Shock Waves最新文献_第10页

Three-dimensional full-field simulation of sonic boom emanating from complex geometries over buildings 建筑物上空复杂几何形状声爆的三维全场模拟

IF 2.2 4区工程技术

Shock Waves Pub Date : 2023-04-12 DOI: 10.1007/s00193-023-01125-6

R. Yamashita, N. Nikiforakis

{"title":"Three-dimensional full-field simulation of sonic boom emanating from complex geometries over buildings","authors":"R. Yamashita, N. Nikiforakis","doi":"10.1007/s00193-023-01125-6","DOIUrl":"10.1007/s00193-023-01125-6","url":null,"abstract":"<div><p>Full-field direct simulation of sonic boom has only been applied to the analysis of axisymmetric geometries. In this work, a more realistic analysis of complex geometries over buildings is achieved by employing a combination of the following four numerical approaches: (i) a hierarchical structured adaptive mesh refinement method, (ii) a ghost fluid method for incorporating the immersed boundary conditions on the solid–fluid interfaces, (iii) a well-balanced finite volume method to allow stable stratification of the atmosphere, and (iv) a segmentation method of the computational domain to increase the efficiency of the computations. The three-dimensional Euler equations with a gravitational source term are solved over a stratified atmosphere. The simulation is split into two stages. Firstly, the entire flow field that involves a delta wing body is solved without buildings. Thereafter, the flow behaviors near the ground are recomputed considering rectangular and L-type buildings. Computational results show that the near- and far-fields waveforms are comparable to those from the wind tunnel experiment and the waveform parameter method, respectively. The waveform shape behind the shock waves is spiked due to the diffracted waves around buildings, with the spiking effect in L-type buildings being stronger than that in rectangular buildings. The pressure rises for rectangular and L-type buildings are significantly amplified due to double and triple reflections, respectively, each with an amplification factor comparable to the theoretical value. These results indicate that full-field simulation is promising for analyzing three-dimensional characteristics of sonic boom emanating from complex geometries passing over buildings.</p></div>","PeriodicalId":775,"journal":{"name":"Shock Waves","volume":"33 2","pages":"149 - 167"},"PeriodicalIF":2.2,"publicationDate":"2023-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00193-023-01125-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4484614","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}

引用次数: 0

On the effect of characterised initial conditions on the evolution of the mixing induced by the Richtmyer–Meshkov instability 论特征初始条件对由richmyer - meshkov不稳定性引起的混合演化的影响

IF 2.2 4区工程技术

Shock Waves Pub Date : 2023-04-12 DOI: 10.1007/s00193-023-01124-7

M. Rasteiro dos Santos, Y. Bury, S. Jamme, J. Griffond

{"title":"On the effect of characterised initial conditions on the evolution of the mixing induced by the Richtmyer–Meshkov instability","authors":"M. Rasteiro dos Santos, Y. Bury, S. Jamme, J. Griffond","doi":"10.1007/s00193-023-01124-7","DOIUrl":"10.1007/s00193-023-01124-7","url":null,"abstract":"<div><p>Time-resolved schlieren photography was used to visualise mixing zones induced by the Richtmyer–Meshkov instability. These were initiated with four different initial conditions: three of them with monotonic, single-mode shapes and one with a non-monotonic, multi-mode shape. These initial conditions were generated by an innovative experimental concept, the Micro Rotating Shutter System. The results of this experimental campaign reveal that the shape of the initial air–helium interface influences the subsequent development of the resulting mixing zone. Over the measurement time range, the width of the mixing zone induced by this instability is correctly fitted by a power law. Its growth exponent depends on the monotonicity of the initial air–helium interface: while mixing widths originating from single-mode initial conditions are almost superimposed, a lesser growth exponent is found for the multi-mode initial condition. The Reynolds number based on the width of the mixing zone suggests that both flows initiated with single- and multi-mode initial conditions reach a fully turbulent state after the interaction with the reflected shock wave (reshock). The schlieren photography visualisations presented here also allow to illustrate the structure of the induced mixing and highlight the effect of the initial conditions on the large-scale structures of the Richtmyer–Meshkov instability-induced mixing.\u0000</p></div>","PeriodicalId":775,"journal":{"name":"Shock Waves","volume":"33 2","pages":"117 - 130"},"PeriodicalIF":2.2,"publicationDate":"2023-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4484201","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}

引用次数: 0

Experimental results for 25-mm and 51-mm rotating detonation rocket engine combustors 25-mm和51-mm旋转爆轰火箭发动机燃烧室实验结果

IF 2.2 4区工程技术

Shock Waves Pub Date : 2023-04-12 DOI: 10.1007/s00193-023-01120-x

C. Knowlen, T. Mundt, M. Kurosaka

{"title":"Experimental results for 25-mm and 51-mm rotating detonation rocket engine combustors","authors":"C. Knowlen, T. Mundt, M. Kurosaka","doi":"10.1007/s00193-023-01120-x","DOIUrl":"10.1007/s00193-023-01120-x","url":null,"abstract":"<div><p>An ongoing rotating detonation rocket engine program is investigating the influence of combustor annulus radii on RDRE operating characteristics with flat-faced impinging injectors. To facilitate the isolation of all but the radius of curvature effects in the experiments, the annular gap was kept constant at 5 mm in combustors having either 25-mm or 51-mm outer diameter. The mixing processes were kept similar by utilizing injectors with the same net injector-to-annular gap area ratio (AR = 0.11), same radial separation distance of the orifices, and same center-of-gap impingement distance from the front-end wall. The wave dynamics, plenum pressure, and axial pressure profiles in these RDREs were compared over the mass flux and equivalence ratio ranges of <span>(80{-}400,text {kg/s/m}^{2})</span> and 0.26<span>(-)</span>2.6, respectively, with gaseous methane–oxygen propellant. Experiments showed that stable one-wave operation would occur in the 25-mm RDRE at most mass fluxes where stable two-wave operation was established in the 51-mm RDRE. Stable one-wave operation with a single counter-rotating wave was maintained in the 51-mm RDRE at mass fluxes of <span>(240,text {kg/s/m}^{2})</span> and below. Under these fueling conditions in the 25-mm RDRE, a counter-rotating wave also appeared while it operated with a single dominant wave. The wave spin speeds were typically 20–40% less than the Chapman–Jouguet detonation speed of the propellant and depended only on mass flux and wave number rather than the annulus diameter.</p></div>","PeriodicalId":775,"journal":{"name":"Shock Waves","volume":"33 3","pages":"237 - 252"},"PeriodicalIF":2.2,"publicationDate":"2023-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4484613","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}

引用次数: 0

Real gas effect on ignition in ideal and non-ideal reactors 理想和非理想反应器中实际气体对点火的影响

IF 2.2 4区工程技术

Shock Waves Pub Date : 2023-02-17 DOI: 10.1007/s00193-022-01118-x

I. Farias, Z. Weng, R. Mével

{"title":"Real gas effect on ignition in ideal and non-ideal reactors","authors":"I. Farias, Z. Weng, R. Mével","doi":"10.1007/s00193-022-01118-x","DOIUrl":"10.1007/s00193-022-01118-x","url":null,"abstract":"<div><p>We studied the real gas effect on the ignition characteristics in chemical reactors with one-step irreversible reaction. The real gas effects were characterized by the inter-molecular attraction term (<span>(alpha )</span>) and the finite molecular volume term (<span>(beta )</span>). The Noble-Abel and van der Waals equations of state were employed to derive non-dimensional reactor models. In addition to ideal reactors, i.e., constant volume and constant pressure, non-ideal reactors that account for the non-ideal pressure variation in shock tube and rapid compression machine were also considered. For all reactors, low value of <span>(alpha /beta )</span> and high value of <span>(beta )</span> (approximately <span>(alpha /beta <{{1.0}})</span> and <span>(beta >{{0.1}})</span>) induce a decrease of the ignition delay-time, while high value of both <span>(alpha /beta )</span> and <span>(beta )</span> (approximately <span>(alpha /beta >{{2.0}})</span> and <span>(beta >{{0.1}})</span>) induces an increase of the ignition delay-time. The variations of the ignition delay-time induced by real gas effects are mainly related to the change of the fugacity coefficient with <span>(alpha )</span> and <span>(beta )</span>. Additional contributions are due to the real gas heat capacity at constant pressure when considering a constant pressure reactor and to non-ideal volume variation when considering non-ideal reactors. The impact of various parameters was also investigated, including the heat capacity ratio of perfect gas, the reduced activation energy of the one-step reaction, and the heat content of the mixtures. Comparison with simulation performed with detailed reaction mechanisms and considering real gas models demonstrates that the present approach constitutes a rapid and simple, yet qualitatively or even quantitatively accurate method to assess the need of accounting for real gas effects to model chemical kinetics under high-pressure conditions.</p></div>","PeriodicalId":775,"journal":{"name":"Shock Waves","volume":"33 3","pages":"275 - 286"},"PeriodicalIF":2.2,"publicationDate":"2023-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00193-022-01118-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4971197","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}

引用次数: 1

Critical shock initiation characteristics of TNT with different charging types 不同装药类型TNT的临界起爆特性

IF 2.2 4区工程技术

Shock Waves Pub Date : 2023-02-06 DOI: 10.1007/s00193-022-01115-0

J. H. Wang, M. Xia, N. Jiang

{"title":"Critical shock initiation characteristics of TNT with different charging types","authors":"J. H. Wang, M. Xia, N. Jiang","doi":"10.1007/s00193-022-01115-0","DOIUrl":"10.1007/s00193-022-01115-0","url":null,"abstract":"<div><p>To study the shock wave initiation characteristics of 2,4,6-trinitrotoluene (TNT) under different charging types, the shock wave pressure and shock wave attenuation of standard Pentolite explosives under different diaphragm thicknesses were quantitatively studied using the ion probe method. The gap tests of three explosives were carried out, including pressed TNT without restraint, pressed TNT with steel pipe restraint, and cast TNT with steel pipe restraint. The shock wave initiation pressures of TNT under the three different conditions were compared. Moreover, combined with the numerical simulation technology, the critical initiation pressure and the pressure cloud diagram of the gap test of TNT were obtained, and the dynamic change process of the shock wave in the diaphragm was acquired, which was difficult to measure in the experiments. The results showed that the critical initiation pressure of pressed TNT was significantly lower than that of cast TNT and that restraint can reduce the measured critical initiation pressure of TNT under certain conditions. Therefore, the research results may provide a basis for the damage range of TNTs with different charging types and the determination of the safety protection distance of shock wave initiation.</p></div>","PeriodicalId":775,"journal":{"name":"Shock Waves","volume":"33 1","pages":"39 - 49"},"PeriodicalIF":2.2,"publicationDate":"2023-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4575208","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}

引用次数: 1

Propagation characteristics of blast shock waves in low-pressure environment 爆炸冲击波在低压环境下的传播特性

IF 2.2 4区工程技术

Shock Waves Pub Date : 2023-02-06 DOI: 10.1007/s00193-022-01116-z

L. Chen, Z. Li, R. Chen, F. Lu

{"title":"Propagation characteristics of blast shock waves in low-pressure environment","authors":"L. Chen, Z. Li, R. Chen, F. Lu","doi":"10.1007/s00193-022-01116-z","DOIUrl":"10.1007/s00193-022-01116-z","url":null,"abstract":"<div><p>The blast loading from a detonation of a high explosive charge at high altitude is quite different from that at sea level. Due to diminished ambient pressure, the damage caused by the blast load may be more minor at high altitude. However, the shock wave parameters at diminished ambient pressure have not yet been thoroughly studied. In this research, experiments were carried out to study the relation between ambient air pressure and shock wave parameters. The explosion experiments were carried out in a sealed explosion chamber with an initial pressure of 95 kPa, 74 kPa, and 57 kPa. For these three atmospheric conditions, the history profiles of incident shock wave pressure generated by TNT charges of 106 g and 292 g were recorded. The influence of ambient pressure and temperature on the shock wave parameters was analyzed through numerical simulations. By analyzing the experimental and numerical data, it was found that ambient pressure is the main factor affecting the shock wave parameters, while the effect of temperature is not so obvious. Furthermore, based on the analysis of experimental data, formulas for evaluating shock wave overpressure, specific impulse, and arrival time using the Sachs variables are given, and the shock wave parameters at an altitude of 5000 m are calculated using these formulas. The observed maximum reduction in the shock wave overpressure was 23%, in specific impulse 27%, and in arrival time 12%, compared to the results calculated at sea level. The results can be applied to blast-resistant analyses of buildings in low-pressure environment.</p></div>","PeriodicalId":775,"journal":{"name":"Shock Waves","volume":"33 1","pages":"61 - 74"},"PeriodicalIF":2.2,"publicationDate":"2023-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4245320","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}

引用次数: 1

Flow acceleration in an RDRE with gradual chamber constriction 腔室逐渐收缩时rdrre中的流动加速度

IF 2.2 4区工程技术

Shock Waves Pub Date : 2023-02-06 DOI: 10.1007/s00193-022-01117-y

M. Ross, J. Burr, Y. Desai, A. Batista, C. Lietz

{"title":"Flow acceleration in an RDRE with gradual chamber constriction","authors":"M. Ross, J. Burr, Y. Desai, A. Batista, C. Lietz","doi":"10.1007/s00193-022-01117-y","DOIUrl":"10.1007/s00193-022-01117-y","url":null,"abstract":"<div><p>Rotating detonation propulsion technologies have the potential to create highly efficient engines in a small form factor. However, the detonation dynamics and complex flowfields inside the combustion chamber are greatly dependent on geometry; in particular, the downstream nozzle design affects dynamics inside the combustion chamber. In this work, three-dimensional large eddy simulations of a gaseous methane–oxygen rotating detonation rocket engine are presented for two geometries. The geometries match experimental tests previously conducted at the Air Force Research Laboratory and are chosen to compare engine operation with and without a converging–diverging nozzle. It is shown that flow in the unconstricted chamber exceeds Mach 1 behind the generated oblique shock structure, but that the addition of a 4.4<span>(^circ )</span> converging section results in supersonic flow existing only in the diverging section of the nozzle. The formation enthalpy of the flow is calculated inside the chamber and demonstrates that the difference in pressures and detonation structures associated with the chamber area constriction do not result in a significant change in energy released through combustion.</p></div>","PeriodicalId":775,"journal":{"name":"Shock Waves","volume":"33 3","pages":"253 - 265"},"PeriodicalIF":2.2,"publicationDate":"2023-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00193-022-01117-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4249604","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}

引用次数: 1

Effects of ozone addition and LTC progression on detonation of O(_{3})-enhanced DME–O(_{2}) 臭氧添加和LTC进程对O (_{3}) -增强DME-O爆轰的影响(_{2})

IF 2.2 4区工程技术

Shock Waves Pub Date : 2023-01-13 DOI: 10.1007/s00193-022-01113-2

M. C. Brown, E. L. Belmont

{"title":"Effects of ozone addition and LTC progression on detonation of O(_{3})-enhanced DME–O(_{2})","authors":"M. C. Brown, E. L. Belmont","doi":"10.1007/s00193-022-01113-2","DOIUrl":"10.1007/s00193-022-01113-2","url":null,"abstract":"<div><p>The effects of ozone addition and low-temperature chemistry (LTC) progression on DME/O<span>(_{2})</span> detonations are evaluated with experimental detonation velocity and cell size measurements and one-dimensional ZND simulations. For <span>( phi = 1.2)</span> and <span>(P_{textrm{o}}= 22.7)</span> kPa, detonations are experimentally investigated over a range of ozone enhancement levels (0.0–1.6-mol%), initial reactant temperatures (293 K and 468 K), and LTC progression times (250–6000 ms). A 33-K gas temperature rise from LTC heat release is observed for mixtures with 1.0-mol% ozone enhancement and initial temperature of 468 K, suggesting a limited extent of LTC progression in this study. Experiments showed minimal detonation velocity dependence on ozone enhancement level or LTC progression despite the increased radical pool. Average cell size is found to decrease 15–30% with 1.6-mol% ozone addition, indicating a greater reactant mixture sensitivity to detonation. To estimate the cell size, a center-of-exothermic-length induction length is defined and used with an empirical correlation to calculate a singular cell size when multiple thermicity peaks are present in ZND modeling. This approach shows good agreement with experimental findings. Cell size dependence on LTC progression is found to have a statistically insignificant variance for LTC progression times at the temperatures used in this study.\u0000</p></div>","PeriodicalId":775,"journal":{"name":"Shock Waves","volume":"33 1","pages":"21 - 37"},"PeriodicalIF":2.2,"publicationDate":"2023-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4535663","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}

引用次数: 1

Atomville: Architects, Planners, and How to Survive the Bomb. Atomville:建筑师，规划师，以及如何在炸弹中生存

IF 1.7 4区工程技术

Shock Waves Pub Date : 2023-01-01 DOI: 10.1353/tech.2023.a903974

Arthur Molella, Robert Kargon

引用次数: 0

Study on the factors influencing the interaction and coalescence of shock waves from multiple explosion sources in free field 自由场多爆炸源激波相互作用与聚并的影响因素研究

IF 2.2 4区工程技术

Shock Waves Pub Date : 2022-12-28 DOI: 10.1007/s00193-022-01111-4

S. Y. Wang, J. L. Qiu, Y. W. Wang, J. W. Jiang

{"title":"Study on the factors influencing the interaction and coalescence of shock waves from multiple explosion sources in free field","authors":"S. Y. Wang, J. L. Qiu, Y. W. Wang, J. W. Jiang","doi":"10.1007/s00193-022-01111-4","DOIUrl":"10.1007/s00193-022-01111-4","url":null,"abstract":"<div><p>The interaction and coalescence of shock waves originating from multiple explosion sources were studied using numerical simulations and theoretical analysis. The effects of the mass distribution, layout, and quantity of explosion sources were considered, and an engineering calculation model for shock wave parameters at the focus center was established. The results show that the peak overpressure at the focus center is significantly changed only when the mass ratio of the two explosion sources increases beyond two. Overall, the peak overpressure at the focus center decreases with the increase in mass ratio. The focus effect of multiple explosion sources is the greatest when the sources are uniformly distributed on a circle. When the number of explosion sources is less than four, the peak overpressure and specific impulse at the focus center increase with the increase of the number of explosion sources. Increasing the number of explosion sources from one to four results in an increase in the peak overpressure by a factor of 0.73–5.23 and an increase in the specific impulse gain by a factor of 1.59–4.71. The results from simulations and experiments verify the validity of the model used to characterize multiple explosion sources.\u0000</p></div>","PeriodicalId":775,"journal":{"name":"Shock Waves","volume":"33 1","pages":"51 - 60"},"PeriodicalIF":2.2,"publicationDate":"2022-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"5078899","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}

引用次数: 0