International Journal of Multiphase Flow最新文献

{"title":"Pore-scale investigation on porous media morphology evolution considering dissolution and precipitation","authors":"H. Hao ,&nbsp;Z.G. Xu","doi":"10.1016/j.ijmultiphaseflow.2023.104569","DOIUrl":"10.1016/j.ijmultiphaseflow.2023.104569","url":null,"abstract":"<div><p>Mineral dissolution and precipitation are commonly encountered in geologic CO₂ injection. In this study, a novel method DLA-QSGS coupling diffusion limited aggregation (DLA) and quartet structure generation set (QSGS) is proposed to generate random distribution of mineral components and fluid. As an example of application, the reactive transport process is then numerically studied with various pore morphology using the lattice Boltzmann method at pore-scale. An insoluble mineral component and soluble mineral components that involve simple and complex reactions for dissolution and precipitation are considered. The impact of mirror morphology, channel width and sub-channels on solid volume evolution and hydrogen ion concentration are investigated. The temperature field is affected by the channel width and sub-channel number. The results suggest that the technique increasing channel numbers is more effective than that increasing channel width during CO₂ fracturing.</p></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"168 ","pages":"Article 104569"},"PeriodicalIF":3.8,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41492408","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":"Combined optical connectivity and optical flow velocimetry measurement of interfacial velocity of a liquid jet in gas crossflow","authors":"Tianyi Wang,&nbsp;Yannis Hardalupas","doi":"10.1016/j.ijmultiphaseflow.2023.104581","DOIUrl":"10.1016/j.ijmultiphaseflow.2023.104581","url":null,"abstract":"<div><p>Liquid jet in crossflow (LJIC) is a process in which a high-speed gas crossflow deforms and shears a continuous liquid flow into tiny droplets. This study quantifies the liquid surface motion of LJIC during the primary breakup process, which has not been quantified due to the optical limitation close to the nozzle exit. The interfacial velocity of a breaking liquid jet indicates the local interaction of the gas and liquid flows and determines the initial velocity of the stripped droplets. The local interfacial liquid velocities of LJIC have only been estimated from theoretical and computational studies, which have not been evaluated from measurements. Optical Connectivity (OC) introduces a laser beam through an atomiser nozzle and relies on total internal reflection at the liquid interface to propagate the laser light inside the continuous liquid to record the instantaneous features of the interface of the continuous liquid during the primary atomisation at the near nozzle region through imaging of the emitted fluorescent intensity from the liquid flow. The current study combines Optical Connectivity with Optical Flow Velocimetry (OFV) to quantify the time-dependent, local interfacial velocity of the liquid interface structures of the LJIC for gas Weber numbers between 14.9 - 112.6 and liquid-to-gas momentum ratios between 2.1 - 36.4. The combined OC-OFV measurements of the spatial distribution of the mean and fluctuating values of the different components of the liquid interfacial velocity of LJIC demonstrate how the gaseous shear and liquid jet geometry interact to influence the atomisation process.</p></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"168 ","pages":"Article 104581"},"PeriodicalIF":3.8,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S030193222300201X/pdfft?md5=7bb0ccba4adc3017afb8acc846217e60&pid=1-s2.0-S030193222300201X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41813875","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":"A three-dimensional non-orthogonal multiple-relaxation-time phase-field lattice Boltzmann model for multiphase flows at large density ratios and high Reynolds numbers","authors":"Geng Wang ,&nbsp;Junyu Yang ,&nbsp;Timan Lei ,&nbsp;Jin Chen ,&nbsp;Qian Wang ,&nbsp;Kai H. Luo","doi":"10.1016/j.ijmultiphaseflow.2023.104582","DOIUrl":"10.1016/j.ijmultiphaseflow.2023.104582","url":null,"abstract":"<div><p>This study proposes a three-dimensional non-orthogonal multiple-relaxation-time (NMRT) phase-field multiphase lattice Boltzmann (PFLB) model within a recently established unified lattice Boltzmann model (ULBM) framework [Luo et al., Phil. Trans. R. Soc. A 379, 20200397, 2021]. The conservative Allen-Cahn equation and the incompressible Navier-Stokes (NS) equations are solved. In addition, a local gradient calculation scheme for the order parameter of the Allen-Cahn equation is constructed with the non-equilibrium part of the distribution function. A series of benchmark cases are conducted to validate the proposed model, including the two-phase Poiseuille flow, Rayleigh-Taylor instability, binary liquid/metal droplet collision, and a bubble rise in water. The present simulation results are in good agreement with existing simulation and experimental data. In the simulation of the co-current two-phase Poiseuille flow, the present model is proven to resolve the discontinuity at the phase interface and provide accurate results at extremely high density ratios (i.e., up to <span><math><msup><mrow><mn>10</mn></mrow><mn>6</mn></msup></math></span>). Finally, the proposed model is adopted to simulate two challenging cases: (1) water droplet splashing during its impacting on a thin liquid film and (2) liquid jet breakup. The simulation results demonstrate an excellent agreement with previous experimental results, both qualitatively and quantitatively. In these simulations, the Weber number and Reynolds number reach 10⁵ and 6000, respectively, and the viscosity can be as low as <span><math><mrow><mo>∼</mo><msup><mrow><mn>10</mn></mrow><mrow><mo>−</mo><mn>4</mn></mrow></msup></mrow></math></span>, in the lattice unit.</p></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"168 ","pages":"Article 104582"},"PeriodicalIF":3.8,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0301932223002021/pdfft?md5=7bbeada99167d443c149484694de5cad&pid=1-s2.0-S0301932223002021-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41845316","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":"Simulation of multiphase flow in pipes with simplified models of deposited beds","authors":"Min Liu (刘敏) ,&nbsp;Lee F. Mortimer ,&nbsp;Bisrat Wolde ,&nbsp;Michael Fairweather ,&nbsp;Yanlin Zhao (赵彦琳) ,&nbsp;Jun Yao (姚军)","doi":"10.1016/j.ijmultiphaseflow.2023.104625","DOIUrl":"10.1016/j.ijmultiphaseflow.2023.104625","url":null,"abstract":"<div><p>Turbulent particle-laden flows in pipes can result in particle deposition leading to the formation of solid beds. The presence of such beds modifies the flow field, resulting in secondary motions in the plane of the pipe cross-section, which in turn impact particle transport. In this work turbulent pipe flows with equal mass flow rates and solid beds of height <em>H</em>_b = 0 (full pipe), 0.5<em>R</em> (three-quarter pipe), and <em>R</em> (half pipe) are predicted using direct numerical simulation, with the beds represented simplistically as flat surfaces. The particulate phase is one-way coupled to the flow at a volume fraction of 10⁻³ and particle motion is solved for using a Lagrangian point-particle approach. The Reynolds numbers computed based on bulk velocity and equivalent pipe diameter for the full, ¾ and, ½ pipes are 5,300, 5,909 and 7,494, respectively. The same particle size is used in all the simulations and their respective Stokes numbers, based on the shear timescale, are 0.5, 1.2 and 1.9, respectively. The results for flows with beds show that the fluid flow exhibits secondary vortices and an increase in the mean streamwise vorticity caused by corners in the cross-sectional plane of the pipes, with their intensity near the upper curved wall increasing with <em>H</em>_b. However, the upper vortices remain relative weak compared to those in lower regions of the pipes. The increase in mean streamwise vorticity in the half pipe is larger than that in the three-quarter pipe near the upper curved wall, while similar near the flat pipe floor due to the resistance of the curved wall to secondary motions. The movement of the particles in the cross-sectional plane is consistent with that of the secondary flows, but with slightly lower velocities. In regions near the wall away from the pipe corners, particle concentration in the half pipe is lower than in the three-quarter pipe, most likely due to its thinner boundary layer. This is reversed for concentration maxima near the pipe corners because of the magnitude of the secondary flows. Finally, the secondary flow changes the deposition or resuspension rate of the particles, particularly near the pipe corners, but these are always less than equivalent rates in the full pipe flow, which is likely caused by the magnitude of the wall unit.</p></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"170 ","pages":"Article 104625"},"PeriodicalIF":3.8,"publicationDate":"2023-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41088442","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":"Effects of gas flow rate on rising bubble chains and induced flow fields: An experimental study","authors":"Han-bin Wang ,&nbsp;Yang Xu ,&nbsp;Si-ying Li ,&nbsp;Jin-jun Wang","doi":"10.1016/j.ijmultiphaseflow.2023.104623","DOIUrl":"10.1016/j.ijmultiphaseflow.2023.104623","url":null,"abstract":"<div><p>This paper reports an experimental investigation of the characteristics of bubble chains and their induced flow fields in a quiescent fluid at gas flow rates of 5, 10, 50, and 100 ml/min. The shadowgraphy and laser-induced-fluorescence particle image velocimetry (LIF-PIV) were used to analyze quantitatively the bubble morphology, kinematics, and induced flow fields. The results show that with increasing gas flow rate, the bubbles exhibit a larger average diameter, aspect ratio, and more-abundant morphology. The bubble motion includes a rectilinear rise followed by an oscillating rise, and the position where the bubble deviates from the linear trajectory is associated with the point of maximum bubble aspect ratio. The amplitude of bubble oscillation and the position of the instability both increase with the gas flow rate, except for the case of 50 ml/min. The bubble-induced flow field at higher gas flow rates exhibits stronger entrainment, which reflects the ability of the flow to entrain the surrounding fluid. The instantaneous flow-field results show that bubble-induced wake shedding is the main cause of the change in bubble rise state and trajectory instability. The direction of bubble deflection is related directly to the sequence of wake shedding: when the clockwise (resp. counterclockwise) vortex in the wake is the first to shed, the bubble deflects to the left (resp. right). The study also reveals that the simultaneous shedding of counterclockwise and clockwise vortices at 50 ml/min results in the bubbles continuing to rise rectilinearly for a period of time, and the position of trajectory destabilization has a maximum height.</p></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"170 ","pages":"Article 104623"},"PeriodicalIF":3.8,"publicationDate":"2023-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41088444","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":"Mixing and solvent exchange near the turbulent/non-turbulent interface in a quasi-2D jet","authors":"You-An Lee ,&nbsp;Sander G. Huisman ,&nbsp;Detlef Lohse","doi":"10.1016/j.ijmultiphaseflow.2023.104608","DOIUrl":"10.1016/j.ijmultiphaseflow.2023.104608","url":null,"abstract":"<div><p>We inject with jet mixtures of ethanol and dissolved anise oil upward into quiescent water with jet Reynolds numbers, <span><math><mrow><mn>500</mn><mo>&lt;</mo><mi>R</mi><msub><mrow><mi>e</mi></mrow><mrow><mn>0</mn></mrow></msub><mo>&lt;</mo><mn>810</mn></mrow></math></span>. Nucleation of oil droplets, also known as the ouzo effect, follows from the entrainment and mixing with the ambient water, in which the oil has much lower oil solubility than the initial jet fluid. We experimentally investigate the local concentration during solvent exchange near the turbulent/non-turbulent interface (TNTI) in the quasi-two-dimensional turbulent jet. Using a light attenuation technique, we measure the concentration fields for the solvent exchange case (the nucleated oil droplets) and the reference dye case (passive scalar).</p><p>Combining conventional and conditional mean profiles, we show that the nucleation of oil droplets is initiated near the TNTI upstream, and penetrates into the turbulent region as the jet travels downstream. Persistent nucleation not only sustains the scalar dissipation rate, but also leads to enhanced temporal fluctuations of the concentrations till the downstream (high) position. The probability density functions (PDFs) of the concentration exhibit pronounced bimodal shapes near the TNTI and positively-skewed curves toward the centerline, which also suggest that the oil droplets nucleate across the jet upon mixing.</p><p>In addition to the qualitative investigation, we also describe the process more quantitatively. Based on the idea that the concentration field of the nucleated oil micro-droplets is linked to the ethanol concentration field running in the background, we estimate the nucleation rate near the TNTI using a control volume approach. We model the concentration field of the nucleated oil using that of the passive scalar and the ternary phase diagram of a water, ethanol, and anise oil mixture.</p><p>This study extends our previous work on the mean field, revealing more details of the turbulent statistics induced by solvent exchange. The findings shed new light on the interplay between mixing and nucleation in a quasi-2D turbulent jet. We also provide the first modeling of solvent exchange in turbulent flows with a simple model based on ethanol concentration field and the phase diagram.</p></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"169 ","pages":"Article 104608"},"PeriodicalIF":3.8,"publicationDate":"2023-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0301932223002288/pdfft?md5=22b191335912696675f168d918613ce9&pid=1-s2.0-S0301932223002288-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42216677","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":"Numerical simulation of angled-injected liquid jet breakup in supersonic crossflow by a hybrid VOF-LPT method","authors":"Wenyuan Zhou ,&nbsp;Bing Chen ,&nbsp;Qingbo Zhu ,&nbsp;Sihang Rao ,&nbsp;Xu Xu","doi":"10.1016/j.ijmultiphaseflow.2023.104503","DOIUrl":"https://doi.org/10.1016/j.ijmultiphaseflow.2023.104503","url":null,"abstract":"<div><p>The breakup of angled-injected liquid jets in supersonic airflow is investigated numerically by a hybrid Volume of Fluid and Lagrangian Particle Tracking (VOF-LPT) method. A Multi-criterion adaptive mesh refinement (AMR) procedure and dynamic load balancing (DLB) algorithm are applied to improve the accuracy of interface and shock wave characteristics and reduce the use of computational resources and liquid mass loss. The flow characteristics of the spray field and penetration depth of the angled-injected liquid jet from the simulations agreed well with the experimental results. Under the supersonic crossflow conditions, the jet has momentum in the counter-flow direction that improves gas-liquid interactions. The penetration depth of the liquid jet increase with the increase of the injection angle. In particular, the penetration depth of the angled-injected liquid jet is given in the: <span><math><mrow><mi>y</mi><mo>/</mo><mi>d</mi><mo>=</mo><mn>0.12</mn><mo>·</mo><mi>sin</mi><mrow><mo>(</mo><mrow><mn>2</mn><mi>θ</mi><mo>/</mo><mn>3</mn></mrow><mo>)</mo></mrow><mo>·</mo><msup><mrow><mo>(</mo><msup><mrow><mi>e</mi></mrow><mrow><mi>sin</mi><mo>(</mo><mrow><mn>2</mn><mi>θ</mi><mo>/</mo><mn>3</mn></mrow><mo>)</mo></mrow></msup><mo>)</mo></mrow><mrow><mn>3.185</mn></mrow></msup><mo>·</mo><msup><mrow><mi>q</mi></mrow><mrow><mn>0.389</mn></mrow></msup><msup><mrow><mo>(</mo><mrow><mi>x</mi><mo>/</mo><mi>d</mi></mrow><mo>)</mo></mrow><mrow><mn>0.309</mn></mrow></msup></mrow></math></span>. Moreover, the liquid jet at a larger injection angle has a larger spray spread angle and wider wake region due to the larger windward area. Furthermore, the total pressure loss of airflow increases with the injection angle increasing. Considering the total pressure loss for all injection conditions is lower than 14%, the total pressure loss caused by the injection angle increase can be negligible.</p></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"166 ","pages":"Article 104503"},"PeriodicalIF":3.8,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"1890073","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":"Effect of interpolation kernels and grid refinement on two way-coupled point-particle simulations","authors":"Nathan A. Keane ,&nbsp;Sourabh V. Apte ,&nbsp;Suhas S. Jain ,&nbsp;Makrand A. Khanwale","doi":"10.1016/j.ijmultiphaseflow.2023.104517","DOIUrl":"https://doi.org/10.1016/j.ijmultiphaseflow.2023.104517","url":null,"abstract":"<div><p><span>The predictive capability of two way-coupled point-particle Euler–Lagrange model in accurately capturing particle–flow interactions under grid refinement, wherein the particle size can be comparable to the grid size, is systematically evaluated. Two situations are considered, (i) uniform flow over a stationary particle, and (ii) decaying </span>isotropic turbulence laden with Kolmogorov-scale particles. Particle–fluid interactions are modeled using only the standard drag law, typical of large density-ratio systems. A zonal, advection–diffusion–reaction (Zonal-ADR) model is used to obtain the undisturbed fluid velocity needed in the drag closure. Two main types of interpolation kernels, grid-based and particle size-based, are employed. The effect of interpolation kernels on capturing the particle–fluid interactions, kinetic energy, dissipation rate, and particle acceleration statistics are evaluated in detail. It is shown that the interpolation kernels whose width scales with the particle size perform significantly better under grid refinement than kernels whose width scales with the grid size. Convergence with respect to spatial resolution is obtained with the particle size-based kernels with and without correcting for the self-disturbance effect. While the use of particle size-based interpolation kernels provide spatial convergence and perform better than kernels that scale based on grid size, small differences can still be seen in the converged results with and without correcting for the particle self-disturbance. Such differences indicate the need for self-disturbance correction to obtain the best results, especially when the particles are larger than the grid size.</p></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"166 ","pages":"Article 104517"},"PeriodicalIF":3.8,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"3140455","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":"Acoustic state detection of microbubble emission boiling using a deep neural network based on cepstrum analysis","authors":"Junichiro Ono ,&nbsp;Yuta Aoki ,&nbsp;Noriyuki Unno ,&nbsp;Kazuhisa Yuki ,&nbsp;Koichi Suzuki ,&nbsp;Yoshitaka Ueki ,&nbsp;Shin-ichi Satake","doi":"10.1016/j.ijmultiphaseflow.2023.104512","DOIUrl":"https://doi.org/10.1016/j.ijmultiphaseflow.2023.104512","url":null,"abstract":"<div><p>Microbubble emission boiling (MEB) is a cooling technology in which the heat flux can potentially exceed the critical heat flux (CHF). Reliable predictions of the occurrence of MEB are necessary to achieve stable MEB and to induce it under actual environment conditions. In this study, we developed a method based on deep learning with boiling sound to predict the boiling state of the interval before the low-heat-flux level reaches MEB. The boiling sound was acquired by a hydrophone, and the sound was adopted to machine learning algorithms, which were subsequently applied to classification and regression models. The feature extraction algorithms for the boiling sounds were spectrum or cepstrum methods. Both methods were comparatively investigated in terms of the machine learning accuracy. As a result, in the case of the cepstrum method as the feature extraction, the accuracy was improved. In particular, we found that the regression model demonstrated substantially better accuracy than the classification model. In addition, accurate predictions were possible even when the degree of subcooling was changed.</p></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"166 ","pages":"Article 104512"},"PeriodicalIF":3.8,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"1517259","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":"The effects of Stefan flow on the flow surrounding two closely spaced particles","authors":"Thamali R. Jayawickrama ,&nbsp;M.A. Chishty ,&nbsp;Nils Erland L. Haugen ,&nbsp;Matthaus U. Babler ,&nbsp;Kentaro Umeki","doi":"10.1016/j.ijmultiphaseflow.2023.104499","DOIUrl":"https://doi.org/10.1016/j.ijmultiphaseflow.2023.104499","url":null,"abstract":"<div><p>The aim of the work was to study the effects of neighboring particles with uniform Stefan flow in particle–fluid flows. Particle-resolved numerical simulations were carried out for particles emitting a uniform Stefan flow into the bulk fluid. The bulk fluid was uniform and isothermal. The Stefan flow volume emitted from the two particles is equal, such that it represents idealized conditions of reacting particles. Particles were located in tandem arrangement and particle distances were varied between 1.1 and 10 particle diameters (<span><math><mrow><mn>1</mn><mo>.</mo><mn>1</mn><mo>≤</mo><mi>L</mi><mo>/</mo><mi>D</mi><mo>≤</mo><mn>10</mn></mrow></math></span>). Three particle Reynolds numbers were considered during the simulations (<span><math><mrow><mi>R</mi><mi>e</mi><mo>=</mo><mn>2</mn><mo>.</mo><mn>3</mn><mo>,</mo><mn>7</mn></mrow></math></span> and 14), which is similar to our previous studies. Three Stefan flow velocities were also considered during simulations to represent inward, outward, and no Stefan flow. The drag coefficient of the particles without Stefan flow showed that the results fit with previous studies on neighbor particle effects. When the particle distance is greater than 2.5 diameters (<span><math><mrow><mi>L</mi><mo>/</mo><mi>D</mi><mo>&gt;</mo><mn>2</mn><mo>.</mo><mn>5</mn></mrow></math></span>), the effects of Stefan flow and neighboring particles are independent of each other. I.e. an outward Stefan flow decreases the drag coefficient (<span><math><msub><mrow><mi>C</mi></mrow><mrow><mi>D</mi></mrow></msub></math></span>) while an inward Stefan flow increases it and the <em>upstream</em> particle experience a higher <span><math><msub><mrow><mi>C</mi></mrow><mrow><mi>D</mi></mrow></msub></math></span> than the <em>downstream</em> particle. When <span><math><mrow><mi>L</mi><mo>/</mo><mi>D</mi><mo>≤</mo><mn>2</mn><mo>.</mo><mn>5</mn></mrow></math></span>, the effect of Stefan flow is dominant, such that equal and opposite pressure forces act on the particles, resulting in a repelling force between the two neighboring particles. The pressure force showed a large increase compared to the viscous force at these distances. The effect of Stefan flow is weakened at higher Reynolds numbers. A model was developed for the calculation of the drag coefficient. The model, which reproduce the results from the numerical simulations presented above, is a product of independent models that describe the effects of both neighboring particles and two distinguished effects of the Stefan flow.</p></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"166 ","pages":"Article 104499"},"PeriodicalIF":3.8,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"1890075","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}