International Journal of Multiphase Flow最新文献_第10页

A-posteriori assessment of mixed models for Large Eddy Simulation of polydisperse multiphase flows 多分散多相流大涡模拟混合模型的后验评价

IF 3.6 2区工程技术

International Journal of Multiphase Flow Pub Date : 2025-04-12 DOI: 10.1016/j.ijmultiphaseflow.2025.105231

Andreas Iberl, Elias Trautner, Markus Klein, Josef Hasslberger

{"title":"A-posteriori assessment of mixed models for Large Eddy Simulation of polydisperse multiphase flows","authors":"Andreas Iberl, Elias Trautner, Markus Klein, Josef Hasslberger","doi":"10.1016/j.ijmultiphaseflow.2025.105231","DOIUrl":"10.1016/j.ijmultiphaseflow.2025.105231","url":null,"abstract":"<div><div>This study presents a detailed analysis of various turbulence modeling approaches for the convective subgrid-scale term in the context of Large Eddy Simulation (LES) of a polydisperse two-phase flow. The numerical framework is based on the Volume-of-Fluid (VOF) method. The presented a-posteriori investigation assesses the potential for mixed modeling combining the well-known eddy viscosity model of Smagorinsky and the scale similarity type model of Liu in two different ways. The first approach employs a dynamic blending function based on a subgrid activity sensor, whereas the second approach is based on an explicit scale separation. A preceding analysis of the laminar-turbulent transition for the Taylor-Green vortex reveals that, compared to the standalone formulation of the models, a combination of a functional and a structural model results in a more accurate prediction of the turbulent kinetic energy and its dissipation rate. The main focus of this work is on the simulation of a gas injection into a liquid-filled domain. This study presents a first investigation of advanced mixed LES models for polydisperse bubble-laden flows characterized by a realistic water-to-air density ratio. The distributions of the gas volume fraction and the gas phase velocity obtained in the LES cases employing the mixed models show a good agreement with reference data from both numerical and experimental investigations. These findings indicate that mixed type turbulence modeling is a promising candidate for an efficient and accurate prediction of industry-scale multiphase flows.</div></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"189 ","pages":"Article 105231"},"PeriodicalIF":3.6,"publicationDate":"2025-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143843189","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}

引用次数: 0

Development of the AI-assisted thermal hydraulic analysis method for condensing bubbles in vertical subcooled flow boiling 垂直过冷流沸腾冷凝气泡人工智能辅助热水力分析方法的发展

IF 3.6 2区工程技术

International Journal of Multiphase Flow Pub Date : 2025-04-12 DOI: 10.1016/j.ijmultiphaseflow.2025.105246

Wen Zhou , Shuichiro Miwa , Ryoma Tsujimura , Thanh-Binh Nguyen , Tomio Okawa , Koji Okamoto

{"title":"Development of the AI-assisted thermal hydraulic analysis method for condensing bubbles in vertical subcooled flow boiling","authors":"Wen Zhou , Shuichiro Miwa , Ryoma Tsujimura , Thanh-Binh Nguyen , Tomio Okawa , Koji Okamoto","doi":"10.1016/j.ijmultiphaseflow.2025.105246","DOIUrl":"10.1016/j.ijmultiphaseflow.2025.105246","url":null,"abstract":"<div><div>Subcooled flow boiling is critical in various industrial applications such as nuclear reactors and thermal management systems. The rapid and complex dynamics of condensing bubbles, from their inception to collapse, pose significant challenges for conventional bubble detection methods. In light of this, a state-of-the-art AI method is developed and validated for the detection and tracking of condensing bubbles in subcooled flow boiling, thereby enabling the effective execution of thermal hydraulic analyses. This study initially employs computer vision technology to efficiently construct a bubble dataset. A bubble detection model, utilizing YOLOv8 with an attention mechanism, is then trained on this dataset. Following successful bubble detection, a multi-object tracking algorithm tracks the bubbles across successive frames. The developed AI-based method has proven highly effective, detecting 95 % of condensation bubbles and streamlining the extraction of key thermal hydraulic parameters, including aspect ratio, Sauter mean diameter, void fraction, interfacial area concentration, departure diameter, growth time, bubble lifetime, Nusselt number, and nucleation site density. The model's accuracy and consistency are demonstrated compared to empirical correlations, affirming its reliability in analyzing the intricate dynamics of subcooled flow boiling. Additionally, it provides detailed fluctuation data on thermal hydraulic parameters. This AI-based method not only improves the reliability and efficiency of monitoring and analyzing subcooled flow boiling but also exemplifies the transformative potential of AI in refining complex industrial processes.</div></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"189 ","pages":"Article 105246"},"PeriodicalIF":3.6,"publicationDate":"2025-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143864673","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}

引用次数: 0

Experimental study of bubble clouds generated by multi-plunging jets 多突射流产生气泡云的实验研究

IF 3.6 2区工程技术

International Journal of Multiphase Flow Pub Date : 2025-04-12 DOI: 10.1016/j.ijmultiphaseflow.2025.105238

Narendra Dev, Hélène Scolan, J. John Soundar Jerome, Jean-Philippe Matas

{"title":"Experimental study of bubble clouds generated by multi-plunging jets","authors":"Narendra Dev, Hélène Scolan, J. John Soundar Jerome, Jean-Philippe Matas","doi":"10.1016/j.ijmultiphaseflow.2025.105238","DOIUrl":"10.1016/j.ijmultiphaseflow.2025.105238","url":null,"abstract":"<div><div>Industrial and natural processes frequently involve plunging jets that break into clusters of liquid columns or droplets, impacting the liquid surface. To simulate air entrainment by fragmented plunging jets, we first examine bubble clouds formed by twin and triple identical jets. Bubble clouds from individual jets merge after a certain pre-interaction depth and become a unified cloud, similar to the case of a single plunging jet. We then perform experiments with hexagonally packed multiple identical jets to mimic large fragmented jets. They generate a single bubble cloud without revealing a pre-interaction depth. Doppler optical probe measurements reveal that the radial profiles of air/water fraction, <span><math><mi>ϕ</mi></math></span>, are initially bimodal just after the jet impact, gradually transitioning into a single Gaussian distribution at further depth. For a given impact velocity <span><math><msub><mrow><mi>V</mi></mrow><mrow><mi>i</mi></mrow></msub></math></span>, an increase in the number of jets results in a slower decay of the mean bubble speed at the cloud axis. Furthermore, the net air flux does not scale with the number of jets but is proportional to the diameter of the multi-jet. In all cases, the mean bubble size in a bubble cloud increases with depth, which may be primarily driven by the coalescence of bubbles as suggested by high-speed images and Weber number analysis. The mean penetration depth of bubbles, <span><math><mi>H</mi></math></span>, increases with the number of jets. Our investigations indicate that the momentum flux balance in the presence of buoyancy can be successfully used to estimate bubble cloud depth and the centreline velocity in all multi-jet experiments.</div></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"189 ","pages":"Article 105238"},"PeriodicalIF":3.6,"publicationDate":"2025-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143839433","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}

引用次数: 0

Gradients-based measurements to understand the boiling characteristics of dichloromethane for thermal management applications 基于梯度的测量，以了解热管理应用中二氯甲烷的沸腾特性

IF 3.6 2区工程技术

International Journal of Multiphase Flow Pub Date : 2025-04-12 DOI: 10.1016/j.ijmultiphaseflow.2025.105258

Alok Kumar , Mohammad Autif Shahdhaar , Jaywant H. Arakeri , Atul Srivastava

{"title":"Gradients-based measurements to understand the boiling characteristics of dichloromethane for thermal management applications","authors":"Alok Kumar , Mohammad Autif Shahdhaar , Jaywant H. Arakeri , Atul Srivastava","doi":"10.1016/j.ijmultiphaseflow.2025.105258","DOIUrl":"10.1016/j.ijmultiphaseflow.2025.105258","url":null,"abstract":"<div><div>The present work investigates the dynamical characteristics of single vapor bubble during saturated nucleate boiling of dichloromethane (DCM), one of the high volatile fluids. Boiling experiments have been performed for four heat flux conditions (25, 35, 50, and 65 kW/m²) under atmospheric pressure. Thin-film interferometry and high-speed rainbow schlieren deflectometry were employed in tandem to simultaneously capture the dynamics of microlayer and/or dry-patch and vapor bubbles. A detailed analysis of the temporal evolution of the equivalent diameter of DCM bubbles reveals distinct phases: inertia-controlled growth, a transitional regime, and diffusion-controlled expansion. Furthermore, the temporal evolution of various forces, such as buoyancy, contact pressure, surface tension, and growth forces are examined during the ebullition cycle. Unlike traditional force balance analyses, the spatio-temporally resolved whole-field experimental data is used for delineating the forces involved from bubble inception to departure time (<em>t<sub>d</sub></em>). Notably, in contrast to the conventional working fluids, for instance water, DCM displays a distinct bubble formation mechanism that is devoid of any microlayer, despite its high wettability with indium-tin-oxide coated glass. As the heat flux increases, there is a corresponding linear increase in bubble departure frequency, with no significant rise in growth time. The force balance analysis during the ebullition cycle of the vapor bubble of the considered high volatile fluid reveals that until 0.8<em>t<sub>d</sub></em>, the prevailing downward force promotes bubble growth while inhibiting departure. However, beyond 0.8<em>t<sub>d</sub></em>, the upward force takes precedence, counteracting the downward force and enables the bubble's departure from the nucleating surface.</div></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"189 ","pages":"Article 105258"},"PeriodicalIF":3.6,"publicationDate":"2025-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143850599","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}

引用次数: 0

Vapor condensation heat transfer on mixed-wettability surface with lattice Boltzmann model 基于晶格玻尔兹曼模型的混合润湿性表面的蒸汽冷凝传热

IF 3.6 2区工程技术

International Journal of Multiphase Flow Pub Date : 2025-04-12 DOI: 10.1016/j.ijmultiphaseflow.2025.105259

Tong Zheng, Ruoxi Li, Xiangwei Yin, Shengqiang Shen, Gangtao Liang

{"title":"Vapor condensation heat transfer on mixed-wettability surface with lattice Boltzmann model","authors":"Tong Zheng, Ruoxi Li, Xiangwei Yin, Shengqiang Shen, Gangtao Liang","doi":"10.1016/j.ijmultiphaseflow.2025.105259","DOIUrl":"10.1016/j.ijmultiphaseflow.2025.105259","url":null,"abstract":"<div><div>Based on an improved three-dimensional phase-change lattice Boltzmann method (LBM), this study conducts three-dimensional numerical simulations for vapor condensation heat transfer on the mixed wettability surface consisting of a hydrophobic substrate decorated by the hydrophilic regions. Droplet nucleation, growth and detachment from such surface are discussed in detail, with regarding the parametric effects of the shape, size and spacing of the hydrophilic regions, as well as contact angles of both the hydrophilic and hydrophobic regions. Results show that the hydrophilic regions with identical area but different shapes lead to minor differences in heat transfer performance. However, the regions with equal perimeter but various shapes can result in significant differences. The size of the hydrophilic region is a key factor affecting droplet nucleation, and a larger hydrophilic region can increase the surface heat flux and enable earlier droplet detachment. Besides, a smaller spacing between hydrophilic regions promotes droplet formation, despite the fact that an excessively small spacing inhibits droplet detachment. The contact angles of both hydrophilic and hydrophobic regions can affect droplet formation, with the former influencing early-stage formation and the latter impacting later-stage growth. This study further improves the understanding of the mixed wettability surfaces used in the vapor condensation scenario from the numerical view.</div></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"189 ","pages":"Article 105259"},"PeriodicalIF":3.6,"publicationDate":"2025-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143843266","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}

引用次数: 0

Investigation of the fouling layer growth using coupled immersed boundary and Eulerian-Lagrangian methods 使用沉浸边界和欧拉-拉格朗日耦合方法研究污垢层的生长情况

IF 3.6 2区工程技术

International Journal of Multiphase Flow Pub Date : 2025-04-11 DOI: 10.1016/j.ijmultiphaseflow.2025.105241

Sajad Khodadadi , Reza Maddahian

{"title":"Investigation of the fouling layer growth using coupled immersed boundary and Eulerian-Lagrangian methods","authors":"Sajad Khodadadi , Reza Maddahian","doi":"10.1016/j.ijmultiphaseflow.2025.105241","DOIUrl":"10.1016/j.ijmultiphaseflow.2025.105241","url":null,"abstract":"<div><div>This study presents a numerical simulation of fouling, focusing on the complex, unsteady, multiphase, and turbulent process of fouling layer growth on the outer surface of a heat exchanger's pipe. Addressing the fundamental challenges associated with fouling phenomenon, an Eulerian-Lagrangian approach is employed, wherein the Eulerian method calculates continuous phase flow parameters, such as velocity and pressure, and the Lagrangian method precisely tracks particles near the surface. The immersed boundary method is utilized to simulate fouling layer growth without altering the underlying grid, effectively reducing computational cost compared to dynamic mesh methods. The model is validated against experimental data involving ash particle deposition on a cylindrical surface. Key parameters, including Young's modulus, Reynolds number, and particle size distribution, are systematically analyzed. The findings reveal that particles smaller than 10 micrometers can penetrate the rear of the cylinder, while larger particles (25-30 micrometers) predominantly accumulate on the front, exhibiting nearly double the deposition frequency compared to smaller particles. As particle diameter increases, both Young's modulus and flow velocity contribute to a reduced settling rate by lowering the critical deposition velocity. A higher Reynolds number results in a 67 % reduction in fouling mass due to decreased adhesive velocity and enhanced particle detachment. Additionally, larger particles tend to migrate towards the edges of the heat exchanger tube, promoting a more uniform surface distribution. Notably, at elevated Young's modulus values (e.g., 50,000 MPa), particle deposition on the surface is virtually eliminated.</div></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"189 ","pages":"Article 105241"},"PeriodicalIF":3.6,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143855968","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}

引用次数: 0

Maximum spreading-based method for determining the pre-rebounding sliding length of a water droplet after impact on an inclined superhydrophobic textured surface 确定水滴撞击倾斜超疏水纹理表面后预反弹滑动长度的基于最大扩展的方法

IF 3.6 2区工程技术

International Journal of Multiphase Flow Pub Date : 2025-04-10 DOI: 10.1016/j.ijmultiphaseflow.2025.105257

Danila Verkhodanov , Alexandra Piskunova , Maxim Piskunov , Ivan Vozhakov , Alexey Safonov , Sergey V. Starinskiy , Nikita Smirnov

{"title":"Maximum spreading-based method for determining the pre-rebounding sliding length of a water droplet after impact on an inclined superhydrophobic textured surface","authors":"Danila Verkhodanov , Alexandra Piskunova , Maxim Piskunov , Ivan Vozhakov , Alexey Safonov , Sergey V. Starinskiy , Nikita Smirnov","doi":"10.1016/j.ijmultiphaseflow.2025.105257","DOIUrl":"10.1016/j.ijmultiphaseflow.2025.105257","url":null,"abstract":"<div><div>Mathematical prediction of liquid droplet sliding along self-cleaning, anti-icing, anti-fouling and water-repellent coatings is critically attractive for research and engineering development. The work deals with the development of a semi-empirical method for estimating the sliding length of a 2.1-mm water droplet before its rebound along inclined (0-85°) superhydrophobic micro-textured surfaces with advancing contact angles of 162-164°. The method is based on energy conservation-based prediction of the maximum spreading diameter of an impacting (0.5-3.2 m/s) water droplet as a time moment preceding its sliding. In the viscous dissipation work equation, the time of maximum droplet spreading is proposed to be considered through the normal ratio of wetting and antiwetting pressures of micro-textured surfaces. The developed method revealed a linear relationship between the sliding length of a droplet and its maximum spreading diameter. It was demonstrated that modeling the wetting of the internal elements of micro-textures is a crucial step in predicting the characteristics of both processes. As a prerequisite for the creation of a semi-empirical method for estimating the sliding length, the difficulties of empirical modeling of this characteristic are reasonably presented and discussed. The validity of the method for predicting the maximum spreading coefficient is substantiated by emphasizing the importance of adhesion work in the physics of spreading. The results of the study demonstrate the effectiveness of using the micro-textured, rough surface with a selected periodicity, contact angle and free surface energy as a practical water-repellent coating. This surface structure has been demonstrated to effectively repel water in real-world applications.</div></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"189 ","pages":"Article 105257"},"PeriodicalIF":3.6,"publicationDate":"2025-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143825680","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}

引用次数: 0

One-to-one alternating droplet generation in a microfluidic double T-junction at low interfacial tension 低界面张力下微流体双t结中一对一交变液滴的产生

IF 3.6 2区工程技术

International Journal of Multiphase Flow Pub Date : 2025-04-08 DOI: 10.1016/j.ijmultiphaseflow.2025.105247

Huanhuan Jia , Yan Liu , Yuqing Zhao , Xiaoda Wang , Xiaoxi Yu

{"title":"One-to-one alternating droplet generation in a microfluidic double T-junction at low interfacial tension","authors":"Huanhuan Jia , Yan Liu , Yuqing Zhao , Xiaoda Wang , Xiaoxi Yu","doi":"10.1016/j.ijmultiphaseflow.2025.105247","DOIUrl":"10.1016/j.ijmultiphaseflow.2025.105247","url":null,"abstract":"<div><div>The one-to-one alternating droplet generation (OOAG) in a double microfluidic T-junction is a newly-developing method to construct droplet reactors. However, little attention was paid to its precise control, especially at low interfacial tension. This work filled in the gap through the experimental and theoretical exploration. Four fluid systems were adopted to make the research conclusions more general. The mechanism of flow-patten transition was analyzed to establish a predictive model describing the operation window of OOAG. Interface dynamics analysis suggested that independent of the proportion of continuous-phase, the droplet formation was suppressed and accelerated by the opposite dispersed phase at the earlier and later stages, respectively. Additionally, the opposite dispersed phase delayed the droplet breakup at low proportion of continuous phase through the interface deformation. A predictive model for droplet size was established by considering the mutual effect of the two dispersed phases and the fluid properties.</div></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"189 ","pages":"Article 105247"},"PeriodicalIF":3.6,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143820441","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}

引用次数: 0

Visualized experimental study of steam condensation on a vertical tube with non-condensable gas (air) under free convection 自由对流条件下不凝性气体（空气）在垂直管内冷凝蒸汽的可视化实验研究

IF 3.6 2区工程技术

International Journal of Multiphase Flow Pub Date : 2025-04-08 DOI: 10.1016/j.ijmultiphaseflow.2025.105248

Zengqiao Chen , Naihua Wang , Keyuan Zhang

{"title":"Visualized experimental study of steam condensation on a vertical tube with non-condensable gas (air) under free convection","authors":"Zengqiao Chen , Naihua Wang , Keyuan Zhang","doi":"10.1016/j.ijmultiphaseflow.2025.105248","DOIUrl":"10.1016/j.ijmultiphaseflow.2025.105248","url":null,"abstract":"<div><div>The presence of non-condensable gas (NCG) significantly reduces the condensation heat transfer coefficient (HTC) during steam condensation. However, the impact of condensate modes and dynamic behavior on NCG during steam condensation remains poorly understood. Moreover, prior research on the effect of wall subcooling on HTC has conflicting results. This study addresses these gaps through a visualized experimental investigation of steam condensation on the outer surface of a vertical tube under free convection with NCG (air). The experiment covered a range of parameters, including air mass fraction (0.08–0.4), wall subcooling (4–23 K), and system pressure (0.1–0.4 MPa). Visualization revealed three distinct condensate modes: film, droplet-film, and droplet-film-stream. At an air mass fraction of 0.08, a steam pressure of 0.15 MPa, and a subcooling of 10.0 K, observations on the tube wall surface revealed four dynamic features: droplet merging, droplet shedding and flushing, droplet dynamic growth, and film flow. At a steam pressure of 0.1 MPa and a subcooling of 8.0 K, a 1 % increase in air mass fraction resulted in an average decrease of 136.9 W/(m² K) in the condensation HTC below 30 % air mass fraction, and 42.9 W/(m² K) above 30 %. In particular, the HTC exhibited an increasing trend followed by a decrease with increasing wall subcooling. Based on the experimental data, an experimental correlation for the average HTC was developed as a function of air mass fraction, wall subcooling, and system pressure. The correlation accurately predicted 90 % of the experimental data within a 10 % uncertainty range.</div></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"189 ","pages":"Article 105248"},"PeriodicalIF":3.6,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143825681","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}

引用次数: 0

Experimental investigation of surfactant influence on the viscoelastic coaxial electrospray 表面活性剂对粘弹性同轴电喷雾影响的实验研究

IF 3.6 2区工程技术

International Journal of Multiphase Flow Pub Date : 2025-04-08 DOI: 10.1016/j.ijmultiphaseflow.2025.105251

Narges Ahmadi Arjanaki, Ahmad Reza Pishevar

{"title":"Experimental investigation of surfactant influence on the viscoelastic coaxial electrospray","authors":"Narges Ahmadi Arjanaki, Ahmad Reza Pishevar","doi":"10.1016/j.ijmultiphaseflow.2025.105251","DOIUrl":"10.1016/j.ijmultiphaseflow.2025.105251","url":null,"abstract":"<div><div>This study investigates the formation of a core-shell cone jet for encapsulating sunflower oil within a viscoelastic alginate solution via coaxial electrospray, with particular emphasis on the impact of surface tension by surfactant addition. Alginate, a naturally occurring linear polysaccharide, is widely used as an encapsulant due to its low cost, ease of use, and biocompatibility. High-speed imaging was employed to capture various electrohydrodynamic (EHD) modes by adjusting the applied electric potential between the coaxial nozzle and the ground electrode. The influence of operating parameters and surfactant addition on the formation of cone jet profiles was systematically analyzed. The results demonstrate that surfactant addition expanded the stable cone jet region by 132.8 % (2.33 times) on the operating maps, enabling the formation of a stable cone jet even at low Weber numbers. Surfactants enhance the miscibility between the core and shell fluids, and induce a corrugated interface, leading to an increase in the meniscus jet diameter. However, the stability of the jet at lower Weber numbers facilitated the creation of smaller particles. As the Weber number increased, the cone angle initially decreased and then increased, which is attributed to the changing viscoelastic behavior of the alginate solution under varying shear rates. Additionally, the use of surfactants reduced the cone angle of both the outer and inner fluids due to a decrease in surface tension forces.</div></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"189 ","pages":"Article 105251"},"PeriodicalIF":3.6,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143816861","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}

引用次数: 0