首页 > 最新文献

European Journal of Mechanics B-fluids最新文献

英文 中文
Euler fluid mechanics solutions to Dirac quantum mechanics equation using multipolar oscillations in spherical geometry
IF 2.5 3区 工程技术 Q2 MECHANICS Pub Date : 2024-12-27 DOI: 10.1016/j.euromechflu.2024.12.004
Álvaro Viúdez
The multipolar spherical vortex solutions to the Euler equations for Newtonian fluids in background cylindrical flow with swirl satisfy, once their three-dimensional Cartesian velocity components are mapped into the components of a four-component complex vector wave function, the relativistic Dirac equation for a free particle. It is suggested that the vertical component of the intrinsic spin angular momentum of the quantum mechanics particles is the azimuthal wavenumber of the angular phase of the oscillation modes in presence of the background rotation.
{"title":"Euler fluid mechanics solutions to Dirac quantum mechanics equation using multipolar oscillations in spherical geometry","authors":"Álvaro Viúdez","doi":"10.1016/j.euromechflu.2024.12.004","DOIUrl":"10.1016/j.euromechflu.2024.12.004","url":null,"abstract":"<div><div>The multipolar spherical vortex solutions to the Euler equations for Newtonian fluids in background cylindrical flow with swirl satisfy, once their three-dimensional Cartesian velocity components are mapped into the components of a four-component complex vector wave function, the relativistic Dirac equation for a free particle. It is suggested that the vertical component of the intrinsic spin angular momentum of the quantum mechanics particles is the azimuthal wavenumber of the angular phase of the oscillation modes in presence of the background rotation.</div></div>","PeriodicalId":11985,"journal":{"name":"European Journal of Mechanics B-fluids","volume":"111 ","pages":"Pages 81-86"},"PeriodicalIF":2.5,"publicationDate":"2024-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143102332","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Deformable droplet under Poiseuille flow: Role of flow direction, channel inclination and off-centre dynamics
IF 2.5 3区 工程技术 Q2 MECHANICS Pub Date : 2024-12-21 DOI: 10.1016/j.euromechflu.2024.12.005
Shubham Lanjewar, Sundari Ramji
The dynamics of a confined, deformable droplet with an imposed external flow (upward, quiescent and downward) is numerically investigated using an in-house solver based on the Level Set method. This is the first comprehensive investigation unravelling (i) the oscillatory dynamics of an off-centered droplet under an external flow, (ii) the hydrodynamics of a droplet subjected to a downward flow, and (iii) the effect of channel orientation. Both co-current and counter-current droplet motions are explored. While a freely falling initially off-centered droplet demonstrates an oscillatory trajectory with significant shape deformation, we show that an imposed downward flow dampens the oscillations and minimizes deformation resulting in a greater terminal speed of the droplet. Conversely, an upward, counter-current flow causes greater droplet deformation with increased oscillations. Moreover, reducing the channel inclination leads to asymmetric droplet shapes with uneven film thickness on either side of the channel and a higher residence time. The other key findings include (i) transition from convex to concave droplet tail in both upward and downward flows, dictated by the strength of external flow and Bo. (ii) Formation of a streamlined droplet accompanied by an increase in the film thickness on increasing viscosity ratio in both co-current and counter-current droplet flows and (iii) the generation of novel flow maps in the density ratio - pressure drop parameter space delineating three distinct regions: downward sinking, upward rising, and stationary droplet, depending on the relative strength of buoyancy and external flow.
{"title":"Deformable droplet under Poiseuille flow: Role of flow direction, channel inclination and off-centre dynamics","authors":"Shubham Lanjewar,&nbsp;Sundari Ramji","doi":"10.1016/j.euromechflu.2024.12.005","DOIUrl":"10.1016/j.euromechflu.2024.12.005","url":null,"abstract":"<div><div>The dynamics of a confined, deformable droplet with an imposed external flow (upward, quiescent and downward) is numerically investigated using an in-house solver based on the Level Set method. This is the first comprehensive investigation unravelling (i) the oscillatory dynamics of an off-centered droplet under an external flow, (ii) the hydrodynamics of a droplet subjected to a downward flow, and (iii) the effect of channel orientation. Both co-current and counter-current droplet motions are explored. While a freely falling initially off-centered droplet demonstrates an oscillatory trajectory with significant shape deformation, we show that an imposed downward flow dampens the oscillations and minimizes deformation resulting in a greater terminal speed of the droplet. Conversely, an upward, counter-current flow causes greater droplet deformation with increased oscillations. Moreover, reducing the channel inclination leads to asymmetric droplet shapes with uneven film thickness on either side of the channel and a higher residence time. The other key findings include (i) transition from convex to concave droplet tail in both upward and downward flows, dictated by the strength of external flow and <span><math><mi>Bo</mi></math></span>. (ii) Formation of a streamlined droplet accompanied by an increase in the film thickness on increasing viscosity ratio in both co-current and counter-current droplet flows and (iii) the generation of novel flow maps in the density ratio - pressure drop parameter space delineating three distinct regions: downward sinking, upward rising, and stationary droplet, depending on the relative strength of buoyancy and external flow.</div></div>","PeriodicalId":11985,"journal":{"name":"European Journal of Mechanics B-fluids","volume":"111 ","pages":"Pages 100-112"},"PeriodicalIF":2.5,"publicationDate":"2024-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143102375","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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
A mathematical model for viscous flow dynamics of tropical cyclones
IF 2.5 3区 工程技术 Q2 MECHANICS Pub Date : 2024-12-16 DOI: 10.1016/j.euromechflu.2024.12.003
Sanjay Kumar Pandey, Kriti Yadav
A mathematical model for tropical cyclones’ winds, taking into account various crucial considerations makes the analysis of Cecil and Majdalani (2022) more realistic. Drawing inspiration from their work which obtains the axial velocity from the stream function, we incorporate the notion of viscous flow within cyclone dynamics, a modification that brings present model more closely aligned with the real-world conditions. Our key considerations include the absence of axial velocity at the ground, zero radial velocity at the cyclone’s centre, and outside the eye-wall. In order to derive pressure, we integrate axial pressure gradient with respect to axial coordinate; and as a consequence we get an arbitrary function of radial coordinate which we eliminate by using Vatistas (1991) velocity at the ground to meet the cyclostrophic balance. Azimuthal velocity and pressure are derived for viscous flows. The formulations hold good for arbitrary Reynolds number. The analysis demonstrates a positive relationship between Reynolds number and azimuthal velocity within cyclone’s eye. This trend persists within the inner eye-wall, characterized by a gradually diminishing velocity. An inflexion point is identified midway the eye and the eye-wall, where maximum azimuthal velocities are observed. The central focus of our study revolves around the influence of eye size on various velocity components and pressure. Our findings reveal that a larger eye size correlates with the development of more intense tropical storms. However, this increase in storm intensity reaches a peak and subsequently experiences a rapid decline within the rain band region compared to smaller eye cyclones. Regardless of the eye’s size, our analysis consistently demonstrates that atmospheric pressure increases as one moves away from the eye.
{"title":"A mathematical model for viscous flow dynamics of tropical cyclones","authors":"Sanjay Kumar Pandey,&nbsp;Kriti Yadav","doi":"10.1016/j.euromechflu.2024.12.003","DOIUrl":"10.1016/j.euromechflu.2024.12.003","url":null,"abstract":"<div><div>A mathematical model for tropical cyclones’ winds, taking into account various crucial considerations makes the analysis of Cecil and Majdalani (2022) more realistic. Drawing inspiration from their work which obtains the axial velocity from the stream function, we incorporate the notion of viscous flow within cyclone dynamics, a modification that brings present model more closely aligned with the real-world conditions. Our key considerations include the absence of axial velocity at the ground, zero radial velocity at the cyclone’s centre, and outside the eye-wall. In order to derive pressure, we integrate axial pressure gradient with respect to axial coordinate; and as a consequence we get an arbitrary function of radial coordinate which we eliminate by using Vatistas (1991) velocity at the ground to meet the cyclostrophic balance. Azimuthal velocity and pressure are derived for viscous flows. The formulations hold good for arbitrary Reynolds number. The analysis demonstrates a positive relationship between Reynolds number and azimuthal velocity within cyclone’s eye. This trend persists within the inner eye-wall, characterized by a gradually diminishing velocity. An inflexion point is identified midway the eye and the eye-wall, where maximum azimuthal velocities are observed. The central focus of our study revolves around the influence of eye size on various velocity components and pressure. Our findings reveal that a larger eye size correlates with the development of more intense tropical storms. However, this increase in storm intensity reaches a peak and subsequently experiences a rapid decline within the rain band region compared to smaller eye cyclones. Regardless of the eye’s size, our analysis consistently demonstrates that atmospheric pressure increases as one moves away from the eye.</div></div>","PeriodicalId":11985,"journal":{"name":"European Journal of Mechanics B-fluids","volume":"111 ","pages":"Pages 72-80"},"PeriodicalIF":2.5,"publicationDate":"2024-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143102331","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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
Numerical investigation of the role of human motion in the spread of virus-laden droplets from coughing using CFD dynamic mesh technique
IF 2.5 3区 工程技术 Q2 MECHANICS Pub Date : 2024-12-15 DOI: 10.1016/j.euromechflu.2024.12.002
Sadegh Sadeghi, Saiied M. Aminossadati, Christopher Leonardi
The transmission of viruses through the air plays a crucial role in the spread of viral diseases in enclosed environments. The mobility of individuals is a potential factor that contributes to the increment of the propagation of respiratory infections through the air. This research comprehensively focuses on transient modelling of the spread of solid-containing droplets during a cough from a moving person inside a ventilated room through CFD approach. This study investigates a range of moving speeds, from 0 to 1.5 m/s, to illustrate differences in patterns and concentration of droplets during both mobile and stationary conditions of an individual considering the interactions among gas, liquid and solid phases. Interactions between phases are considered through a coupled Eulerian–Lagrangian approach, and discrete phase model (DPM), turbulence model, species transport model, evaporation model and dynamic mesh technique are integrated. Moreover, the influences of effective forces such as buoyancy, Brownian motion, drag, lift, and gravitational forces are included. Regarding the results, motion of individuals significantly affects the airflow pattern and dispersion of droplets, particularly for walking speeds of more than 1 m/s. The results also elaborately indicate that person’s movement (from 0 to 1.5 m/s) considerably enhances the turbulent intensity (about 40 %), average air velocity and oscillations in pressure distribution, especially, pressure gradient before and after the moving person (about 1.5 Pa). Additionally, when the person walks at speeds exceeding 1 m/s, most of the particles cannot attach to the person’s body due to insufficient time for settling, resulting in an increment in the total number of particles that remain suspended in the air.
{"title":"Numerical investigation of the role of human motion in the spread of virus-laden droplets from coughing using CFD dynamic mesh technique","authors":"Sadegh Sadeghi,&nbsp;Saiied M. Aminossadati,&nbsp;Christopher Leonardi","doi":"10.1016/j.euromechflu.2024.12.002","DOIUrl":"10.1016/j.euromechflu.2024.12.002","url":null,"abstract":"<div><div>The transmission of viruses through the air plays a crucial role in the spread of viral diseases in enclosed environments. The mobility of individuals is a potential factor that contributes to the increment of the propagation of respiratory infections through the air. This research comprehensively focuses on transient modelling of the spread of solid-containing droplets during a cough from a moving person inside a ventilated room through CFD approach. This study investigates a range of moving speeds, from 0 to 1.5 m/s, to illustrate differences in patterns and concentration of droplets during both mobile and stationary conditions of an individual considering the interactions among gas, liquid and solid phases. Interactions between phases are considered through a coupled Eulerian–Lagrangian approach, and discrete phase model (DPM), turbulence model, species transport model, evaporation model and dynamic mesh technique are integrated. Moreover, the influences of effective forces such as buoyancy, Brownian motion, drag, lift, and gravitational forces are included. Regarding the results, motion of individuals significantly affects the airflow pattern and dispersion of droplets, particularly for walking speeds of more than 1 m/s. The results also elaborately indicate that person’s movement (from 0 to 1.5 m/s) considerably enhances the turbulent intensity (about 40 %), average air velocity and oscillations in pressure distribution, especially, pressure gradient before and after the moving person (about 1.5 Pa). Additionally, when the person walks at speeds exceeding 1 m/s, most of the particles cannot attach to the person’s body due to insufficient time for settling, resulting in an increment in the total number of particles that remain suspended in the air.</div></div>","PeriodicalId":11985,"journal":{"name":"European Journal of Mechanics B-fluids","volume":"111 ","pages":"Pages 42-60"},"PeriodicalIF":2.5,"publicationDate":"2024-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143102329","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
A discrete Immersed Boundary Method for the numerical simulation of heat transfer in compressible flows
IF 2.5 3区 工程技术 Q2 MECHANICS Pub Date : 2024-12-12 DOI: 10.1016/j.euromechflu.2024.12.001
H. Riahi , P. Errante , E. Goncalves da Silva , M. Meldi
In the present study, a discrete forcing Immersed Boundary Method (IBM) is proposed for the numerical simulation of high-speed flow problems including heat exchange. This class of tools is relevant for several applications in engineering studies for aerospace applications, notably for atmospheric reentry. The flow field is governed by the compressible Navier–Stokes equations, which are resolved by using the open source library OpenFOAM. The numerical solver is modified to include source terms in the momentum equation and in the energy equation, which account for the presence of the immersed body. The method is validated on some benchmark test cases dealing with forced convection problems and moving immersed bodies. The results obtained are in very good agreement with data provided in the literature. The method is further assessed by investigating three-dimensional high Mach flows around a heated sphere with different wall temperature. Even for this more complex test case, the method provides an accurate representation of both thermal and velocity fields.
{"title":"A discrete Immersed Boundary Method for the numerical simulation of heat transfer in compressible flows","authors":"H. Riahi ,&nbsp;P. Errante ,&nbsp;E. Goncalves da Silva ,&nbsp;M. Meldi","doi":"10.1016/j.euromechflu.2024.12.001","DOIUrl":"10.1016/j.euromechflu.2024.12.001","url":null,"abstract":"<div><div>In the present study, a discrete forcing Immersed Boundary Method (IBM) is proposed for the numerical simulation of high-speed flow problems including heat exchange. This class of tools is relevant for several applications in engineering studies for aerospace applications, notably for atmospheric reentry. The flow field is governed by the compressible Navier–Stokes equations, which are resolved by using the open source library OpenFOAM. The numerical solver is modified to include source terms in the momentum equation and in the energy equation, which account for the presence of the immersed body. The method is validated on some benchmark test cases dealing with forced convection problems and moving immersed bodies. The results obtained are in very good agreement with data provided in the literature. The method is further assessed by investigating three-dimensional high Mach flows around a heated sphere with different wall temperature. Even for this more complex test case, the method provides an accurate representation of both thermal and velocity fields.</div></div>","PeriodicalId":11985,"journal":{"name":"European Journal of Mechanics B-fluids","volume":"111 ","pages":"Pages 61-71"},"PeriodicalIF":2.5,"publicationDate":"2024-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143102330","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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
Filler advert: scival_2021_210x280.pdf
IF 2.5 3区 工程技术 Q2 MECHANICS Pub Date : 2024-12-10 DOI: 10.1016/S0997-7546(24)00179-1
{"title":"Filler advert: scival_2021_210x280.pdf","authors":"","doi":"10.1016/S0997-7546(24)00179-1","DOIUrl":"10.1016/S0997-7546(24)00179-1","url":null,"abstract":"","PeriodicalId":11985,"journal":{"name":"European Journal of Mechanics B-fluids","volume":"110 ","pages":"Page I"},"PeriodicalIF":2.5,"publicationDate":"2024-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143149422","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 turbulent high-speed flow over the double wedge at varying aft-wedge deflections
IF 2.5 3区 工程技术 Q2 MECHANICS Pub Date : 2024-12-04 DOI: 10.1016/j.euromechflu.2024.11.012
Anurag Adityanarayan Ray , Ashoke De
This study examines the shock–shock (SSI) and shock-wave boundary layer (SBLI) interaction mechanisms over the two-dimensional double wedge exposed to hypersonic Mach 5 flow. Several Unsteady Reynolds-averaged Navier Stokes (URANS) based turbulence models are used systematically to determine the most suitable model. Grid sensitivity analysis indicates that while the laminar model is sensitive to grid size, turbulent models exhibit grid independence, suggesting the laminar model’s unsuitability under these conditions. We further support this hypothesis by a qualitative and quantitative comparison of the numerical schlieren images and mean wall heat flux profiles, respectively, with the experimental results. The average heat flux based on the fully laminar assumption provides accurate predictions in the well-attached flow region, but it fails horribly after the SBLI interaction. The models using the standard kω SST (shear stress transport) turbulence model and the four-equation Lantry–Menter correlation-based model consistently overpredict the wall heat transfer rate throughout the double-wedge surface. The newly employed Krause correlations significantly improve the match with the qualitative and quantitative experimental observations. This article further uses this novel turbulence model to explore the impact of the aft-wedge angle variation (450θ2600) on the shock–shock interaction mechanisms and the associated wall properties. Results indicate a weak Edney type-V interaction at the lowest angle, transitioning to Edney type-V with Mach reflection for θ2500. Hence, the critical transition aft-wedge angle concerning the change in the shock interference pattern is between θ2=450 and θ2=500.
{"title":"Investigation of turbulent high-speed flow over the double wedge at varying aft-wedge deflections","authors":"Anurag Adityanarayan Ray ,&nbsp;Ashoke De","doi":"10.1016/j.euromechflu.2024.11.012","DOIUrl":"10.1016/j.euromechflu.2024.11.012","url":null,"abstract":"<div><div>This study examines the shock–shock (SSI) and shock-wave boundary layer (SBLI) interaction mechanisms over the two-dimensional double wedge exposed to hypersonic Mach 5 flow. Several Unsteady Reynolds-averaged Navier Stokes (URANS) based turbulence models are used systematically to determine the most suitable model. Grid sensitivity analysis indicates that while the laminar model is sensitive to grid size, turbulent models exhibit grid independence, suggesting the laminar model’s unsuitability under these conditions. We further support this hypothesis by a qualitative and quantitative comparison of the numerical schlieren images and mean wall heat flux profiles, respectively, with the experimental results. The average heat flux based on the fully laminar assumption provides accurate predictions in the well-attached flow region, but it fails horribly after the SBLI interaction. The models using the standard <span><math><mrow><mi>k</mi><mo>−</mo><mi>ω</mi></mrow></math></span> SST (shear stress transport) turbulence model and the four-equation Lantry–Menter correlation-based model consistently overpredict the wall heat transfer rate throughout the double-wedge surface. The newly employed Krause correlations significantly improve the match with the qualitative and quantitative experimental observations. This article further uses this novel turbulence model to explore the impact of the aft-wedge angle variation (<span><math><mrow><mn>4</mn><msup><mrow><mn>5</mn></mrow><mrow><mn>0</mn></mrow></msup><mo>≤</mo><msub><mrow><mi>θ</mi></mrow><mrow><mn>2</mn></mrow></msub><mo>≤</mo><mn>6</mn><msup><mrow><mn>0</mn></mrow><mrow><mn>0</mn></mrow></msup></mrow></math></span>) on the shock–shock interaction mechanisms and the associated wall properties. Results indicate a weak Edney type-V interaction at the lowest angle, transitioning to Edney type-V with Mach reflection for <span><math><mrow><msub><mrow><mi>θ</mi></mrow><mrow><mn>2</mn></mrow></msub><mo>≥</mo><mn>5</mn><msup><mrow><mn>0</mn></mrow><mrow><mn>0</mn></mrow></msup></mrow></math></span>. Hence, the critical transition aft-wedge angle concerning the change in the shock interference pattern is between <span><math><mrow><msub><mrow><mi>θ</mi></mrow><mrow><mn>2</mn></mrow></msub><mo>=</mo><mn>4</mn><msup><mrow><mn>5</mn></mrow><mrow><mn>0</mn></mrow></msup></mrow></math></span> and <span><math><mrow><msub><mrow><mi>θ</mi></mrow><mrow><mn>2</mn></mrow></msub><mo>=</mo><mn>5</mn><msup><mrow><mn>0</mn></mrow><mrow><mn>0</mn></mrow></msup></mrow></math></span>.</div></div>","PeriodicalId":11985,"journal":{"name":"European Journal of Mechanics B-fluids","volume":"111 ","pages":"Pages 20-41"},"PeriodicalIF":2.5,"publicationDate":"2024-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143093202","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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
Flow topology of the wake of a rotor and its relationship with the energy efficiency
IF 2.5 3区 工程技术 Q2 MECHANICS Pub Date : 2024-12-02 DOI: 10.1016/j.euromechflu.2024.11.010
A.C. Espinosa Ramírez, Oscar Velasco Fuentes
A numerical model is used to study the flow in the wake of a two-bladed horizontal-axis rotor. The flow topology is analyzed for three different angular velocities of the rotor. For the fastest rotor there is a region downstream where the fluid loses nearly 30% of the axial inflow velocity, whereas almost 60% is lost if this region belongs to the wake of a second-in-line rotor. The second part of this study deals with the evolution of the tip helical vortices in the presence of a turbulent inflow wind. This is found to destabilize the vortices, which subsequently perform a leapfrogging motion. As the turbulence of the inflow wind strengthens, the leapfrogging starts closer to the wind rotor. If a second-in-line rotor is located in this wake, the power it extracts from the wind depends on its location with respect to the point where the first rotor’s vortices become unstable. A second rotor located downstream of this point extracts more power than one located upstream of this point.
{"title":"Flow topology of the wake of a rotor and its relationship with the energy efficiency","authors":"A.C. Espinosa Ramírez,&nbsp;Oscar Velasco Fuentes","doi":"10.1016/j.euromechflu.2024.11.010","DOIUrl":"10.1016/j.euromechflu.2024.11.010","url":null,"abstract":"<div><div>A numerical model is used to study the flow in the wake of a two-bladed horizontal-axis rotor. The flow topology is analyzed for three different angular velocities of the rotor. For the fastest rotor there is a region downstream where the fluid loses nearly 30% of the axial inflow velocity, whereas almost 60% is lost if this region belongs to the wake of a second-in-line rotor. The second part of this study deals with the evolution of the tip helical vortices in the presence of a turbulent inflow wind. This is found to destabilize the vortices, which subsequently perform a leapfrogging motion. As the turbulence of the inflow wind strengthens, the leapfrogging starts closer to the wind rotor. If a second-in-line rotor is located in this wake, the power it extracts from the wind depends on its location with respect to the point where the first rotor’s vortices become unstable. A second rotor located downstream of this point extracts more power than one located upstream of this point.</div></div>","PeriodicalId":11985,"journal":{"name":"European Journal of Mechanics B-fluids","volume":"111 ","pages":"Pages 1-10"},"PeriodicalIF":2.5,"publicationDate":"2024-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143102376","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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
Free-surface flow due to a line source near a vertical barrier
IF 2.5 3区 工程技术 Q2 MECHANICS Pub Date : 2024-12-02 DOI: 10.1016/j.euromechflu.2024.11.011
W.F. Mansoor , G.C. Hocking
The unsteady flow generated by a line source that is located at an arbitrary location beneath the free surface of a fluid of finite depth is considered when there is vertical barrier located nearby. The surface may have surface tension. The barrier is shown to have a significant effect on the wave height generated at the barrier and the outward travelling bore generated by the initiation of the flow. Simulations of free surface flows are very difficult due to the formation of curvature singularities on the surface. The method employed in this work does not appear to have these difficulties and the solutions can be computed almost up until the moment the wave breaks, including in some cases a significant spill at the front. A linearized solution and a fully nonlinear solution are presented and the results compared and discussed.
{"title":"Free-surface flow due to a line source near a vertical barrier","authors":"W.F. Mansoor ,&nbsp;G.C. Hocking","doi":"10.1016/j.euromechflu.2024.11.011","DOIUrl":"10.1016/j.euromechflu.2024.11.011","url":null,"abstract":"<div><div>The unsteady flow generated by a line source that is located at an arbitrary location beneath the free surface of a fluid of finite depth is considered when there is vertical barrier located nearby. The surface may have surface tension. The barrier is shown to have a significant effect on the wave height generated at the barrier and the outward travelling bore generated by the initiation of the flow. Simulations of free surface flows are very difficult due to the formation of curvature singularities on the surface. The method employed in this work does not appear to have these difficulties and the solutions can be computed almost up until the moment the wave breaks, including in some cases a significant spill at the front. A linearized solution and a fully nonlinear solution are presented and the results compared and discussed.</div></div>","PeriodicalId":11985,"journal":{"name":"European Journal of Mechanics B-fluids","volume":"111 ","pages":"Pages 11-19"},"PeriodicalIF":2.5,"publicationDate":"2024-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143093201","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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
Suppression of rankine vortex formation in liquid draining tanks: A critical review 排液槽中兰肯涡形成的抑制:综述
IF 2.5 3区 工程技术 Q2 MECHANICS Pub Date : 2024-11-23 DOI: 10.1016/j.euromechflu.2024.11.009
Mahadev Prabhu, C.M. Hariprasad, R. Ajith Kumar
Air-core vortexing phenomenon during draining of liquids from cylindrical vessels is of major interest because this phenomenon has significant impact in multiple engineering systems. The adverse effects created by vortex formation via air-core ingestion in the field of aerospace engineering, metal casting and hydraulic engineering demanded the need for air-core vortex suppression. From past few decades, researchers have come up with unique strategies to suppress vortexing phenomenon. As the first ever initiative, the current review classifies all the strategies reported in the literature and addresses the advantages and adverse effects of each strategy. Based on this classification, this review identifies vortex suppression strategies suitable for various engineering applications. The present review also investigates the contradictions and misinterpretations observed in the published results. Research gaps and major outcomes identified in this review are novel and are expected to give a fresh impetus for further research delivering new insights on the phenomenon of air core vortex formation aiding to develop new suppression strategies.
在圆柱形容器排液过程中,空气芯涡现象引起了人们的广泛关注,因为这种现象对多种工程系统都有重要的影响。在航空航天工程、金属铸造和水利工程等领域,通过吸入空气芯形成涡流所产生的不利影响要求对空气芯涡流进行抑制。在过去的几十年里,研究人员提出了独特的策略来抑制涡旋现象。作为有史以来的第一个倡议,目前的审查分类所有的战略报道在文献和解决每个战略的优势和不利影响。在此基础上,本文综述了适用于各种工程应用的涡抑制策略。本综述还调查了在已发表的结果中观察到的矛盾和误解。本综述中发现的研究空白和主要成果是新颖的,有望为进一步的研究提供新的动力,提供对空气核心涡形成现象的新见解,有助于开发新的抑制策略。
{"title":"Suppression of rankine vortex formation in liquid draining tanks: A critical review","authors":"Mahadev Prabhu,&nbsp;C.M. Hariprasad,&nbsp;R. Ajith Kumar","doi":"10.1016/j.euromechflu.2024.11.009","DOIUrl":"10.1016/j.euromechflu.2024.11.009","url":null,"abstract":"<div><div>Air-core vortexing phenomenon during draining of liquids from cylindrical vessels is of major interest because this phenomenon has significant impact in multiple engineering systems. The adverse effects created by vortex formation via air-core ingestion in the field of aerospace engineering, metal casting and hydraulic engineering demanded the need for air-core vortex suppression. From past few decades, researchers have come up with unique strategies to suppress vortexing phenomenon. As the first ever initiative, the current review classifies all the strategies reported in the literature and addresses the advantages and adverse effects of each strategy. Based on this classification, this review identifies vortex suppression strategies suitable for various engineering applications. The present review also investigates the contradictions and misinterpretations observed in the published results. Research gaps and major outcomes identified in this review are novel and are expected to give a fresh impetus for further research delivering new insights on the phenomenon of air core vortex formation aiding to develop new suppression strategies.</div></div>","PeriodicalId":11985,"journal":{"name":"European Journal of Mechanics B-fluids","volume":"110 ","pages":"Pages 34-64"},"PeriodicalIF":2.5,"publicationDate":"2024-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142745524","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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
期刊
European Journal of Mechanics B-fluids
全部 Acc. Chem. Res. ACS Applied Bio Materials ACS Appl. Electron. Mater. ACS Appl. Energy Mater. ACS Appl. Mater. Interfaces ACS Appl. Nano Mater. ACS Appl. Polym. Mater. ACS BIOMATER-SCI ENG ACS Catal. ACS Cent. Sci. ACS Chem. Biol. ACS Chemical Health & Safety ACS Chem. Neurosci. ACS Comb. Sci. ACS Earth Space Chem. ACS Energy Lett. ACS Infect. Dis. ACS Macro Lett. ACS Mater. Lett. ACS Med. Chem. Lett. ACS Nano ACS Omega ACS Photonics ACS Sens. ACS Sustainable Chem. Eng. ACS Synth. Biol. Anal. Chem. BIOCHEMISTRY-US Bioconjugate Chem. BIOMACROMOLECULES Chem. Res. Toxicol. Chem. Rev. Chem. Mater. CRYST GROWTH DES ENERG FUEL Environ. Sci. Technol. Environ. Sci. Technol. Lett. Eur. J. Inorg. Chem. IND ENG CHEM RES Inorg. Chem. J. Agric. Food. Chem. J. Chem. Eng. Data J. Chem. Educ. J. Chem. Inf. Model. J. Chem. Theory Comput. J. Med. Chem. J. Nat. Prod. J PROTEOME RES J. Am. Chem. Soc. LANGMUIR MACROMOLECULES Mol. Pharmaceutics Nano Lett. Org. Lett. ORG PROCESS RES DEV ORGANOMETALLICS J. Org. Chem. J. Phys. Chem. J. Phys. Chem. A J. Phys. Chem. B J. Phys. Chem. C J. Phys. Chem. Lett. Analyst Anal. Methods Biomater. Sci. Catal. Sci. Technol. Chem. Commun. Chem. Soc. Rev. CHEM EDUC RES PRACT CRYSTENGCOMM Dalton Trans. Energy Environ. Sci. ENVIRON SCI-NANO ENVIRON SCI-PROC IMP ENVIRON SCI-WAT RES Faraday Discuss. Food Funct. Green Chem. Inorg. Chem. Front. Integr. Biol. J. Anal. At. Spectrom. J. Mater. Chem. A J. Mater. Chem. B J. Mater. Chem. C Lab Chip Mater. Chem. Front. Mater. Horiz. MEDCHEMCOMM Metallomics Mol. Biosyst. Mol. Syst. Des. Eng. Nanoscale Nanoscale Horiz. Nat. Prod. Rep. New J. Chem. Org. Biomol. Chem. Org. Chem. Front. PHOTOCH PHOTOBIO SCI PCCP Polym. Chem.
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
0
微信
客服QQ
Book学术公众号 扫码关注我们
反馈
×
意见反馈
请填写您的意见或建议
请填写您的手机或邮箱
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
现在去查看 取消
×
提示
确定
Book学术官方微信
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术
文献互助 智能选刊 最新文献 互助须知 联系我们:info@booksci.cn
Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。
Copyright © 2023 Book学术 All rights reserved.
ghs 京公网安备 11010802042870号 京ICP备2023020795号-1