International Journal of Multiphase Flow最新文献

{"title":"A unified spray model for large eddy simulations under non-flashing and flash boiling conditions: Effects of in-nozzle flow and external thermal breakup in liquid ammonia injection","authors":"Zhuoying Jin ,&nbsp;Haoqing Wu ,&nbsp;Shijie Xu ,&nbsp;Dezhi Zhou ,&nbsp;Shijie Mi ,&nbsp;Yong Qian ,&nbsp;Xingcai Lu","doi":"10.1016/j.ijmultiphaseflow.2024.105116","DOIUrl":"10.1016/j.ijmultiphaseflow.2024.105116","url":null,"abstract":"<div><div>As a carbon-free fuel, liquid ammonia is promising to be applied in gas turbines and marine engines to facilitate the decarbonization of energy and transportation sectors. However, ammonia has a high saturation pressure which leads to the transition from non-flashing to flash boiling atomization mechanisms and introduces challenges in modeling the liquid ammonia spray. It is essential to study the spray behavior and propose a unified spray model with high accuracy and implementation efficiency under wide operation conditions. In this study, a numerical model is developed under the Lagrangian-Eulerian framework to consider various breakup mechanisms. This model is then adopted for the spray simulations of liquid ammonia and validated against measurements. Firstly, the spray patterns are classified as normal evaporation (Rp ≥ 1.0), external flash boiling (1.0 &lt; Rp ≤ 0.3), transitional and fully flash boiling (Rp &lt; 0.3) through atomization mechanism analysis. Aiming at various spray patterns, a numerical model is developed involving the in-nozzle flow effect, external thermal breakup, and secondary aerodynamic breakup. The model comparison and validation results under different conditions show the proper prediction ability of the present model with accurate spray penetration and morphology. Compared with the typical aerodynamic breakup model, the spray expansion through the radial velocity increment of child droplets is well reproduced in the present model by considering the external thermal breakup. In addition, the improved boundary conditions that account for the in-nozzle flow effects enable a better prediction under the transitional and fully flash boiling region. Then the spray characteristics analysis of liquid ammonia under various conditions is conducted. It is found that the flash boiling plays an important role in primary atomization and generates smaller droplets. The initial spray expansion due to in-nozzle flow, later low air resistance, and continuous acceleration of small droplets leads to relatively slow and then fast penetration of flash boiling spray. Furthermore, a more complete spray mixing and evaporation process in both axial and radial directions is observed under the Rp0.1 condition. Nevertheless, the cooling effects resulted from the high latent heat of ammonia and subsequent wetting problem for combustion chamber wall should also be considered in practical applications. This study fills the gaps between measurements and predictions of the liquid ammonia spray under the transition from non-flashing to flash boiling conditions.</div></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"184 ","pages":"Article 105116"},"PeriodicalIF":3.6,"publicationDate":"2024-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143138003","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Drop impact onto a moving substrate: Aerodynamic rebound","authors":"Bastian Stumpf ,&nbsp;Samaneh Abdi Qezeljeh ,&nbsp;Reda Kamal ,&nbsp;Fabien Dezitter ,&nbsp;Alessandro Martuffo ,&nbsp;Ilia V. Roisman ,&nbsp;Jeanette Hussong","doi":"10.1016/j.ijmultiphaseflow.2024.105113","DOIUrl":"10.1016/j.ijmultiphaseflow.2024.105113","url":null,"abstract":"<div><div>The dynamics of droplets approaching fast moving surfaces of high surface-tangential velocities is relevant to numerous technical applications, such as icing phenomena in aviation. Due to the substrate motion a boundary layer is formed which interacts with impacting droplets. In the present study, the transition from drop impact and splashing to boundary layer induced drop rebound is investigated for varying drop diameters, drop and plate velocity, as well as impact angles. It is found that this transition is strongly influenced by the degree of drop deformation that is induced by aerodynamic forces acting on the drop when it enters the boundary layer. Based on these considerations, a threshold model is obtained that describes the transition from splash to aerodynamic rebound. It is shown that the model is valid for a laminar and a turbulent boundary layer agreeing well with own and existing experimental data.</div></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"184 ","pages":"Article 105113"},"PeriodicalIF":3.6,"publicationDate":"2024-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143137942","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Correlations for aerodynamic force coefficients of non-spherical particles in compressible flows","authors":"Christian Gorges ,&nbsp;Victor Chéron ,&nbsp;Anjali Chopra ,&nbsp;Fabian Denner ,&nbsp;Berend van Wachem","doi":"10.1016/j.ijmultiphaseflow.2024.105111","DOIUrl":"10.1016/j.ijmultiphaseflow.2024.105111","url":null,"abstract":"<div><div>This study presents particle-resolved direct numerical simulations using three-dimensional body-fitted hexahedral meshes to investigate the aerodynamic force and torque coefficients of non-spherical particles in compressible flows. The simulations focus on three particle shapes: a prolate spheroid, an oblate spheroid, and a rod-like particle, across a range of Mach numbers (0.3 to 2.0), angles of attack (0°to 90°), and particle Reynolds numbers (100 to 300). Results show that the particle shape significantly impacts the aerodynamic forces on a particle in a compressible flow, with oblate spheroids exhibiting the highest drag, lift, and torque values. Correlations for these aerodynamic coefficients of the particles in a compressible flow are developed and validated. These correlations advance multiphase flow modelling by improving the accuracy of point-particle simulations for non-spherical particles in compressible flows.</div></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"184 ","pages":"Article 105111"},"PeriodicalIF":3.6,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143138004","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Oscillatory two-phase flow dynamics in capillary tubes under microgravity conditions: Numerical modeling and qualitative analysis of the flow structures","authors":"Tomasz Duraziński ,&nbsp;Andrzej Ireneusz Nowak ,&nbsp;Jun Ishimoto ,&nbsp;Sławomir Pietrowicz","doi":"10.1016/j.ijmultiphaseflow.2024.105107","DOIUrl":"10.1016/j.ijmultiphaseflow.2024.105107","url":null,"abstract":"<div><div>This work examines the oscillatory motion of gas–liquid structures in <span><math><mi>P</mi></math></span>ulsating <span><math><mi>H</mi></math></span>eat <span><math><mi>P</mi></math></span>ipes (PHP), which is critical for designing passive cooling systems for microgravity applications. Accurately capturing gas–liquid volume fraction behavior is crucial for understanding the mechanisms driving the break-up and coalescence of the gas plugs. Experimental data obtained from the ZARM drop tower facility in Bremen, Germany, were used to validate numerical simulations conducted with OpenFOAM v2106, employing the <span><math><mi>V</mi></math></span>olume <span><math><mi>O</mi></math></span>f <span><math><mi>F</mi></math></span>luid (VOF) method. In experiments, ethanol was utilized as the working under two distinct initial vapor bubble configurations. A boundary condition enforcing the oscillatory behavior of the velocity vector was implemented in the simulations. The results demonstrate high of accuracy in reproducing the observed flow structures, providing a qualitative comparison between the algebraic VOF method and experimental observations. The simulations successfully captured the oscillatory dynamics of two-phase structures, offering valuable insights into vapor bubble behavior in microgravity. While heat transfer was not included in the present analysis, these findings are a foundation for future studies integrating thermal-flow processes. This preliminary analysis advances the understanding of PHP behavior in microgravity and highlights pathways for more comprehensive modeling efforts.</div></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"184 ","pages":"Article 105107"},"PeriodicalIF":3.6,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143137937","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Scale effects of the tip-leakage flow with and without cavitation: A numerical study in OpenFOAM","authors":"Xiaotao Zhao ,&nbsp;Huaiyu Cheng ,&nbsp;Bin Ji ,&nbsp;Rickard E. Bensow","doi":"10.1016/j.ijmultiphaseflow.2024.105108","DOIUrl":"10.1016/j.ijmultiphaseflow.2024.105108","url":null,"abstract":"<div><div>Large eddy simulations of the tip-leakage vortex (TLV) flow around the NACA0009 hydrofoil are performed in OpenFOAM to study the scale effects of the tip-leakage vortex profile with and without cavitation. An incompressible single-phase solver and an in-house advanced compressible cavitating flow solver are employed to reproduce the evolution of the TLV and tip-leakage vortex cavitation (TLVC), respectively. By changing the incoming velocity and the hydrofoil size, six cases are divided into three different flow conditions: velocity scale, size scale and Reynolds number similarity. Comparing the predicted results with the experimental data from literature, a satisfying agreement is obtained. Some crucial flow characteristics, e.g. vortex structures, vortex intensity, vortex trajectory and wandering, velocity distribution, fluctuation features, and TLVC evolution, are studied in detail and the scale effects of them are significant. With the increasing incoming velocity or scale ratio, more pronounced vortex fusion occurs and makes the TLV maintain a higher intensity downstream. The greater the incoming velocity or scale ratio, the more the TLV is pulled away from the hydrofoil and the weaker the amplitude of TLV wandering. Moreover, the transition of axial flow profile from jet-like to wake-like is delayed by increasing the incoming velocity/scale ratio. An increase in incoming velocity or scale ratio leads to an increase in circulation and a decrease in the radius of TLV core, facilitating the occurrence of TLVC. With equal Reynolds number and cavitation number, the scale effects of tip-leakage flows can be neglected.</div></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"184 ","pages":"Article 105108"},"PeriodicalIF":3.6,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143138007","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Role of the process conditions on three-dimensional viscous fingering: Impact on enhanced oil recovery and geological storage","authors":"Pooja Singh,&nbsp;Sourav Mondal","doi":"10.1016/j.ijmultiphaseflow.2024.105110","DOIUrl":"10.1016/j.ijmultiphaseflow.2024.105110","url":null,"abstract":"<div><div>The problem of viscous fingering is a scientific challenge in oil recovery and geological storage. The phenomena of viscous fingering in a three dimensional setting is widely different from the 2D analogue. Here, we study the three-dimensional viscous fingering morphology to investigate the effect of fluid miscibility and porous medium permeability. High resolution industrial grade X-ray micro-computer-tomography scanning is used to explore the 3D instability patterns. The phase miscibility of the injection fluid to the displaced fluid affects the fingering phenomena, transitioning from dispersion limited to diffusion. The areal sweep efficiency is higher for miscible case and is invariant with flow rates. We have used the fractal analysis to analyse the complex patterns, and the fractal dimension is related to the process conditions. We report 3D diffusion-limited aggregation simulations to obtain patterns similar to the miscible fingering patterns and provide insights on the pattern growth behaviour.</div></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"184 ","pages":"Article 105110"},"PeriodicalIF":3.6,"publicationDate":"2024-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143138008","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Transition to entrainment in downward annular gas-liquid flow: Study through flow control","authors":"Andrey Cherdantsev,&nbsp;Sergey Isaenkov,&nbsp;Dmitry Markovich","doi":"10.1016/j.ijmultiphaseflow.2024.105109","DOIUrl":"10.1016/j.ijmultiphaseflow.2024.105109","url":null,"abstract":"<div><div>Formation of disturbance waves and entrainment of liquid droplets drastically enhances pressure drop and heat and mass transfer in annular flow. Here we investigate the transition to entrainment by analyzing spatiotemporal records of film thickness in the vicinity of the transition border. Two branches of the border: “vertical”, with high gas speeds and low liquid flow rates, and “horizontal”, with low gas speeds and large liquid flow rates, are analyzed separately. In both cases, low-frequency pulsations of liquid flow rate are applied in attempt to expand the regime area of entrainment and learn more about the transition. It was found that two conditions are necessary for creation of a disturbance wave: strong localized perturbations able to create the initial hump of liquid and enough spare liquid in excess of the viscous sub-layer to fill and maintain this hump. Below the “vertical” branch, the disturbance waves do not occur due to lack of spare liquid. Below the “horizontal” branch, no sources of strong perturbations are present. Both “vertical” and “horizontal” branches can be shifted towards lower values of liquid flow rate and gas speed, respectively, using low-frequency oscillations of liquid flow rate. However, the mechanisms of creating these artificial disturbance waves are different. For “vertical” branch, the pulsations create patches of larger liquid flow rate, where disturbance waves can be created in a “natural” manner. For “horizontal” branch, each pulsation period creates a single disturbance wave, provided that the excitation frequency belongs to appropriate range.</div></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"184 ","pages":"Article 105109"},"PeriodicalIF":3.6,"publicationDate":"2024-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143137397","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prediction of bubbly flow and flow regime development in a horizontal air-water pipe flow with a morphology-adaptive multifluid CFD model","authors":"Marco Colombo ,&nbsp;Michael Fairweather","doi":"10.1016/j.ijmultiphaseflow.2024.105112","DOIUrl":"10.1016/j.ijmultiphaseflow.2024.105112","url":null,"abstract":"<div><div>Most multiphase gas-liquid flows of industrial and engineering interest often encompass multiple flow regimes and the transition between them. The wide range of interface scales involved is challenging to model, and this has so far limited the application of computational fluid dynamics to multi-regime flows and complex multiphase flow conditions. The morphology-adaptive GEneralized Multifluid Modelling Approach (GEMMA), developed in OpenFOAM, is designed to provide all-flow-regime modelling capabilities. The model implements in the multifluid modelling framework interface-resolving capabilities that are used to treat large-scale interfaces found in segregated flow regimes, while dispersed regimes remain modelled with the standard multifluid approach. In this paper, GEMMA is used to predict, for the horizontal pipe flow studied in the METERO experiment (Bottin et al., 2014), the development of the bubbly, plug, slug and stratified flow regimes starting from a homogeneous 1 mm bubble distribution at the inlet of the pipe. In the bubbly regime, the model predicts well the void fraction and bubble diameter distributions, but not the lower flow velocity when a bubble layer accumulates at the top of the pipe. Results also show that modelling closures developed mainly for vertical flow conditions, and which are a strong function of the relative velocity, may not be equipped to predict horizontal flows where relative velocities can be negligible. Beyond the bubbly regime, the model predicts the development of intermittent gas plugs, the increase in the length scale of the plugs approaching the transition to slug flow and the development of a stratified flow at the lowest water flow rate. The velocity of gas plugs is found to be in good agreement with literature models. Challenging to predict remains the transition region from bubbly to plug and from slug to stratified flow, where an anticipated transition to stratified flow is predicted in the slug regime. Overall, GEMMA provides a morphology-adaptive modelling framework that can achieve all-flow regime applicability, and the present work is a first demonstration of its capabilities for horizontal flow regimes. Short-term development needs are highlighted, such as additional validation and the improvement of bubbly flow closures, and the modelling of the dispersion and breaking-up of large interfaces to prevent excessive phase agglomeration.</div></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"184 ","pages":"Article 105112"},"PeriodicalIF":3.6,"publicationDate":"2024-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143138006","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of two-phase turbulent modalities and bubble-induced turbulence on polydispersed bubbly flow in continuous casting mold","authors":"Yu Li ,&nbsp;Zhongqiu Liu ,&nbsp;Yuchao Yao ,&nbsp;Baokuan Li ,&nbsp;Guodong Xu","doi":"10.1016/j.ijmultiphaseflow.2024.105104","DOIUrl":"10.1016/j.ijmultiphaseflow.2024.105104","url":null,"abstract":"<div><div>A crucial challenge for gas-liquid two-phase flow is modeling two-phase turbulent modalities and bubble-induced turbulence (BIT). Although many shear-induced turbulence (SIT) models have been established and widely used in single-phase flow, there is no consensus on extending single-phase flow to gas-liquid flow. This work presents the development of the novel population balance model (PBM) for simulating multiphase flows in continuous casting (CC) mold. The effect of two-phase turbulent modalities, SIT and BIT mechanisms on flow pattern, bubble distribution and bubble diameter were studied and against with the experimental data. The results show that the RNG model shows better agreement than other models for predicting flow patterns and bubble size. Compared with the experimental values, the mean relative error of Sauter mean diameter is 5.74 %. Furthermore, the correlation between three turbulent modalities and the SIT has been revealed. The turbulence properties predicted by dispersed-modality and per-modality are highly consistent, and the mixture-modality extremely overestimates the bubble size. The dispersed-modality is suitable for simulating gas-liquid flow for CC mold. Finally, we reveal the coupling mechanism between BIT and SIT models. The Simonin model is insufficient to describe the BIT effect due to the low momentum exchange. The Sato model only caused slight perturbation for the Standard model and significantly increased the turbulence viscosity predicted by RNG model. The coupling between the RNG and Sato models can achieve a circulation feedback effect.</div></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"184 ","pages":"Article 105104"},"PeriodicalIF":3.6,"publicationDate":"2024-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143137390","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Freely falling cylinders of length to diameter ratio around one","authors":"G. Bouchet ,&nbsp;J. Dušek","doi":"10.1016/j.ijmultiphaseflow.2024.105097","DOIUrl":"10.1016/j.ijmultiphaseflow.2024.105097","url":null,"abstract":"<div><div>The paper presents numerical simulations of the free fall of homogeneous cylinders of length to diameter ratios 0.8 through 1.6 and solid to fluid density ratios <span><math><mrow><msub><mrow><mi>ρ</mi></mrow><mrow><mi>s</mi></mrow></msub><mo>/</mo><mi>ρ</mi></mrow></math></span> going from 0 to 5 in transitional regimes. The results shed light on the transition from flat cylinders falling with their axis oriented vertically or oscillating about this equilibrium position to oblong cylinders keeping a horizontal or predominantly horizontal orientation. A significant bi-stability region extending as much as to an interval of <span><math><mrow><mi>L</mi><mo>/</mo><mi>d</mi></mrow></math></span> ratios of <span><math><mrow><mn>0</mn><mo>.</mo><mn>9</mn><mo>≤</mo><mi>L</mi><mo>/</mo><mi>d</mi><mo>≤</mo><mn>1</mn><mo>.</mo><mn>35</mn></mrow></math></span> shortly before the onset of path instabilities has been evidenced. With the onset of path instabilities, the scenario starts to depend on the density ratio and the bi-stability domain progressively disappears. In these regimes, cylinders of length to diameter ratio 0.9 and 1 are observed to change periodically or intermittently the orientation of their axis. Cylinders of ratio <span><math><mrow><mi>L</mi><mo>/</mo><mi>d</mi><mo>=</mo><mn>1</mn><mo>.</mo><mn>6</mn></mrow></math></span> behave qualitatively like those of ratio <span><math><mrow><mi>L</mi><mo>/</mo><mi>d</mi><mo>≥</mo><mn>2</mn></mrow></math></span> investigated elsewhere and present subcritical effects for density ratio of 5.</div></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"184 ","pages":"Article 105097"},"PeriodicalIF":3.6,"publicationDate":"2024-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143137400","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}