moran,&nbsp;G. Ciccarelli","doi":"10.1007/s00193-026-01279-z","DOIUrl":"10.1007/s00193-026-01279-z","url":null,"abstract":"<div><p>The deflagration-to-detonation transition (DDT) downstream of a 76%-blockage-ratio perforated plate was investigated in a 7.6-cm-inner-diameter polycarbonate round tube. Tests were primarily conducted in stoichiometric propane–oxygen mixtures with and without argon dilution at initial pressures of 4.2–35 kPa, and the results were compared to experiments conducted in a square channel of identical transverse dimension and with a nearly identical perforated plate. Simultaneous high-speed side- and end-view photography identified the precise location of detonation onset, and soot-coated foils provided a record of the shock dynamics preceding the onset of detonation, and the subsequent detonation cell structure. Prompt detonation initiation was independent of channel geometry, occurring at identical conditions as in the square channel. At lower initial pressures, detonation was initiated either at the channel centerline following a near-symmetric shock implosion, or subsequently following shock reflection of the near-symmetric expanding shock at the tube wall. For the “stable” argon-diluted mixtures, more reactive conditions were required for DDT in the round tube than in the square channel, demonstrating that for regular-cell structure mixtures detonation initiation is promoted by shock focusing in the channel corners. For the “unstable” <span>({textrm{C}}_{3}{textrm{H}}_{8}+5{textrm{O}}_{2})</span> mixture, there was little difference in the DDT limit for the round and square channels, indicating that detonation initiation driven by hot-spot formation following transverse wave collisions is dominant, i.e., as effective as shock focusing in the corner.</p></div>","PeriodicalId":775,"journal":{"name":"Shock Waves","volume":"36 3","pages":""},"PeriodicalIF":1.8,"publicationDate":"2026-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148926847","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Detonation propagation in weakly confined gases","authors":"Y. K. Wahba,&nbsp;X. C. Mi,&nbsp;C. B. Kiyanda,&nbsp;A. J. Higgins","doi":"10.1007/s00193-026-01274-4","DOIUrl":"10.1007/s00193-026-01274-4","url":null,"abstract":"<div><p>This study investigates the propagation of detonations along a layered configuration where a reactive gas is weakly confined by a hotter inert layer. Computational Fluid Dynamics (CFD) simulations are performed using a single-step, non-Arrhenius reaction model designed to intentionally suppress cellular instabilities, thereby enabling the formulation of a theoretical framework that can be directly compared with the simulation results. The simulations reach a quasi-steady state, revealing distinct flowfield regimes that depend on the acoustic impedance ratio and relative layer thicknesses, with some detonations exhibiting velocity deficits while others propagate above the ideal Chapman–Jouguet (CJ) speed. Analytical models are developed to interpret these regimes. When a precursor shock is observed in the inert layer, the detonation is overdriven; this phenomenon is modeled using shock-polar analysis and velocity estimates based on the approach of Mitrofanov (Acta Astronaut 3:995–1004, 1976). An analytical criterion for the onset of the precursor shock is proposed. In underdriven scenarios, the detonation front exhibits positive curvature, which is analyzed using a geometric construction approach, wherein the relationship between wave speed and front curvature is evaluated a priori. In underdriven cases, a simplified characteristic-based model is introduced to capture the decay of the shock wave in the inert layer, after which a shock-polar analysis is applied to determine the resulting wave interaction. The predictions from these analytical models are assembled into a phase map that delineates regions of overdriven and underdriven behavior, along with the corresponding shock interactions, in the space of acoustic impedance and area ratios. This map is then compared directly with the CFD results. The combined numerical–theoretical framework presented in this paper clarifies transition mechanisms that govern layered detonations and provides insights into detonation dynamics relevant to rotating detonation engines in which the detonation is bounded by the hotter combustion products formed from a previous cycle.</p></div>","PeriodicalId":775,"journal":{"name":"Shock Waves","volume":"36 3","pages":""},"PeriodicalIF":1.8,"publicationDate":"2026-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148782104","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}