Shock Waves最新文献

{"title":"Single- and two-phase fluid droplet breakup in impulsively generated high-speed flow","authors":"J. Leung,&nbsp;M. Gurunadhan,&nbsp;S. Menon","doi":"10.1007/s00193-023-01145-2","DOIUrl":"10.1007/s00193-023-01145-2","url":null,"abstract":"<div><p>Aerobreakup of fluid droplets under the influence of impulsively generated high-speed gas flow using an open-ended shock tube is studied using experiments and numerical simulations. Breakup of millimeter-sized droplets at high Weber numbers was analyzed for water and two-phase nanofluids consisting of dispersions of <span>({{hbox {Al}}_{2}{hbox {O}}_{3}})</span> and <span>({{hbox {TiO}}_{2}})</span> nanoparticles in water with high loading of 20 and 40 wt%, respectively. Droplet breakup is visualized using high-speed imaging in the experimental setup, where an open-ended shock tube generates impulsive high-speed flow impinging on a droplet held stationary using an acoustic levitator. Axisymmetric simulations using the volume-of-fluid technique are conducted to capture the gas dynamics of the flowfield and droplet deformation at the initial stages. Fluid droplets are subject to a transient flowfield generated by the open-ended shock tube, characterized by a propagating incident shock wave, a recirculating vortex ring, and standing shock cells. Droplet breakup for all fluids proceeds through an initial flattening of the droplet followed by generation of a liquid sheet at the periphery in the presence of a curved detached shock front at the leading edge. The breakup appears to follow a sheet stripping process whereby stretched ligaments undergo secondary atomization through viscous shear. Mist generated in the wake of the droplet appears to expand laterally due to the unconstrained expansion of the high-speed gas jet. The breakup morphology of droplets for all fluids appears consistent with previous observations using conventional shock tubes. Lateral deformation of the coherent droplet mass is observed to be higher for nanofluids as compared to water. This is attributed to higher viscosity and Ohnesorge number of nanofluid droplets, which results in delayed breakup and increased lateral stretching. When plotted as a function of non-dimensionalized time, the same effects are also attributed to generate the highest non-dimensional velocities for the <span>({{hbox {TiO}}_{2}})</span> nanofluid, followed by <span>({{hbox {Al}}_{2}{hbox {O}}_{3}})</span> nanofluid, and water, which mirrors the order of viscosity and Ohnesorge number for the three fluids. An area of spread, which can be interpreted as a measure of dispersion, plotted as a function of non-dimensionalized time also shows the highest value for the <span>({{hbox {TiO}}_{2}})</span> nanofluid, followed by <span>({{hbox {Al}}_{2}{hbox {O}}_{3}})</span> nanofluid, and water. Overall, current results indicate that droplet breakup for two-phase fluids appears to be similar to those for single-phase fluids with effectively higher viscosity. Furthermore, an open-ended shock tube proves to be an effective tool to study droplet aerobreakup, with some differences observed in the droplet wake due to the unconfined expansion of gas flow.</p></div>","PeriodicalId":775,"journal":{"name":"Shock Waves","volume":"33 5","pages":"385 - 399"},"PeriodicalIF":2.2,"publicationDate":"2023-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"6713799","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":"Dual behavior of hydrogen peroxide in gaseous detonations","authors":"A. Dahake,&nbsp;R. K. Singh,&nbsp;A. V. Singh","doi":"10.1007/s00193-023-01142-5","DOIUrl":"10.1007/s00193-023-01142-5","url":null,"abstract":"<div><p>The paper describes the dual behavior observed for hydrogen peroxide when added to hydrogen-air detonating mixtures. The effect of the addition of hydrogen peroxide on <span>(text {NO}_{x})</span> emissions and critical detonation parameters was evaluated for <span>(text {H}_{2})</span> air mixtures using one-dimensional ZND calculations. Hydrogen peroxide acts as an ignition promoter and is shown to significantly enhance the detonation chemistry when added in small concentrations. It alters the ignition chemistry of an underlying detonation wave without affecting the bulk thermodynamic properties. The main objective of the present study is to evaluate the ignition promotion and <span>(text {NO}_{x})</span> mitigation effects of hydrogen peroxide in gaseous detonations when it is added to hydrogen-air mixtures in small and large concentrations. In the current work, the diminishing sensitizing potential of hydrogen peroxide when added in large amounts (up to 10%) is also reported. The results show a visible effect on ignition promotion up to 20,000 ppm. At concentrations higher than 20,000 ppm of <span>(text {H}_{2}text {O}_{2})</span>, further reduction in the induction length was found to be minimal. The <span>(text {NO}_{x})</span> emissions were found to decrease for stoichiometric and fuel-lean <span>(text {H}_{2})</span>-air mixtures, whereas the <span>(text {NO}_{x})</span> concentration was found to increase for fuel-rich mixtures with the addition of hydrogen peroxide. Thus, the dual behavior exhibited by <span>(text {H}_{2}text {O}_{2})</span> is shown to be advantageous as it could potentially mitigate <span>(text {NO}_{x})</span> emissions at high temperatures for fuel-lean and stoichiometric hydrogen-air mixtures and, at the same time, could sensitize the given mixture for applications in detonation-based combustors.</p></div>","PeriodicalId":775,"journal":{"name":"Shock Waves","volume":"33 5","pages":"401 - 414"},"PeriodicalIF":2.2,"publicationDate":"2023-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"6713798","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":"Drag and rolling moment measurements using accelerometer-based force balance in a shock tunnel","authors":"B. Jang,&nbsp;K. Kim,&nbsp;G. Park","doi":"10.1007/s00193-023-01143-4","DOIUrl":"10.1007/s00193-023-01143-4","url":null,"abstract":"<div><p>A multicomponent force balance was designed to measure the drag and rolling moment using an accelerometer-based technique. The force balance system used a linear ball bush as a new model mount system to minimize the constraint of the test model motion in both the axial and rotational directions. The accelerations of the test model were measured in the axial and rotational directions using accelerometers that were externally mounted on the test model. The drag and rolling moment were recovered from the measured accelerations using the system response functions, which included the dynamic characteristics of the force balance system. The system response functions were determined from the force balance calibration processes by applying a series of point loads in the axial and rotational directions and deconvolving the resulting accelerations. The drag and rolling moment measurements on the wedge model, including the flaps, were performed in a shock tunnel with a test time of approximately 3 ms at a nominal freestream Mach number of 6. A computational fluid dynamics (CFD) analysis assuming a laminar boundary layer was performed. Good agreement was obtained between the measured and calculated results. An uncertainty analysis of the measurements was conducted with regard to the influence of the fundamental properties of the test condition and force balance system.</p></div>","PeriodicalId":775,"journal":{"name":"Shock Waves","volume":"33 5","pages":"415 - 427"},"PeriodicalIF":2.2,"publicationDate":"2023-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"6713793","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 investigation of the interaction between a water droplet and a shock wave above Mach 4","authors":"F. Virot,&nbsp;G. Tymen,&nbsp;D. Hébert,&nbsp;J.-L. Rullier,&nbsp;E. Lescoute","doi":"10.1007/s00193-023-01139-0","DOIUrl":"10.1007/s00193-023-01139-0","url":null,"abstract":"<div><p>Experimental results on the interactions between a single water droplet and a shock wave propagating at Mach number above 4 are presented in this paper. A detonation-driven shock-tube test facility is used to work within a Mach range at <span>({M}=4.3)</span> (high-supersonic regime) and <span>({M}=10.6)</span> (hypersonic regime), for which the maximum studied dimensionless times <i>T</i> are up to 9.4 and 5.5, respectively. For both Mach ranges, the initial droplet diameters typically vary between 430 and 860 <span>(upmu hbox {m})</span> and the associated Weber numbers vary from <span>(5 times 10^{4})</span> to <span>(11 times 10^{4})</span>. Ultra-high-speed cameras are used to record the evolution of the water droplet when the shock wave impacts it. Until <span>({T} approx 2.5)</span>, the qualitative and quantitative analyses of our frames show that the initial diameter as well as the Mach number studied have an apparent weak influence on the droplet dimensionless displacement. Beyond this time, the results for <span>({M}=10.6)</span> are more dispersed than the data for <span>({M}=4.3)</span> revealing a possible effect of the droplet size. One of the main results of this paper is that the droplet disappearance occurs at <span>({T}=[4.5)</span>–5.5] for <span>({M}=10.6)</span>, while some mist is still present at <span>({T}&gt;9)</span> for <span>({M}=4.3)</span>. We note also that the droplet is always supersonic for <span>({M}=10.6)</span> whereas it becomes subsonic at <span>({T}approx 3.5)</span> for <span>({M}=4.3)</span>.</p></div>","PeriodicalId":775,"journal":{"name":"Shock Waves","volume":"33 5","pages":"369 - 383"},"PeriodicalIF":2.2,"publicationDate":"2023-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"6713769","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":"Development of governing equations for mixing shocks in two-phase flows","authors":"M. Mollakouchakian,&nbsp;M. D. Emami","doi":"10.1007/s00193-023-01140-7","DOIUrl":"10.1007/s00193-023-01140-7","url":null,"abstract":"<div><p>An important phenomenon in the gas–liquid two-phase mixtures is a sudden change in the flow that may lead to transition of the flow regime from non-homogeneous slip flow to homogenous flow. This phenomenon is called <i>mixing shock</i> and has been investigated by several researchers. In the present paper, a more comprehensive model is proposed by including the entrainment ratio in the governing equations. Moreover, parametric studies are performed to assess the importance of this parameter in different conditions. The results of the present study indicate that at Euler numbers less than four the effect of gas mass flow is insignificant. However, at higher Euler numbers the differences of the present and previous models are noticeable. Since two possible solutions for the aftershock state exist, four criteria—entropy change across the shock, possibility of an expansion shock, positivity of the Euler number, and choking flow condition—are considered to identify the correct solution. The results indicate that the flow after the shock could only be of a subsonic type, and the mixing shock is compressive. A comparison of the possible realizable zones for the developed model and the previous models indicates that the developed model predicts a larger area for the realizable solution of the mixing shock. A comparison between analytical results and experimental data shows that the developed model predicts reasonable results.</p></div>","PeriodicalId":775,"journal":{"name":"Shock Waves","volume":"33 4","pages":"357 - 368"},"PeriodicalIF":2.2,"publicationDate":"2023-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4938431","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":"Multiple elastic shock waves in cubic single crystals","authors":"Q. Liu,&nbsp;Y. F. Xu,&nbsp;S. C. Hu,&nbsp;Y. X. Li,&nbsp;Y. Cai,&nbsp;S. N. Luo","doi":"10.1007/s00193-023-01137-2","DOIUrl":"10.1007/s00193-023-01137-2","url":null,"abstract":"<div><p>Multiple elastic shock waves carry the information on elastic properties under dynamic extreme conditions, but may complicate the interpretation of wave structure including the elastic–plastic transition. On the basis of the acoustic wave-equation analysis, we predict the absence or presence of multiple elastic shock waves in a single crystal subjected to shock loading along a specific crystallographic orientation. Typical FCC and BCC single crystals are taken as validation and application cases. Large-scale molecular dynamics simulations are performed for Cu and Ta; double-wave or triple-wave structures of elastic shock waves (quasilongitudinal and quasitransverse) are observed in the simulations, and the multi-wave structures are in excellent agreement with the wave-equation analysis. Also, the acoustic wave-equation analysis is used to analyze MD calculations, as well as the complex structure of the shock wave during plastic deformation. Free-surface velocity history, transverse velocity history of free surface, and ultrafast X-ray diffraction are explored as experimental means to resolve multiple elastic shock waves.</p></div>","PeriodicalId":775,"journal":{"name":"Shock Waves","volume":"33 4","pages":"337 - 355"},"PeriodicalIF":2.2,"publicationDate":"2023-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00193-023-01137-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"5008683","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":"Towards laser-induced fluorescence of nitric oxide in detonation","authors":"K. P. Chatelain,&nbsp;S. B. Rojas Chavez,&nbsp;J. Vargas,&nbsp;D. A. Lacoste","doi":"10.1007/s00193-023-01134-5","DOIUrl":"10.1007/s00193-023-01134-5","url":null,"abstract":"<div><p>This study aims to validate the new developments in our in-house spectroscopic code (KAT-LIF) to perform NO-LIF simulations for detonation conditions, as well as evaluating the capabilities of the NO-LIF diagnostic for characterizing H<span>(_2)</span>-air detonations. This objective was achieved in several steps. First, our in-house spectroscopic tool, KAT-LIF, was updated to perform NO-LIF simulations by notably developing a database of NO(A-X) transitions, currently unavailable in conventional spectroscopic databases, as well as collecting and implementing species-specific line broadening, line shifting, and quenching parameters for NO-LIF. Second, the validation of KAT-LIF was performed by comparing the simulation results with pre-existing simulation tools (LIFSim and LIFBASE) and experimental NO-LIF measurements in a laminar CH<span>(_4)</span>-air flame and H<span>(_2)</span>-air detonation. The validation results present satisfactory agreement of KAT-LIF and other simulation tools (LIFBASE, LIFSim) with experimental results for several conditions. For example, less than 20% discrepancy between the simulated and experimental NO-LIF profiles is observed for stoichiometric H<span>(_2)</span>-air detonation, initially at 20 kPa and 293 K. Third, qualitative and quantitative capabilities of the NO-LIF technique for detonation characterization are discussed, which include: shock detection, induction zone length measurements, and quantitative number density measurements.</p></div>","PeriodicalId":775,"journal":{"name":"Shock Waves","volume":"33 3","pages":"179 - 189"},"PeriodicalIF":2.2,"publicationDate":"2023-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4759297","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 two-scale approach to widen a predictive blast propagation model around a hemicylindrical obstacle","authors":"R. Gavart,&nbsp;S. Trélat,&nbsp;M.-O. Sturtzer,&nbsp;N. Chaumeix","doi":"10.1007/s00193-023-01135-4","DOIUrl":"10.1007/s00193-023-01135-4","url":null,"abstract":"<div><p>The aim of the present paper was to report on an experimental study of the characterization of a blast wave initiated by a solid explosive and its interaction with a rigid obstacle in the form of a hemicylinder. Pressure transducers located along the path of the blast wave and high-speed imaging allow (1) the measurement of the overpressure at different locations and (2) the characterization of the blast wave inception, propagation, and reflection off the hemicylinder. The scaling effect has been investigated by performing experiments in two different facilities, where one is at twice the scale of the other.\u0000</p></div>","PeriodicalId":775,"journal":{"name":"Shock Waves","volume":"33 3","pages":"287 - 297"},"PeriodicalIF":2.2,"publicationDate":"2023-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00193-023-01135-4.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4942725","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":"Selected topics from the 28th International Colloquium on the Dynamics of Explosions and Reactive Systems, Naples, Italy, June 19–24, 2022","authors":"G. Ciccarelli","doi":"10.1007/s00193-023-01138-1","DOIUrl":"10.1007/s00193-023-01138-1","url":null,"abstract":"","PeriodicalId":775,"journal":{"name":"Shock Waves","volume":"33 3","pages":"177 - 177"},"PeriodicalIF":2.2,"publicationDate":"2023-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00193-023-01138-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4627805","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":"Operation characteristics of a disk-type rotating detonation engine","authors":"K. Ishii,&nbsp;K. Ohno,&nbsp;H. Kawana,&nbsp;K. Kawasaki,&nbsp;A. K. Hayashi,&nbsp;N. Tsuboi","doi":"10.1007/s00193-023-01133-6","DOIUrl":"10.1007/s00193-023-01133-6","url":null,"abstract":"<div><p>In the present work, operation characteristics of a disk-type rotating detonation engine (DRDE) with a constant chamber area were experimentally studied for various total mass flow rates and a wide variety of equivalence ratios of hydrogen–air mixtures. From the direct visualizations, the rotating detonation wave was found to propagate near the outer wall of the combustion chamber, regardless of the wave mode. For the present test conditions, single- and double-wave modes are observed, depending on the equivalence ratio of the mixture. The pressure gain was evaluated based on a one-dimensional flow model together with the chamber static pressure measured with the capillary tube average pressure technique. Although the present DRDE configuration provided a negative pressure gain for all the test conditions, it was found that the single-wave mode was superior to the double-wave mode in terms of the pressure gain.</p></div>","PeriodicalId":775,"journal":{"name":"Shock Waves","volume":"33 3","pages":"267 - 274"},"PeriodicalIF":2.2,"publicationDate":"2023-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00193-023-01133-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"5054459","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}