Shock Waves最新文献

{"title":"Semi-confined blast loading: experiments and simulations of internal detonations","authors":"M. Kristoffersen,&nbsp;F. Casadei,&nbsp;G. Valsamos,&nbsp;M. Larcher,&nbsp;K. O. Hauge,&nbsp;A. Minoretti,&nbsp;T. Børvik","doi":"10.1007/s00193-024-01161-w","DOIUrl":"10.1007/s00193-024-01161-w","url":null,"abstract":"<div><p>Far-field blast loading has been studied extensively for decades. Close-in, confined, and semi-confined detonations less so, partly because it is difficult to obtain good experimental data. The increase in computational power in recent years has made it possible to conduct studies of this kind numerically, but the results of such simulations ultimately depend on experimental validation and verification. This work thus aims at using reliable experiments to validate and verify numerical models developed to represent blast loading in general. Test rigs consisting of massive steel cylinders with pressure sensors were used to measure the pressure profiles of semi-confined detonations with different charge sizes. The experimental data set was then used to assess numerical models appropriate for simulating blast loading. In general, the numerical results were in excellent agreement with the experimental data, in both qualitative and quantitative terms. These results may in turn be used to analyse structures exposed to internal blast loads, which constitutes the next phase of this research project.</p></div>","PeriodicalId":775,"journal":{"name":"Shock Waves","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00193-024-01161-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140575498","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":"Breakdown regime of a shielded vortex interacting with a standing normal shock: a numerical study","authors":"A. Kundu","doi":"10.1007/s00193-024-01163-8","DOIUrl":"10.1007/s00193-024-01163-8","url":null,"abstract":"<div><p>Numerical simulation results of a convecting shielded vortex interacting with a normal shock using a compact scheme in the convecting upwind and split pressure framework are presented. We explore the parameter space spanned by vortex Mach number and incident Mach number to look for combinations of the parameters which lead to vortex breakdown. The incident and vortex Mach numbers covered are on the higher side, where relatively less information is available. It is well known that for a weak shock, the vortex retains its original shape and for stronger shocks it breaks down. In-between these two extremes, there is a region where the vortex neither retains its original shape nor does it break into small pieces. We determine the vortex breakdown and transition regions that have not so far been reported in shock–vortex interaction studies. A number of cases have been studied, and a vortex breakdown criterion for the cases considered is proposed.</p></div>","PeriodicalId":775,"journal":{"name":"Shock Waves","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140575695","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":"A simple, self-sufficient approach for the design of shock tube driver insert","authors":"Y. Tan, Z. Li, R. Mével","doi":"10.1007/s00193-024-01157-6","DOIUrl":"https://doi.org/10.1007/s00193-024-01157-6","url":null,"abstract":"<p>Experimental data obtained in shock tubes, including ignition delay-time and species concentration profiles, are among the most significant parameters in combustion studies. Although shock tubes are widely considered as a quasi-ideal reactor for high-temperature studies, it involves a number of non-ideal effects such as a time-dependent pressure increase within the test section. This non-ideal pressure rise induces inaccuracy in the shock tube measurements. To overcome this issue, the driver insert strategy has proven to be successful. Nevertheless, the approaches presented in the literature to design such a driver insert either are not self-sufficient, i.e., they rely on external software, or lack flexibility. In this study, a simple, self-sufficient, fully analytical approach implemented in a MATLAB code has been developed to design a driver insert for the control of the rate of pressure rise in the test volume. The tip and end positions of the insert, as well as the effect of area change ratio on pressure behind reflected shock are obtained by the code. Extensive validation is performed against previous results from the literature and new data generated with several numerical codes.</p>","PeriodicalId":775,"journal":{"name":"Shock Waves","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140575502","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":"Bilayer surrogate brain response under various blast loading conditions","authors":"C. Norris,&nbsp;B. Arnold,&nbsp;J. Wilkes,&nbsp;C. Squibb,&nbsp;A. J. Nelson,&nbsp;H. Schwenker,&nbsp;J. Mesisca,&nbsp;A. Vossenberg,&nbsp;P. J. VandeVord","doi":"10.1007/s00193-024-01158-5","DOIUrl":"10.1007/s00193-024-01158-5","url":null,"abstract":"<div><p>Variations in the experimental constraints applied within blast simulations can result in dramatically different measured biomechanical responses. Ultimately, this limits the comparison of data between research groups and leads to further inquisitions about the “correct” biomechanics experienced in blast environments. A novel bilayer surrogate brain was exposed to blast waves generated from advanced blast simulators (ABSs) where detonation source, boundary conditions, and ABS geometry were varied. The surrogate was comprised of Sylgard 527 (1:1) as a gray matter simulant and Sylgard 527 (1:1.2) as a white matter simulant. The intracranial pressure response of this surrogate brain was measured in the frontal region under primary blast loading while suspended in a polyurethane spherical shell with 5 mm thickness and filled with water to represent the cerebrospinal fluid. Outcomes of this work discuss considerations for future experimental designs and aim to address sources of variability confounding interpretation of biomechanical responses.</p></div>","PeriodicalId":775,"journal":{"name":"Shock Waves","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00193-024-01158-5.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140575496","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":"Assessment of the sensitivity to detonation of the gaseous pyrolytic products formed during the thermal decomposition of ammonium dinitramide and its related ionic liquids","authors":"N. Itouyama, X. Huang, R. Mével, K. Matsuoka, J. Kasahara, H. Habu","doi":"10.1007/s00193-024-01160-x","DOIUrl":"https://doi.org/10.1007/s00193-024-01160-x","url":null,"abstract":"<p>Ammonium dinitramide (ADN, <span>([textrm{NH}_{4}]^{+}[textrm{N}(textrm{NO}_{2})_{2}]^{-})</span>) and its related propellants are promising high energy density materials for new-generation space propulsion. In order to ensure their safe utilization, it is of primary importance to assess the risk of accidental combustion events such as detonation. Thus, focusing on ADN and its related propellant composed of ADN, monomethylamine nitrate, and urea with weight percentages of 40:40:20 (AMU442), we have studied the properties and steady structure of detonation propagating in gaseous mixtures formed by their thermal decomposition. The AMU442-based mixture exhibits higher von Neumann and Chapman–Jouguet temperatures and pressures than the ADN-based mixture. The study of their steady detonation structure reveals that the gaseous species resulting from the decomposition of AMU442 have higher detonability than the ones resulting from the decomposition of ADN alone. This is in contrast to a previous study about the safety of these propellants in their original (solid or liquid) phase, i.e., AMU442 has lower sensitivity/reactivity to incident impact than ADN. Thermochemical analyses performed for both mixtures show that the decomposition of <span>(textrm{HNO}_{3})</span> plays a dominant role for the energy consumption and initiation of the reaction by releasing both OH and <span>(textrm{NO}_{2})</span>. For the ADN-based mixture, the reactions involving <span>(textrm{HN}(textrm{NO}_{2})_{2})</span> and <span>(textrm{HNO}_{3})</span> are the most sensitive, whereas for the AMU442-based mixture, the most sensitive reactions involve <span>(textrm{CH}_{3}textrm{NH}_{2})</span>, <span>(textrm{CH}_{2}textrm{NH}_{2})</span>, and <span>(textrm{HNO}_{3})</span>. Reaction pathway diagrams emphasize the higher complexity of the chemical pathways for the AMU442-based mixture because of the presence of <span>([textrm{CH}_{3}textrm{NH}_{3}]^{+}[textrm{NO}_{3}]^{-})</span> and <span>(textrm{CH}_{4}textrm{N}_{2}textrm{O})</span> in the initial mixture. An uncertainty quantification study demonstrated that the calculated induction lengths exhibit an uncertainty on the order of 50%.</p>","PeriodicalId":775,"journal":{"name":"Shock Waves","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140575692","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":"Experimental study on the use of the ARM Cortex M7 processor for measuring far-field blast waves","authors":"M. du Plessis,&nbsp;N. Mahomed,&nbsp;R. Heise","doi":"10.1007/s00193-023-01154-1","DOIUrl":"10.1007/s00193-023-01154-1","url":null,"abstract":"<div><p>The ongoing study of blast waves and blast wave mitigation continues to play an essential role in protecting structures and personnel. The methodology, however, for capturing far-field blast waves in large-scale tests has remained largely unchanged for three decades, relying on large arrays of pressure transducers connected by hundreds of meters of cabling and requiring a considerable amount of time to set up. This paper evaluates the use of a modern low-cost microprocessor with high computational power to capture blast waves with sufficient fidelity to provide scientists and engineers with credible data. The system utilizes an ARM Cortex M7 processor as an experimental data acquisition (DAQ) system for measuring far-field blast waves in an open-air blast arena at sampling speeds of up to 1.8 Msps (megasamples per second). The experimental system’s performance was evaluated by comparing it to a traditional commercial system used for measuring blast waves. The comparison showed an average Spearman correlation coefficient <i>r</i> of 0.928 between the two systems, suggesting a low variance between the commercial and experimental DAQ systems. This suggests that, despite its simplicity, the experimental system is an effective and low-cost alternative for accurately measuring blast waves.\u0000</p></div>","PeriodicalId":775,"journal":{"name":"Shock Waves","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00193-023-01154-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140316261","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 and numerical investigation of shock wave-based methane pyrolysis for clean H $$_2$$ production","authors":"A. M. Ferris, P. Biswas, R. Choudhary, R. K. Hanson","doi":"10.1007/s00193-024-01159-4","DOIUrl":"https://doi.org/10.1007/s00193-024-01159-4","url":null,"abstract":"<p>Shock wave reforming, or the use of shock waves to achieve the necessary high-temperature conditions for thermal cracking, has recently gained commercial interest as a new approach to clean hydrogen (H<span>(_2)</span>) generation. Presented here is an analysis of the chemical kinetic and gasdynamic processes driving the shock wave reforming process, as applied to methane (CH<span>(_4)</span>) reforming. Reflected shock experiments were conducted for high-fuel-loading conditions of 11.5–35.5% CH<span>(_4)</span> in Ar for 1790–2410 K and 1.6–4 atm. These experiments were used to assess the performance of five chemical kinetic models. Chemical kinetic simulations were then carried out to investigate the thermal pyrolysis of 100% CH<span>(_4)</span> across a wide range of temperature and pressure conditions (1400–2600 K, 1–30 atm). The impact of temperature, pressure, and reactor assumptions on H<span>(_2)</span> conversion yields was explored, and conditions yielding optimal H<span>(_2)</span> production were identified. Next, the gasdynamic processes needed to achieve the target temperature and pressure conditions for optimal H<span>(_2)</span> production were investigated, including analysis of requisite shock strengths and potential driver gases. The chemical kinetic and gasdynamic analyses presented here reveal a number of challenges associated with the shock wave reforming approach, but simultaneously reveal opportunities for further research and innovation.</p>","PeriodicalId":775,"journal":{"name":"Shock Waves","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140025858","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":"Study of unsteadiness due to 3-D shock–boundary layer interaction in flow over a square-faced protuberance","authors":"K. Ramachandra,&nbsp;S. Bhardwaj,&nbsp;J. N. Murugan,&nbsp;R. Sriram","doi":"10.1007/s00193-023-01156-z","DOIUrl":"10.1007/s00193-023-01156-z","url":null,"abstract":"<div><p>The dynamics of shock-induced unsteady separated flow past a three-dimensional square-faced protuberance are investigated through wind tunnel experiments. Time-resolved schlieren imaging and unsteady surface pressure measurements are the diagnostics employed. Dynamic mode decomposition (DMD) of schlieren snapshots and analysis of spectrum and correlations in pressure data are used to characterize and resolve the flow physics. The mean shock foot in the centreline is found to exhibit a Strouhal number of around 0.01, which is also the order of magnitude of the Strouhal numbers reported in the literature for two-dimensional shock–boundary layer interactions. The wall pressure spectra, in general, shift towards lower frequencies as one moves away (spanwise) from the centreline with some variation in the nature of peaks. The cross-correlation analysis depicts the strong dependence of the mean shock oscillations and the plateau pressure region, and disturbances are found to travel upstream from inside the separation bubble. Good coherence is observed between the spanwise mean shock foot locations till a Strouhal number of about 0.015 indicating that the three-dimensional shock foot largely moves to-and-fro in a coherent fashion.</p></div>","PeriodicalId":775,"journal":{"name":"Shock Waves","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140004410","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":"Swept shock/boundary-layer interaction control using micro-vortex generators","authors":"A. Khan,&nbsp;M. Chidambaranathan,&nbsp;S. B. Verma,&nbsp;R. Kumar","doi":"10.1007/s00193-023-01155-0","DOIUrl":"10.1007/s00193-023-01155-0","url":null,"abstract":"<div><p>Passive flow control devices, such as vortex generators (VGs), have shown to be successful in controlling flows associated with shock-wave/boundary-layer interactions. In the present work, we investigate the effectiveness of micro-VGs in controlling the interactions of the boundary layer with a swept shock wave generated by a semi-infinite fin placed in a Mach 2 freestream generated in a wind tunnel with a rectangular cross section. The strength of the interaction is varied by changing the angle of attack of the fin in the range <span>(alpha = 3^circ )</span>–<span>(15^circ )</span>. Arrays of micro-VGs are placed upstream of the interaction zone in two different configurations: (I) along a line perpendicular to the freestream and (II) along a line inclined to the freestream following the conical topology of the interaction zone. A parametric analysis is done for the rectangular, ramp, and Anderson-type micro-VGs for three different heights. Unsteady and time-averaged pressure measurements are done using arrays of ports spanned radially across the interaction zone. Surface flow patterns are obtained using the oil-flow visualisation technique. It is observed that VGs offer significantly better control effectiveness when placed inclined to the freestream along the interaction region. The rectangular VGs demonstrate a maximum shift (as much as <span>(8^circ )</span>) in the upstream influence line azimuthally towards the fin resulting in a decrease in the size of the separation region. Footprints obtained from the oil-flow experiments give important signatures of the vortices that are shed from the VGs and are responsible for the flowfield distortion in the interaction zone.\u0000</p></div>","PeriodicalId":775,"journal":{"name":"Shock Waves","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140004407","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":"Extension of the normal shock wave relations for calorically imperfect gases","authors":"C. H. B. Civrais,&nbsp;C. White,&nbsp;R. Steijl","doi":"10.1007/s00193-023-01153-2","DOIUrl":"10.1007/s00193-023-01153-2","url":null,"abstract":"<div><p>An extension to the normal shock relations for a thermally perfect, calorically imperfect gas, modelling the vibrational excitation with an anharmonic oscillator model and including the influence of electronic modes, is derived and studied. Such additional considerations constitute an extension to the work achieved in the past, which modelled the caloric imperfections with a harmonic oscillator for vibrational energy and did not consider the effect of electronic energy. Additionally, the newly derived expressions provide physical insights into the limitations of experimentation for replicating flight conditions, which is demonstrated through providing solutions at different upstream temperatures. The results are compared with direct simulation Monte Carlo simulations for nitrogen and air, with the extent of the caloric imperfection of the gas showing excellent agreement. For low upstream temperatures, the extended relations are found to be in good agreement with the original normal shock wave expressions, but the results diverge for higher upstream temperatures that would be more representative of real flows. The results show that the new expressions depart from ideal gas theory for Mach numbers in excess of 4.9 at wind-tunnel conditions and for any Mach number above 3.0 at flight conditions. It is also shown that the traditional harmonic oscillator model and the anharmonic oscillator model begin to diverge at Mach number 3.0 for molecular oxygen gas and at Mach number 5.0 for an air mixture at flight conditions.\u0000</p></div>","PeriodicalId":775,"journal":{"name":"Shock Waves","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00193-023-01153-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140004907","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}