bluuebunny/crossref_metadata_2025_split huggingface dataset:
Supercritical and transcritical real-fluid mixing using the PC-SAFT EOS
Authors: Rodriguez Carlos , Vidal Alvaro , Koukouvinis Phoevos , Gavaises Manolis 
Published: September 2017

A numerical framework has been developed to simulate the mixing of supercritical and transcritical fluids using anequation of state based on statistical associating fluid theory. In a Diesel engine the liquid fuel is injected into supercritical air. After the injection, the Diesel is heated over its critical temperature reaching a supercritical state. Modelling real-fluid effects is critical in order to properly characterize the air/fuel mixing in the combustion chamber. By using the PC-SAFT EoS (Perturbed Chain Statistical Association Fluid Theory Equation of State) real fluids effects can be taken into account in a CFD simulation. The PC-SAFT EoS shows best results than cubic EoS computing liquid density, compressibility, speed of sound, vapor pressures and density derivatives. Unlike cubic EoS, this model accounts for the shape and size of the molecules. Gas, liquid, supercritical and vapor-liquid equilibrium states can be simulated. PT FLASH (Isothermal Multiphase Flash Calculation) is applied to compute the phase diagram used by the code. Shock tube problems were conducted in a wide range of pressures and densities using n-dodecane to show the capability of the developed algorithm. The results were compared with the solution of an exact Riemann solver which has the PC-SAFT EoS implemented showing a high degree of agreement. In addition, a two-dimensional simulation of supercritical nitrogen jet mixing was carried out to checkthe multidimensional capability of the code.DOI: http://dx.doi.org/10.4995/ILASS2017.2017.5000
Analysis of PDA measurements in double injection GDI sprays
Authors: Araneo Lucio , Dondè Robert , Postrioti Lucio , Cavicchi Andrea 
Published: September 2017

A N-heptane spray from a GDI multi-hole injector operated in ambient air at fixed conditions and with doubleinjection commands is studied with different experimental techniques to better understand the spray behaviors, focusing the analysis on the effect of different dwell times between the two pulses. Results from spray photographic analysis, fuel injected quantity, droplet velocity and sizing by Phase Doppler Anemometry are presented and compared. The peculiarities and usefulness of a complementary application of the different techniques is illustrated. The two spray pulses have the same time length, so that the first spray evolves in a nearly quiescent and clean ambient, while the second, nominally identical to the first one, evolves in its trailing edge. The direct comparison allows an immediate perception of the differences among the two sprays, at the different dwell times, where the shorter tested, 160 microseconds, was chosen as the one that shows the first appreciable effect with at least one of the used techniques; the differences are clearly evident in the PDA results, sufficiently visible from the injection rate, not appreciable in the imaging at short distance. The effect of the longerdwell times becomes more evident and is illustrated.DOI: http://dx.doi.org/10.4995/ILASS2017.2017.5007
Time resolved thermographic analysis of droplet impacts onto heated surfaces under extreme wetting scenarios
Authors: Moita Ana Sofia , Pontes Pedro , Teodori Emanuele , Moreira António Luís Nobre 
Published: September 2017

The present paper explores the use of time resolved infrared IR thermography combined with high-speed imagingto describe the liquid-surface interfacial heat transfer phenomena occurring at droplet/wall interactions. Custom made calibration and post-processing methods are proposed and discussed. The results show that the methodology proposed captures very well particular details on droplet dynamics and heat transfer, allowing to identify air bubble trapping at the impact region as well as the temperature variations at the formation of the rim. Furthermore, the calibration proposed here allowed amending some physically incorrect results that were often obtained with the IR camera’s default calibration. The combined analysis of droplet dynamics (e.g. the spreading factor) with the radial temperature profiles, heat flux and cooling effectiveness computation allowed establishing qualitative and quantitative trends on the effect of various parameters on the heat transfer occurring at droplet/wall interactions. Particularly, the effect of the initial surface temperature is observed to play a minor role, as long as it is low enough to prevent the occurrence of boiling. On the other hand, extreme wetting scenarios, such as superhydrophobicity limit the heat transfer between the spreading droplet and the surface. However, the thermal analysis reveals that a major reason for this is not related to the reduced contact time of the droplet on the surface (due to rebound) or air entrapment, but is rather associated to the reduced wetted area caused by thehigh contact angles.DOI: http://dx.doi.org/10.4995/ILASS2017.2017.5012
Towards Resolving the Atomization Process of an Idealized Fire Sprinkler with VOF Modeling
Authors: Meredith Karl Virgil , Zhou X. , Wang Y. 
Published: September 2017

Fire suppression modeling depends on accurate characterization of the atomization processes of fire sprinklers.Numerical modeling, particularly the volume of fluid (VOF) method, has been applied to understanding the atomization behavior of an idealized sprinkler geometry consisting of a 9.5 mm inner-diameter cylindrical nozzle and a flat, 25.4 mm diameter disk with a liquid flow rate of 0.87 L/s. The simulations have been performed with an OpenFOAM based VOF solver, using the isoAdvector scheme for interfacial reconstruction. The sheet breakup distance and film thickness were calculated and compared with measurements from a previous study. A mesh refinement study identified the sensitivities in the predicted quantities to mesh resolution. This study enables furtherapplication of the model to simulation of the fully atomized spray.DOI: http://dx.doi.org/10.4995/ILASS2017.2017.5014
Imaging of gasoline-like sprays with planar laser-induced exciplex fluorescence using a stereoscopic imaging system
Authors: Andersson Mats , Yamaguchi Akichika , Wang Hua 
Published: September 2017

The role of the fuel injection systems in direct injected gasoline engines is to achieve a suitable fuel vapordistribution, homogeneous or with some degree of stratification, while avoiding unwanted effects such as wall wetting. Planar laser-induced exciplex fluorescence (PLIEF) is a method suitable for the characterization of such sprays since it enables separate imaging of both vapor and liquid phase of fuel simultaneously. In this study a hollow-cone spray generated with an outwards-opening piezo-actuated injector is investigated, with the injector mounted in a constant volume, constant pressure spray chamber with quartz windows, providing a controlled steady test environment. N-hexane is used as surrogate fuel of gasoline, together with exciplex-forming fluorescence tracers - fluorobenzene and diethylmethylamine. Fluorescence excitation is carried out with a parallel laser sheet from the fourth harmonic light of a Nd:YAG-laser (266 nm) running at 10 Hz. Exciplex fluorescence images from liquid phase and monomer fluorescence spray images from vapor phase can be acquired by a single UV-sensitive CMOS camera equipped with a stereoscope having filters selectively transmitting monomer fluorescence at 295 nm and exciplex fluorescence at 355 nm. Since the fluorescence is strongly quenched by oxygen, most of the experiments were carried out in a nitrogen atmosphere.Images were recorded during the injection and at various time steps after the end of the injection, and typical spray development for this type of injector was observed, i.e. the fuel forms an expanding cone, the sheet breaks up to form a vortex structure and the vortices continue to expand after the end of the injection. Fuel vapor is firstly observed at the same locations as the liquid drops, and is then accumulated into the center of the vortices. In addition, penetration of liquid phase and vapor phase are found to be very similar. Various injection pressures have been tested, which shows that increasing the fuel pressure from 10 to 20 MPa results in a larger vortex structure. The fuel evaporation can be followed by studying the evolution of the monomer and exciplex fluorescence as a function of time. At room temperature the vaporization is found to be very slow, but above 40°C there is a noticeablepresence of vapor at the end of the injection, and at higher temperatures, the vaporization goes even faster.DOI: http://dx.doi.org/10.4995/ILASS2017.2017.5023
Influence of Stokes Number on Collisional Interfacial Area Production Terms within the Σ-Y Eulerian Spray Atomization Model
Authors: Eichler Dominik , Pischke Philipp , Kneer Reinhold 
Published: September 2017

The present study shows the effects of Stokes number on the modeling of collisional interfacial area productionterms within the Σ-Y model. This model can be employed for CFD simulations of high Weber and Reynolds number sprays using a RANS turbulence modeling. Within the model production of interfacial area is assumed to result from turbulent stretching and turbulent droplet collisions. The modeling of collisional processes requires the calculation of a characteristic turbulent collision velocity. In the present work this velocity was determined under consideration of Stokes number effects leading to turbulent droplet velocity fluctuations attenuated with respect to the gas phase fluctuations and including partial correlation between the velocities. The influence of this new modeling approach is tested within a 2D spray simulation by comparing the Sauter mean diameters observed to the ones obtained by employing the modeling approaches proposed in the literature which do not consider any Stokes number effects.The reduced collision velocites in the new modeling lead to higher values for Sauter mean diameters in the spray.DOI: http://dx.doi.org/10.4995/ILASS2017.2017.5041
Evidence of vortex driven primary breakup in high pressure fuel injection
Authors: Shi Junmei , Aguado Lopez Pablo , Gomez Santos Eduardo , Guerrassi Noureddine , Dober Gavin , Bauer Wolfgang , Lai Ming-Chia , Wang Jin 
Published: September 2017

This paper is to present a detailed case study on how the nozzle flow dynamics influences the primary breakup inthe spray formation process of diesel injection. The investigation was based on a 3-hole real-application nozzle with highly tapered injection holes using a URANS-LES (Large Eddy Simulation) hybrid approach in combination with the coupled Volume of Fluid (VOF) and Level Set method. High resolution LES was applied to simultaneously resolve the multi-scale nozzle flow dynamics downstream of the needle seat and the primary breakup process in the near-nozzle spray. Phase Contrast X-ray imaging (PCX) was applied to characterize the liquid-gas interfaces in the near-nozzle spray for validation purposes. The results provide detailed information on how the vortex shedding and vortex interactions in the injection hole drives the jet deformation, ligament anddroplet formation in the primary breakup process.DOI: http://dx.doi.org/10.4995/ILASS2017.2017.5707
Dilute polymer solution drops impacting on heated surfaces: New impact morphologies and impact regime maps
Authors: Bertola Volfango , Lakhanpal Chetan 
Published: September 2017

The impact morphology of dilute polymer solution drops on a heated surface is studied experimentally by meansof high-speed imaging, with respect to the following parameters: surface temperature; impact Weber number; polymer concentration; polymer molecular weight. In addition to impact morphologies observed in Newtonian drops (deposition, rebound, secondary atomisation and breakup/splashing), three new impact regimes have been identified: (i) a single satellite droplet ejected in the direction of bouncing but tethered to the main drop by a thin liquid filament; (ii) a splashing-like behaviour (semi-splashing), where the rim instability generates satellite droplets tethered to the lamella by thin liquid filaments; (iii) a spray-like behaviour (semi-spray), where a fine secondary atomisation generated upon impact is quickly absorbed back into the drop globule. Experiments were carried out using drops of aqueous polyethylene oxide (PEO) solutions, with mass concentrations of 100 ppm, 200 ppm and 400 ppm, and PEO molecular weights of 2 MDa, 4MDa, and 8MDa. The impact morphology on a polished aluminium surface with temperatures ranging between 160°C and 400°C was investigated for impact Weber numbers between 20 and 170, taking side view images of impacting drops at a rate of 1,000 frames persecond.DOI: http://dx.doi.org/10.4995/ILASS2017.2017.4905
The genesis of Hurricane Nate and its interaction with a nearby environment of very dry air
Authors: Rutherford Blake , Dunkerton Timothy , Montgomery Michael , Braun Scott 
Published: September 2017

Abstract. The interaction of a tropical disturbance with its environment is thought to play an important role in whether a disturbance will develop or not. Most developing disturbances are somewhat protected from the intrusion of environmental dry air at mid-levels. For African easterly wave (AEW) disturbances, the protective boundary is approximated by closed streamlines in the wave-relative frame, and their interior is called the wave pouch. The dynamic and thermodynamic processes of spin-up occur inside the pouch. In this study, we define the kinematic boundaries for a non-AEW disturbance in the Bay of Campeche that originated along a sharp frontal boundary in a confluent region of low pressure. We examine these boundaries during the genesis of Hurricane Nate (2011) to show how a pouch boundary on isobaric levels in the Lagrangian frame may allow for some transport into the pouch along the frontal boundary while still protecting the innermost development region. This result illustrates a generic property of weakly unsteady flows, including the time-dependent critical layer of AEWs, that lateral exchange of air occurs along a segment of the boundary formed by the instantaneous, closed translating streamlines. Transport in the Lagrangian frame is simplest when measured with respect to the stable and unstable manifolds of a hyperbolic trajectory, which are topologically invariant. In this framework, an exact analysis of vorticity transport identifies the primary source as the advection of vorticity through the entrainment and expulsion of bounded material regions called lobes. We also show how these Lagrangian boundaries impact the concentration of moisture, influence convection, and contribute to the pouch vertical structure.
Caracterización Glaciológica de Chile
Authors: Segovia Rocha Alexis Andrés , Videla Giering Yohann Alfredo 
Published: September 2017

Se realizó una caracterización glaciológica de Chile, la cual incluyó la determinación del número, superficie y el equivalente en agua contenida en los glaciares a nivel nacional (Incluidos los glaciares rocosos y campos de hielo patagónicos). La caracterización glaciológica de Chile se realizó mediante datos extraídos del Inventario Nacional de Glaciares de la Dirección General de Aguas (DGA) con actualización al año 2014, generación de información en base a procesamiento del inventario de glaciares e información bibliográfica. Dentro de los resultados, se pudo establecer que Chile posee un total estimado de 24.114 glaciares con una superficie de 23.641 km2. No obstante, esta cantidad de hielo se manifiesta con grandes diferencias regionales a lo largo del país, aumentando de norte a sur. El equivalente en agua contenida de todos los cuerpos de hielo a nivel nacional corresponde a un total
estimado de 3.175 km3.
Minimum infusion rate and adrenocortical function after continuous infusion of the novel etomidate analog ET-26-HCl in rats
Authors: Jiang Junli , Wang Bin , Zhu Zhaoqiong , Yang Jun , Liu Jin , Zhang Wensheng 
Published: September 2017

Background
Because etomidate induces prolonged adrenal suppression, even following a single bolus, its use as an infused anesthetic is limited. Our previous study indicated that a single administration of the novel etomidate analog methoxyethyletomidate hydrochloride (ET-26-HCl) shows little suppression of adrenocortical function. The aims of the present study were to (1) determine the minimum infusion rate of ET-26-HCl and compare it with those for etomidate and cyclopropyl-methoxycarbonylmetomidate (CPMM), a rapidly metabolized etomidate analog that is currently in clinical trials and (2) to evaluate adrenocortical function after a continuous infusion of ET-26-HCl as part of a broader study investigating whether this etomidate analog is suitable for long infusion in the maintenance of anesthesia.

Method
The up-and-down method was used to determine the minimum infusion rates for ET-26-HCl, etomidate and CPMM. Sprague-Dawley rats (n = 32) were then randomly divided into four groups: etomidate, ET-26-HCl, CPMM, and vehicle control. Rats in each group were infused for 60 min with one of the drugs at its predetermined minimum infusion rate. Blood samples were drawn initially and then every 30 min after drug infusion to determine the adrenocorticotropic hormone-stimulated concentration of serum corticosterone as a measure of adrenocortical function.

Results
The minimum infusion rates for etomidate, ET-26-HCl and CPMM were 0.29, 0.62, and 0.95 mg/kg/min, respectively. Compared with controls, etomidate decreased serum corticosterone, as expected, whereas serum corticosterone concentrations following infusion with the etomidate analogs ET-26-HCl or CPMM were not significantly different from those in the control group.

Conclusion
The corticosterone concentrations tended to be reduced for the first hour following ET-26-HCl infusion (as compared to vehicle infusion); however, this reduction did not reach statistical significance. Thus, further studies are warranted examining the practicability of using ET-26-HCl as an infused anesthetic.
FORMAÇÃO DO ADOLESCENTE NO ENSINO MÉDIO INTEGRADO: CONTRIBUIÇÕES DOS ESTUDOS DE VIGOTSKI
Authors: Chisté Priscila De Souza 
Published: September 2017

<p>O artigo em tela tem como objetivo compreender a importância do Ensino Médio Integrado como um modo de contribuir com a formação do adolescente. Para tanto, dialoga com autores que analisam a trajetória da Educação Profissional no Brasil, e de modo mais especifico, o Ensino Médio Integrado. Apresenta pressupostos da Psicologia Histórico-Cultural no que se refere ao adolescente e a importância da educação escolar, com o objetivo de conhecer suas peculiaridades psicológicas e entender a importância do Ensino Médio Integrado como mediador dessa formação. Utiliza como abordagem metodológica a pesquisa bibliográfica e documental tendo em vista que recorre a livros, dissertações, teses e legislações para discorrer sobre o assunto. Conclui que o Ensino Médio Integrado é um <em>lócus</em> propício para a formação integral desde que suas bases estejam sustentadas pelas ideias de formação politécnica, integral e omnilateral. <strong></strong></p>
Pore Fluid Extraction by Reactive Solitary Waves in 3‐D
Authors: Omlin Samuel , Malvoisin Benjamin , Podladchikov Yury Y. 
Published: September 2017

AbstractIn the lower crust, viscous compaction is known to produce solitary porosity and fluid pressure waves. Metamorphic (de)volatilization reactions can also induce porosity changes in response to the propagating fluid pressure anomalies. Here we present results from high‐resolution simulations using Graphic Processing Unit parallel processing with a model that includes both viscous (de)compaction and reaction‐induced porosity changes. Reactive porosity waves propagate in a manner similar to viscous porosity waves, but through a different mechanism involving fluid release and trap in the solid by reaction. These waves self‐generate from red noise or an ellipsoidal porosity anomaly with the same characteristic size and abandon their source region to propagate at constant velocity. Two waves traveling at different velocities pass through each other in a soliton‐like fashion. Reactive porosity waves thus provide an additional mechanism for fluid extraction at shallow depths with implications for ore formation, diagenesis, metamorphic veins formation, and fluid extraction from subduction zones.
Generation of Highly Oblique Lower Band Chorus Via Nonlinear Three‐Wave Resonance
Authors: Fu Xiangrong , Gary S. Peter , Reeves Geoffrey D. , Winske Dan , Woodroffe Jesse R. 
Published: September 2017

AbstractChorus in the inner magnetosphere has been observed frequently at geomagnetically active times, typically exhibiting a two‐band structure with a quasi‐parallel lower band and an upper band with a broad range of wave normal angles. But recent observations by Van Allen Probes confirm another type of lower band chorus, which has a large wave normal angle close to the resonance cone angle. It has been proposed that these waves could be generated by a low‐energy beam‐like electron component or by temperature anisotropy of keV electrons in the presence of a low‐energy plateau‐like electron component. This paper, however, presents an alternative mechanism for generation of this highly oblique lower band chorus. Through a nonlinear three‐wave resonance, a quasi‐parallel lower band chorus wave can interact with a mildly oblique upper band chorus wave, producing a highly oblique quasi‐electrostatic lower band chorus wave. This theoretical analysis is confirmed by 2‐D electromagnetic particle‐in‐cell simulations. Furthermore, as the newly generated waves propagate away from the equator, their wave normal angle can further increase and they are able to scatter low‐energy electrons to form a plateau‐like structure in the parallel velocity distribution. The three‐wave resonance mechanism may also explain the generation of quasi‐parallel upper band chorus which has also been observed in the magnetosphere.
In situ detection of boron by ChemCam on Mars
Authors: Gasda Patrick J. , Haldeman Ethan B. , Wiens Roger C. , Rapin William , Bristow Thomas F. , Bridges John C. , Schwenzer Susanne P. , Clark Benton , Herkenhoff Kenneth , Frydenvang Jens , Lanza Nina L. , Maurice Sylvestre , Clegg Samuel , Delapp Dorothea M. , Sanford Veronica L. , Bodine Madeleine R. , McInroy Rhonda 
Published: September 2017

AbstractWe report the first in situ detection of boron on Mars. Boron has been detected in Gale crater at levels <0.05 wt % B by the NASA Curiosity rover ChemCam instrument in calcium‐sulfate‐filled fractures, which formed in a late‐stage groundwater circulating mainly in phyllosilicate‐rich bedrock interpreted as lacustrine in origin. We consider two main groundwater‐driven hypotheses to explain the presence of boron in the veins: leaching of borates out of bedrock or the redistribution of borate by dissolution of borate‐bearing evaporite deposits. Our results suggest that an evaporation mechanism is most likely, implying that Gale groundwaters were mildly alkaline. On Earth, boron may be a necessary component for the origin of life; on Mars, its presence suggests that subsurface groundwater conditions could have supported prebiotic chemical reactions if organics were also present and provides additional support for the past habitability of Gale crater.