Flow, Turbulence and Combustion最新文献

{"title":"Advances in Turbulence, Heat and Mass Transfer","authors":"Kemal Hanjalić, Domenico Borello, Kazuhiko Suga, Paolo Venturini","doi":"10.1007/s10494-025-00644-9","DOIUrl":"10.1007/s10494-025-00644-9","url":null,"abstract":"","PeriodicalId":559,"journal":{"name":"Flow, Turbulence and Combustion","volume":"114 Heat and Mass Transfer","pages":"711 - 712"},"PeriodicalIF":2.0,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143612123","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}

{"title":"Numerical Simulation of the Agglomeration Behaviour of Spheroidal Particle Pairs in Chaotic Flows","authors":"Jacob P. Anderson,&nbsp;Lee F. Mortimer,&nbsp;Timothy N. Hunter,&nbsp;Jeffrey Peakall,&nbsp;Michael Fairweather","doi":"10.1007/s10494-025-00635-w","DOIUrl":"10.1007/s10494-025-00635-w","url":null,"abstract":"<div><p>Interactions between attractive spheroidal particles are studied in boxes of chaotic flow under the action of a homogeneous and isotropic forcing technique. The fully resolved fluid field and structure-resolved particle–fluid coupling regime are obtained through direct numerical simulation and an immersed boundary method. Agglomeration outcomes are accommodated through attractive van der Waals forces, suitably adapted to consider the orientational dependencies associated with the non-spherical shape. Binary particle interactions are first studied in quiescent conditions, as well as in a periodic box of chaotic fluid flow. The latter is forced using a stochastic method, where the magnitude of the velocity fluctuations and Taylor–Reynolds number are chosen based on those typically seen in nuclear waste processing scenarios. Differences in particle interaction behaviours are presented for the cases of disks and needles, with the role of orientation and kinetic energy in determining interaction outcomes analysed and contrasted with spheres. Results indicate that needles have the highest agglomeration propensity in the chaotic fluid, followed by spheres, and then disks. Lastly, the inclusion of attractive orientationally-dependent interaction forces promotes alignment between the symmetry axes of spheroidal particle pairs, whilst the increased action of the fluid was also seen to promote alignment between the interacting particles when compared to the quiescent case.</p></div>","PeriodicalId":559,"journal":{"name":"Flow, Turbulence and Combustion","volume":"114 Heat and Mass Transfer","pages":"941 - 965"},"PeriodicalIF":2.0,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10494-025-00635-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143612301","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}

{"title":"On the Impact of CFD Turbulence Models for Premixed ({text{NH}}_{3})/({text{H}}_{2}) Combustion on Emissions and Flame Characteristics in a Swirl-Stabilized Burner","authors":"Luca Mazzotta,&nbsp;Rachele Lamioni,&nbsp;Giuliano Agati,&nbsp;Adriano Evangelisti,&nbsp;Franco Rispoli,&nbsp;Agustin Valera-Medina,&nbsp;Domenico Borello","doi":"10.1007/s10494-025-00638-7","DOIUrl":"10.1007/s10494-025-00638-7","url":null,"abstract":"<div><p>Ammonia combustion is gaining interest as a feasible alternative to traditional fossil fuels because of to the low environmental impact and as hydrogen and energy carrier. This study used Computational Fluid Dynamics (CFD) simulations to compare various turbulence models for premixed ammonia/hydrogen combustion in a swirl-stabilized burner. The primary aim was to identify the best turbulence model for accurately predicting the flow dynamics, combustion behaviour, and emissions profiles of ammonia/hydrogen fuel blends. The turbulence models evaluated were Large Eddy Simulation (LES), Realizable k-<span>(epsilon)</span>, Renormalization Group (RNG) k-<span>(epsilon)</span>, k-<span>(omega)</span> SST, and Reynolds Stress Model (RSM). On the LES side, a further comparison of two subgrid models (Smagorinsky-Lilly and WALE) was investigated. The Flamelet Generated Manifold (FGM) method was utilized with a detailed chemistry scheme taking into consideration all <span>(hbox {NO}_x)</span> reactions. To improve the prediction of <span>(hbox {NO}_x)</span> emissions, additional scalar transport equations for NO and <span>(hbox {NO}_2)</span> were included. This methodology aimed to be a balance between computational efficiency and the accuracy expected of detailed chemistry models. Validation was done with a swirl burner from Cardiff University’s Gas Turbine Research Centre. Results showed that all turbulence models accurately captured flame characteristics in terms of exhaust temperature and axial velocity with minor differences in the recirculation zones, where only the RSM model can predict the velocity trend as the LES simulation while other RANS models differ by at least 7 m/s. The temperature reached by the LES resulted 100 K higher than the other models in the flame zone. LES simulation can predict the emission value with an error of less than 10<span>(%)</span>. Moreover, the error related to emissions derived from the RANS simulations was not negligible, underestimating <span>(hbox {NO}_x)</span> emissions by about 35<span>(%)</span>. However, RSM model produced results that were closer to those derived from the high-fidelity LES when compared to the others RANS models, particularly in terms of flame thickness and emissions. It was concluded that it is mandatory to perform an unsteady analysis to reach reasonable results.</p></div>","PeriodicalId":559,"journal":{"name":"Flow, Turbulence and Combustion","volume":"114 Heat and Mass Transfer","pages":"1043 - 1063"},"PeriodicalIF":2.0,"publicationDate":"2025-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10494-025-00638-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143612165","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}

{"title":"Effects of Wall Temperature on Scalar and Turbulence Statistics During Premixed Flame–Wall Interaction Within Turbulent Boundary Layers","authors":"Sanjeev Kr. Ghai,&nbsp;Umair Ahmed,&nbsp;Nilanjan Chakraborty","doi":"10.1007/s10494-024-00603-w","DOIUrl":"10.1007/s10494-024-00603-w","url":null,"abstract":"<div><p>Direct numerical simulations (DNS) have been utilised to investigate the impact of different thermal wall boundary conditions on premixed V-flames interacting with walls in a turbulent channel flow configuration. Two boundary conditions are considered: isothermal walls, where the wall temperature is set either equal to the unburned mixture temperature or an elevated temperature, and adiabatic walls. An increase in wall temperature has been found to decrease the minimum flame quenching distance and increase the maximum wall heat flux magnitude. The analysis reveals notable differences in mean behaviours of the progress variable and non-dimensional temperature in response to thermal boundary conditions. At the upstream of the flame–wall interaction location, higher mean friction velocity values are observed for the case with elevated wall temperature compared to the other cases. However, during flame–wall interaction, friction velocity values decrease for isothermal walls but initially rise before decreasing for adiabatic walls, persisting at levels surpassing isothermal conditions. For all thermal wall boundary conditions, the mean scalar dissipation rates of the progress variable and non-dimensional temperature exhibit a decreasing trend towards the wall. Notably, in the case of isothermal wall boundary condition, a higher scalar dissipation rate for the non-dimensional temperature is observed in comparison to the scalar dissipation rate for the progress variable. Thermal boundary condition also has a significant impact on Reynolds stress components, turbulent kinetic energy, and dissipation rates, showing the highest magnitudes with isothermal case with elevated wall temperature and the lowest magnitude for the isothermal wall with unburned gas temperature. The findings of the current analysis suggest that thermal boundary conditions can potentially significantly affect trubulence closures in the context of Reynolds averaged Navier–Stokes simulations of premixed flame–wall interaction.</p></div>","PeriodicalId":559,"journal":{"name":"Flow, Turbulence and Combustion","volume":"114 2","pages":"421 - 448"},"PeriodicalIF":2.0,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10494-024-00603-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143430839","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}

{"title":"Blowout and Blowoff Limits of Confined Coaxial Ammonia/Hydrogen/Nitrogen-Air Flames with Variable Ammonia Fraction","authors":"Rajneesh Yadav,&nbsp;R. Santhosh","doi":"10.1007/s10494-024-00624-5","DOIUrl":"10.1007/s10494-024-00624-5","url":null,"abstract":"<div><p>The present experimental study reports first observations of stability, blowout, and blowoff characteristics of ammonia–hydrogen–nitrogen fuel blend flames with varying volumetric ammonia fractions (<span>({x}_{{NH}_{3}})</span>) in a coaxial combustor. The <span>({x}_{{NH}_{3}})</span> is varied from 20 to 80%. For flames of ammonia fraction equal to 70% (<span>({x}_{{NH}_{3}}=0.7)</span>), three types of flame transitions are observed within fuel flow Reynolds number (<span>({Re}_{f})</span>) of 40–575 as a coflow Reynolds number (<span>({Re}_{a})</span>) is increased in steps. Initially, the coflow air remains laminar and <span>({Re}_{a})</span> is increased gradually from laminar to turbulent limit. Different flame stabilization modes are characterized as burner-attached and lifted flame. The flame extinction modes are classified as <i>lifted-blowoff</i>, <i>attached-blowoff</i> and <i>attached-blowout</i> types. These flame transitions and stabilization characteristics are shown to be similar to methane flames. However, the <i>flame height</i> and <i>liftoff height</i> are shown to be different. The flames of fuel blends with ammonia fraction less than or equal to 60% (<span>({x}_{{NH}_{3}}le 0.6)</span>) are shown to behave fundamentally different from that of flames with <span>({x}_{{NH}_{3}}&gt;0.6)</span> (and also methane flames). Specifically, within the tested <span>({Re}_{f})</span> range, only one type of flame transition is observed as <span>({Re}_{a})</span> is systematically varied in the former as compared to three types observed in the latter. Also, with a decrease in ammonia fraction (and a corresponding increase in hydrogen percentage), the <i>liftoff limit</i>, <i>reattachment limit</i>, and <i>blowout limits</i> all are observed to increase. The effect of ammonia composition on <i>flame height</i> and <i>liftoff height</i> is also elaborated. The present study also provides empirical correlations (particularly for the low power flames) for predicting <i>blowout</i> and <i>blowoff limits</i> in both lifted and attached conditions for ammonia-hydrogen–nitrogen fuel blend flames.</p></div>","PeriodicalId":559,"journal":{"name":"Flow, Turbulence and Combustion","volume":"114 2","pages":"527 - 560"},"PeriodicalIF":2.0,"publicationDate":"2024-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143430830","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}

{"title":"Detection of Energetic Low Dimensional Subspaces in Spatio-Temporal Space in Turbulent Pipe Flow","authors":"Amir Shahirpour,&nbsp;Christoph Egbers,&nbsp;Jörn Sesterhenn","doi":"10.1007/s10494-024-00600-z","DOIUrl":"10.1007/s10494-024-00600-z","url":null,"abstract":"<div><p>Low dimensional subspaces are extracted out of highly complex turbulent pipe flow at <span>(Re_{tau }=181)</span> using a Characteristic Dynamic Mode Decomposition (CDMD). Having lower degrees of freedom, the subspaces provide a more clear basis to detect events which meet our understanding of large-scale coherent structures. To this end, a temporal sequence of state vectors from direct numerical simulations are rotated in space-time such that persistent dynamical modes on a hyper-surface are found travelling along its normal in space-time, which serves as the new time-like coordinate. The main flow features are captured with a minimal number of modes on a moving frame of reference whose velocity matches that of the most energetic scale. Reconstruction of the candidate modes in physical space gives the low rank model of the flow. The structures living in this subspace have long lifetimes, posses wide range of length-scales and travel at group velocities close to that of the moving frame of reference. The modes within this subspace are highly aligned, but are separated from the remaining modes by larger angles. We are able to capture the essential features of the flow like the spectral energy distribution and Reynolds stresses with a subspace consisting of about 10 modes. The remaining modes are collected in two further subspaces, which distinguish themselves by their axial length scale and degree of isotropy.</p></div>","PeriodicalId":559,"journal":{"name":"Flow, Turbulence and Combustion","volume":"114 Heat and Mass Transfer","pages":"1017 - 1041"},"PeriodicalIF":2.0,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10494-024-00600-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143612018","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}

{"title":"Numerical and Experimental Study on the Deflagration Characteristics of Premixed CO in a Tube with Obstacles","authors":"Qingqing Chen,&nbsp;Teng Li,&nbsp;Yao Wang,&nbsp;Xiaolin Wei,&nbsp;Liang Zhang","doi":"10.1007/s10494-024-00627-2","DOIUrl":"10.1007/s10494-024-00627-2","url":null,"abstract":"<div><p>As the main by-product of converter steelmaking process, converter gas has significant potential for energy recovery due to its high calorific value. However, there is a significant risk of explosion during the recycling process. In order to ensure the process safety of converter gas recovery and achieve efficient energy utilization, it is necessary to study the process of CO deflagration in the tube and prevent it. This article combines experiments and numerical simulations to study the effects of obstacles inside tube, water content in the air, and the length of the smooth section on CO deflagration characteristics. The results show that the propagation characteristics of flames in the smooth section are related to the flow field and have periodicity. The length of the smooth section does not significantly affect the maximum deflagration pressure. During the propagation of flames in the obstacle section, the acceleration effect of each obstacle on the flame is similar, and the deflagration becomes more and more intense as the number of obstacles increases. The peak value is reached at the last obstacle, about 0.72 MPa, and the flame speed can reach 672 m/s. The water content in the air has a significant impact on the maximum deflagration pressure of CO, as H₂O triggers a series of chain branching reactions. When the water content increases to 0.39%, the maximum deflagration pressure reaches its peak. In terms of numerical simulation, the reliability of the open-source combustion solver XiFoam was verified. The combustion, transport, and thermodynamic property parameters for premixed gas of CO and humid air were provided using Cantera. Finally, in order to avoid the occurrence of deflagration during the converter gas recovery process, it is necessary to strictly control its moisture content.</p></div>","PeriodicalId":559,"journal":{"name":"Flow, Turbulence and Combustion","volume":"114 2","pages":"561 - 583"},"PeriodicalIF":2.0,"publicationDate":"2024-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143430840","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}

{"title":"Relation Between 3 and 2D Wrinkling Factors in Turbulent Premixed Flames","authors":"Markus Klein,&nbsp;Nilanjan Chakraborty","doi":"10.1007/s10494-024-00622-7","DOIUrl":"10.1007/s10494-024-00622-7","url":null,"abstract":"<div><p>The magnitude of the wrinkled flame surface area in turbulent premixed flames divided by its projection in the direction of flame propagation, known as the wrinkling factor, is a fundamental quantity for the purpose of analysis and modelling premixed combustion, for example, in flame surface density based modelling approaches. According to Damköhler’s hypothesis it is closely related to the turbulent burning velocity, an equally important measure of the overall burning rate of a wrinkled flame. Three-dimensional evaluation of the area of highly wrinkled flames remains difficult and experiments are often based on planar measurements. As a result of this, model development and calibration require an extension of 2D measurements to 3D data. Different relations between 2D and 3D wrinkling factors are known in literature and will be discussed in the present work using a variety of direct numerical simulation (DNS) databases combined with theoretical arguments. It is shown, based on an earlier analysis, that the isotropic distribution of the surface area weighted probability density function of the angle between the normal vectors on the measurement plane and the flame surface, provides a very simple relationship, stating that the ratio between 3D and 2D flame surface area is given by <span>(4/pi )</span>, which is found to be in excellent agreement with DNS data of statistically planar turbulent premixed flames.</p></div>","PeriodicalId":559,"journal":{"name":"Flow, Turbulence and Combustion","volume":"114 2","pages":"519 - 526"},"PeriodicalIF":2.0,"publicationDate":"2024-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10494-024-00622-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143430878","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}

{"title":"LES Prediction of the Ignition Probability Map for a Model Aeronautical Spray Burner","authors":"Ernesto Sandoval Garzon,&nbsp;Cédric Mehl,&nbsp;Olivier Colin","doi":"10.1007/s10494-024-00617-4","DOIUrl":"10.1007/s10494-024-00617-4","url":null,"abstract":"<div><p>This study presents the computation of the ignition probability map of a model gas turbine, investigated experimentally at CORIA laboratory, using Large Eddy Simulation (LES). The simulations leverage the recently proposed TFM-AMR-I model, which is based on the Thickened Flame Model (TFM) formalism and enables a full flame resolution (i.e. no thickening) of the flame kernel in the initial instants of ignition. LES simulations of ignition are performed for 14 spatial points distributed in the combustion chamber, with 6 repetitions for each in order to obtain a reasonable estimate of ignition probabilities. Probabilities are adequately predicted for most of the selected points, with a typical error of 30 <span>(%)</span>. Nevertheless, the ignition probability is largely over-estimated at two locations where the mean diameter of liquid droplets is shown to be under-predicted, which may lead to too easy ignitions. Parametric variations show a satisfying robustness of the proposed approach with the two following key highlights: (i) the initial full flame resolution made possible by TFM-AMR-I is necessary, as an abrupt initial thickening leads to an artificial extinction; (ii) a correction of the over-sensitivity of the thickened flame to stretch, recently proposed in the literature, is necessary to predict ignition accurately.</p></div>","PeriodicalId":559,"journal":{"name":"Flow, Turbulence and Combustion","volume":"114 2","pages":"449 - 467"},"PeriodicalIF":2.0,"publicationDate":"2024-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143430797","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}

{"title":"Advantages of the Adoption of a Generalized Flame Displacement Velocity as a Central Element of Flamelet Theory","authors":"Hernan Olguin,&nbsp;Pascale Domingo,&nbsp;Luc Vervisch,&nbsp;Christian Hasse,&nbsp;Arne Scholtissek","doi":"10.1007/s10494-024-00618-3","DOIUrl":"10.1007/s10494-024-00618-3","url":null,"abstract":"<div><p>In combustion theory, flames are usually described in terms of the dynamics of iso-surfaces of a specific scalar. The flame displacement speed is then introduced as a local variable quantifying the progression of these iso-surfaces relative to the flow field. While formally defined as a scalar, the physical meaning of this quantity allows relating it with a vector pointing along the normal direction of the scalar iso-surface. In this work, this one-dimensional concept is extended by the introduction of a generalized flame displacement velocity vector, which is associated with the dynamics of iso-surfaces of two generic scalars, <span>(alpha )</span> and <span>(beta )</span>. It is then shown how a new flamelet paradigm can be built around this velocity vector, which leads to (i) an alternative procedure for the derivation of general flamelet equations, which is much simpler and more direct than the ones currently available in the literature, (ii) a very compact set of two-dimensional flamelet equations for the conditioning scalar gradients, <span>(g_{alpha } = |nabla alpha |)</span> and <span>(g_{beta } = |nabla beta |)</span>, which comprise several effects in few terms directly related to the projections of the generalized flame displacement velocity, and (iii) the possibility of characterizing different composition space coordinate systems through the same generalized flame displacement velocity. The proposed framework is discussed in the context of partially premixed combustion, emphasizing how its adoption can contribute to both the further development of 2D flamelet theory and its coupling with CFD codes.</p></div>","PeriodicalId":559,"journal":{"name":"Flow, Turbulence and Combustion","volume":"114 2","pages":"469 - 486"},"PeriodicalIF":2.0,"publicationDate":"2024-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143430798","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}