International Journal of Multiphase Flow最新文献

{"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}

{"title":"3D measurement of interfacial mass transfer of isolated millimetric bubbles in turbulence: Multi-view SI-VILF technique and simultaneous reconstruction of deforming bubble interface and surrounding concentration field","authors":"Guangyuan Huang,&nbsp;Bifan Liu,&nbsp;Yuchen Song,&nbsp;Junlian Yin,&nbsp;Dezhong Wang","doi":"10.1016/j.ijmultiphaseflow.2024.105106","DOIUrl":"10.1016/j.ijmultiphaseflow.2024.105106","url":null,"abstract":"<div><div>To deepen the understanding of the fundamentals of gas dissolution or absorption within turbulent bubbly flows, experiments of interfacial mass transfer should be performed on isolated bubbles in turbulence, while it remains pending for decades. In this paper, we propose a novel idea for indirectly determining the mass transfer coefficient <span><math><msub><mi>k</mi><mi>L</mi></msub></math></span>based on the law of conservation of mass, avoiding the challenging task of resolving the thin boundary layer at the bubble interface. Based on this idea, the multi-view SI-VLIF technique is developed for 3D measurement of the dissolution of single finite-size oxygen bubbles in turbulent environments. To handle the problem of sparse-view limited-angle imaging, improved 3D reconstruction approaches for the quantities to be measured are developed. The reconstruction qualities are evaluated utilizing synthetic and simulation datasets, and the overall uncertainty in quantifying the <span><math><msub><mi>k</mi><mi>L</mi></msub></math></span> is approximately 7%. Lastly, experiments on the oxygen dissolution of millimetric bubbles in quiescent liquid and nearly homogeneous isotropic turbulence are conducted to demonstrate the novel measuring technique. To our knowledge, this is the first time that the 3D mass transfer processes around a deforming bubble rising in turbulent environments are revealed.</div></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"184 ","pages":"Article 105106"},"PeriodicalIF":3.6,"publicationDate":"2024-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143137393","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":"Spatial evolution of droplet size and velocity characteristics in a swirl spray","authors":"S.K. Vankeswaram ,&nbsp;V. Kulkarni ,&nbsp;S. Deivandren","doi":"10.1016/j.ijmultiphaseflow.2024.105076","DOIUrl":"10.1016/j.ijmultiphaseflow.2024.105076","url":null,"abstract":"<div><div>Spray drop size distribution generated by atomization of fuel influences several facets of a combustion process such as, fuel–air mixing, reaction kinetics and thrust generation. In a typical spray, the drop size distribution evolves spatially, varying significantly between the near and far regions of the spray. However, studies so far have focused exclusively on either one of these regions and are unclear on the exact axial location where transition from near to far region droplet size characteristics is expected. In this work, we address this crucial gap by considering a swirl atomizer assembly and measuring the droplet characteristics for different liquid flow conditions of the ensuing spray at various radial and axial locations. Our results reveal an undiscovered axial variation in the scaled radial droplet velocity profiles, not followed by the radial drop size profiles, from which we unambiguously demarcate the near region as the zone which extends up to axial distances of 2.0 to 2.5 times film breakup length. Beyond this distance, the drop size characteristics are influenced by external factors such as airflow and identified as the far region of the spray. Using our analysis we locate the point of origin of the commonly reported droplet high-velocity stream along the spray centerline to the end of film breakup or near region of the spray. We also find that the global probability density functions for droplet size and velocity which show a marked difference in the near and far regions; being bimodal in the near-region and unimodal in the far-region being well represented by the double Gaussian and the Gamma distributions, respectively. We further quantify our results by meticulous measurements of number and volume flux distributions, global mean drop sizes, drop size (<span><math><msub><mrow><mi>D</mi></mrow><mrow><mi>d</mi></mrow></msub></math></span>) axial velocity (<span><math><msub><mrow><mi>U</mi></mrow><mrow><mi>a</mi></mrow></msub></math></span>) correlations, axial velocity based on drop size classification and turbulent kinetic energy (TKE) which reveal the effect of drop inertia and air flow in determining the statistics in both the near and far regions. We anticipate the findings of this work will guide future investigations on combustion processes and combustor design based on spray characteristics.</div></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"184 ","pages":"Article 105076"},"PeriodicalIF":3.6,"publicationDate":"2024-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143137394","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 polydispersity in droplet-driven flows","authors":"Sukruth Satheesh,&nbsp;Pierre Bragança,&nbsp;Christophe Cuvier,&nbsp;John-Christos Vassilicos,&nbsp;Jean-Marc Foucaut","doi":"10.1016/j.ijmultiphaseflow.2024.105080","DOIUrl":"10.1016/j.ijmultiphaseflow.2024.105080","url":null,"abstract":"<div><div>Experiments were performed on agricultural flat-fan sprays to elucidate the effect of polydisperse droplets on air induction and entrainment process using shadowgraphy and PIV. Results indicated air motion in flat-fan sprays being close to elliptical jet in terms of its growth, but velocity decay to be dependent on spray spread angle and particle size distribution. Continuous transfer of momentum from droplets of all sizes to air was observed across all measurement planes, with the velocity of smaller droplets dropping quicker to match induced air velocity values than larger ones. Most of the droplets traversed almost in a ballistic manner with only a small fraction of them interacting with air. Experiments in interacting sprays presented greater uniformity in droplet sizes, and near constant unidirectional droplet and air velocities over larger distances.</div></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"184 ","pages":"Article 105080"},"PeriodicalIF":3.6,"publicationDate":"2024-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143137399","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":"Two-dimensional particle-resolved numerical simulation for burning particles in laminar boundary layer flows","authors":"Kaiyue Wang,&nbsp;Haiou Wang,&nbsp;Kun Luo,&nbsp;Jianren Fan","doi":"10.1016/j.ijmultiphaseflow.2024.105079","DOIUrl":"10.1016/j.ijmultiphaseflow.2024.105079","url":null,"abstract":"<div><div>In the present work, two-dimensional particle-resolved simulations of burning char particles near the wall were performed to understand the effects of gap ratio, <span><math><mrow><mi>G</mi><mo>/</mo><mi>D</mi></mrow></math></span>, and particle distance, <span><math><mrow><mi>L</mi><mo>/</mo><mi>D</mi></mrow></math></span>, on the char combustion process of two burning particles, where <span><math><mi>D</mi></math></span> is the particle diameter, <span><math><mi>G</mi></math></span> is the the distance between the bottom of the particle and the wall, and <span><math><mi>L</mi></math></span> is the distance between the two particles. The results indicate that as <span><math><mrow><mi>G</mi><mo>/</mo><mi>D</mi><mspace></mspace></mrow></math></span>increases, both heterogeneous and homogeneous reaction rates of the particles increase. With <span><math><mrow><mi>L</mi><mo>/</mo><mi>D</mi><mo>=</mo><mspace></mspace><mn>1.5</mn></mrow></math></span>, the combustion of two particles can be regarded as an entity. As <span><math><mrow><mi>L</mi><mo>/</mo><mi>D</mi></mrow></math></span> increases, the reaction rate of the particles also rises. With <span><math><mrow><mi>L</mi><mo>/</mo><mi>D</mi><mspace></mspace><mo>=</mo><mspace></mspace><mn>6.0</mn></mrow></math></span>, the two particles are burning independently. The transport budgets of species on the particle surface are examined. The results show that diffusion and reaction dominate the transport of gascous species on the particle surface, while small <span><math><mrow><mi>G</mi><mo>/</mo><mi>D</mi></mrow></math></span> and<span><math><mrow><mspace></mspace><mi>L</mi><mo>/</mo><mi>D</mi></mrow></math></span> can inhibit species exchange on the surface. The drag and lift forces on combustion particles are measured. It is shown that increasing <span><math><mrow><mi>G</mi><mo>/</mo><mi>D</mi></mrow></math></span> and <span><math><mrow><mi>L</mi><mo>/</mo><mi>D</mi></mrow></math></span> results in increased the drag force of the particles, while the lift force first increases and then decreases with increasing <span><math><mrow><mi>G</mi><mo>/</mo><mi>D</mi></mrow></math></span>. Further investigation of the local drag force shows that the increase in drag force is due to the rise in the pressure component from the increased pressure drop and the rise in shear drag from both increased velo city gradient and kinematic viscosity.</div></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"184 ","pages":"Article 105079"},"PeriodicalIF":3.6,"publicationDate":"2024-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143137402","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":"Dispersions in three-phase high pressure slug flows based on X-ray measurements","authors":"G.W. Johnson ,&nbsp;T.K. Kjeldby ,&nbsp;P.S. Johansson","doi":"10.1016/j.ijmultiphaseflow.2024.105099","DOIUrl":"10.1016/j.ijmultiphaseflow.2024.105099","url":null,"abstract":"<div><div>An X-ray instrument was used to measure phase fractions for three phases over the pipe cross section in upward inclined three-phase flows at high pressure at <span><math><mrow><mn>40</mn><mspace></mspace><mi>Hz</mi></mrow></math></span>. The fluids used in the experiments were hydrocarbon gas, hydrocarbon liquid and brine at 100 bar and 70 C. A novel analytical approach was developed for analysing the X-ray time series of the local phase fractions over the pipe cross section. The experimental data included a range of water cuts and mixture velocities at 1-degree and 10-degree inclinations in a 3-inch ID pipe. Attention was given to the effects of the fraction of water on the dispersion levels in slugs flows. The X-ray had 30 vertically aligned detectors which allowed the fluid phase fractions to be quantified in each measurement region. To establish which fluid represents the continuous phase at each measurement region, certain phase inversion criteria were needed. These criteria were applied locally for each measurement detector region. The presence of any remaining phases within the region of a given continuous phase allows the quantification of the local dispersed phase fractions. Using this approach, the gas–liquid interface could be identified where the liquid layer may include significant levels of gas dispersion in the liquid. Gamma densitometers were used to corroborate the X-ray measurements for liquid holdup and to establish characteristic velocities for waves and slugs using cross correlations.</div></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"184 ","pages":"Article 105099"},"PeriodicalIF":3.6,"publicationDate":"2024-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143137396","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":"Evaluation of turbulent co-flow effects on liquid fuel atomization including spray evolution from a pressure swirl atomizer","authors":"Yaquan Sun ,&nbsp;Chetankumar S. Vegad ,&nbsp;Yongxiang Li ,&nbsp;Bruno Renou ,&nbsp;Kaushal Nishad ,&nbsp;François-Xavier Demoulin ,&nbsp;Weibing Wang ,&nbsp;Christian Hasse ,&nbsp;Amsini Sadiki","doi":"10.1016/j.ijmultiphaseflow.2024.105100","DOIUrl":"10.1016/j.ijmultiphaseflow.2024.105100","url":null,"abstract":"<div><div>Optimizing combustion systems is imperative due to current environmental and energy demands. To achieve optimal performance once liquid fuel is used for firing such systems, the liquid fuel atomization process needs to be well controlled as it determines all the subsequent multiphase flow evolution in the system. In pressure swirl atomizers, the atomization process typically relies on the combined effects of turbulent kinetic energy and non-axial kinetic energy of the fuel as it exits the nozzle. Notably, the incorporation of co-flow in the spray burner provides additional energy due to the turbulent co-flow level. In this study, numerical techniques are employed for the first time to assess the impact of varying mass flow rates of turbulent co-flow on in-nozzle flow dynamics, liquid atomization, and subsequent processes of an N-heptane spray jet from a swirl simplex atomizer. Appropriate droplet size and velocity measurements, achieved utilizing Phase Doppler Anemometry (PDA) alongside microscopic shadowgraphy to visualize spray atomization phenomena for a single co-flow mass flow rate value, are used as reference validation data. Numerically, a seamless coupling of the Volume of Fluid method (VOF) and the Lagrangian Particle Tracking (LPT) approach within a Large Eddy Simulation (LES) framework is applied. Prior to any analysis, the consistent agreement observed between simulation results and available experimental findings underscored the effectiveness of the employed approach in accurately predicting and thoroughly exploring the whole phenomena under study. Then, the impact of varying the co-flow mass rate is quantified on the in-nozzle flow-dynamics and the flow field in proximity to the gas–liquid interface. In particular, changes in the primary and secondary breakup, initial and outer spray cone angle are evaluated in terms of liquid fuel sheet thickness, breakup length and Weber number as a function of mass co-flow rates. In the dilute spray region, the effects of different co-flow turbulent conditions on the dispersion of the spray are quantitatively evidenced by means of various spray droplet statistics.</div></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"184 ","pages":"Article 105100"},"PeriodicalIF":3.6,"publicationDate":"2024-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143137398","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":"A numerical study of stretch and breakup of a ferroliquid bridge under non-uniform magnetic field","authors":"Zhi-Hui Wang ,&nbsp;Tian-Pei He ,&nbsp;Jia-Qing Li ,&nbsp;Kang-Yang Zeng ,&nbsp;Xiao-Dong Niu ,&nbsp;Adnan Khan ,&nbsp;De-Cai Li ,&nbsp;Hiroshi Yamaguchi","doi":"10.1016/j.ijmultiphaseflow.2024.105105","DOIUrl":"10.1016/j.ijmultiphaseflow.2024.105105","url":null,"abstract":"<div><div>The formation of liquid bridges between solid surfaces plays a crucial role in various applications, where precise control over their stretching and breaking is essential. Previous studies have concentrated on non-magnetic fluids. However, ferroliquids, which are magnetic fluids that become magnetized in the presence of magnetic fields, offer a unique opportunity to control liquid bridge dynamics. This study investigates the stretch and breakup dynamics of liquid bridges in ferrofluids under the influence of a non-uniform magnetic field. The simulations employ a simplified multiphase lattice Boltzmann method (SMLBM) coupled with a self-correction solution for magnetic fields to explore the effects of key parameters, including magnetic field strength, surface wettability, and ferrofluid volume, on bridge behavior. The framework of SMLBM provides computational efficiency and facilitates easy incorporation of magnetic forces for accurately modeling ferrofluid. It is shown that the magnetic field can effectively control the stretching and breakup of liquid bridges, which also depends on the boundary wettability and the liquid volume. Critical thresholds for stable bridge formation and breakup are identified, establishing the criteria for bridge stability for a specific set of parameters. This study enhances our understanding of magnetically controlled liquid bridges, laying foundation for future research and applications in advanced materials and microscale technologies.</div></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"184 ","pages":"Article 105105"},"PeriodicalIF":3.6,"publicationDate":"2024-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143137830","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 the polymer viscosity and relaxation time on the Worthington jet produced by bubble bursting in weakly viscoelastic liquids","authors":"E. Cabalgante-Corrales ,&nbsp;B.N. Muñoz-Sánchez ,&nbsp;J.M. López-Herrera ,&nbsp;M.G. Cabezas ,&nbsp;E.J. Vega ,&nbsp;J.M. Montanero","doi":"10.1016/j.ijmultiphaseflow.2024.105095","DOIUrl":"10.1016/j.ijmultiphaseflow.2024.105095","url":null,"abstract":"<div><div>We study the influence of bulk viscoelasticity on bubble bursting experimentally. We consider polymers with disparate molecular weights to analyze the effects of the polymer’s extensional relaxation time and viscosity separately. Within the parameter region explored in this study, the polymer relaxation time has a larger influence on whether a droplet is emitted or not, while the polymeric viscosity has the largest effect on the Worthington jet velocity. Viscoelasticity suppresses the droplet emission roughly if the characteristic strain rate of the Worthington jet exceeds the inverse of the polymer relaxation time. The viscosity of the polymer with the highest molecular weight is insufficient to produce noticeable effects on the Worthington jet dynamics for extensional relaxation times that lead to droplet ejection. This polymer transitions from a quasi-Newtonian behavior to droplet emission suppression as the polymer concentration increases. Polymeric viscosities <span><math><mrow><msub><mrow><mi>η</mi></mrow><mrow><mi>p</mi></mrow></msub><mo>≳</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mo>−</mo><mn>2</mn></mrow></msup></mrow></math></span> mPa s significantly affect the Worthington jet dynamics. In this case, the strain rate arising in certain phases of the bubble bursting considerably increases the jet’s extensional viscosity. As a result, the first-emitted droplet size increases, and the velocity decreases.</div></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"184 ","pages":"Article 105095"},"PeriodicalIF":3.6,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143137392","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":"Salts promote or inhibit bubbly drag reduction in turbulent Taylor–Couette flows","authors":"Luuk J. Blaauw ,&nbsp;Detlef Lohse ,&nbsp;Sander G. Huisman","doi":"10.1016/j.ijmultiphaseflow.2024.105078","DOIUrl":"10.1016/j.ijmultiphaseflow.2024.105078","url":null,"abstract":"<div><div>Bubbly drag reduction is considered as one of the most promising techniques to reduce the energy consumption of marine vessels. With this technique bubbles are injected under the hull where they then lubricate the hull, thus reducing the drag of the vessel. Understanding the effects of salts on bubbly drag reduction is therefore of crucial importance in the application of this technique for salt waters. In this study we investigate the effects of <span><math><msub><mrow><mi>MgCl</mi></mrow><mrow><mn>2</mn></mrow></msub></math></span>, <span><math><mrow><msub><mrow><mi>Na</mi></mrow><mrow><mn>2</mn></mrow></msub><msub><mrow><mi>SO</mi></mrow><mrow><mn>4</mn></mrow></msub></mrow></math></span>, substitute sea salt, and <span><math><mrow><msub><mrow><mi>NaCH</mi></mrow><mrow><mn>3</mn></mrow></msub><mi>COO</mi></mrow></math></span> on the reduction of drag by bubbles in turbulent Taylor–Couette flow. We find that <span><math><msub><mrow><mi>MgCl</mi></mrow><mrow><mn>2</mn></mrow></msub></math></span>, <span><math><mrow><msub><mrow><mi>Na</mi></mrow><mrow><mn>2</mn></mrow></msub><msub><mrow><mi>SO</mi></mrow><mrow><mn>4</mn></mrow></msub></mrow></math></span>, and substitute sea salt inhibit bubble coalescence, leading to smaller bubbles in the flow, which prove to be less effective for bubbly drag reduction. For these salts we find that the ionic strength is a decent indicator for the observed drag reduction and solutions of these salts with an ionic strength higher than <span><math><mrow><mi>I</mi><mo>≥</mo><mi>0.7 mol/L</mi></mrow></math></span> show little to no drag reduction. In contrast, <span><math><mrow><msub><mrow><mi>NaCH</mi></mrow><mrow><mn>3</mn></mrow></msub><mi>COO</mi></mrow></math></span> solutions do not inhibit bubble coalescence and for this salt we even observe an enhanced drag reduction with increasing salt concentration. Finally, for all cases we connect the observed drag reduction to the bubble Weber number and show that bubble deformability is of utmost importance for effective bubbly drag reduction.</div></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"184 ","pages":"Article 105078"},"PeriodicalIF":3.6,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143137833","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}