Flow, Turbulence and Combustion最新文献_第4页

Identification of Coherent Structures in Hydrogen-Enriched Swirl-Stabilised Flames Using Large-Eddy Simulations with Modal Decomposition Techniques 基于模态分解技术的大涡模拟富氢旋流稳定火焰相干结构识别

IF 2.2 3区工程技术

Flow, Turbulence and Combustion Pub Date : 2026-07-06 DOI: 10.1007/s10494-026-00769-5

Fredherico Rodrigues, José M. Pastor, José M. García-Oliver, Leonardo Pachano, Daniel Mira

{"title":"Identification of Coherent Structures in Hydrogen-Enriched Swirl-Stabilised Flames Using Large-Eddy Simulations with Modal Decomposition Techniques","authors":"Fredherico Rodrigues, José M. Pastor, José M. García-Oliver, Leonardo Pachano, Daniel Mira","doi":"10.1007/s10494-026-00769-5","DOIUrl":"10.1007/s10494-026-00769-5","url":null,"abstract":"<div><p>Large eddy simulations (LES) of an atmospheric swirled burner using a Partially Stirred Reactor (PaSR) closure are performed to investigate the hydrodynamic modes governing flow–flame interactions under hydrogen enrichment. Three technically premixed methane–air flames with increasing level of hydrogen are considered, Flame 1 (0% <span>(text{H}_2)</span>), Flame 2 (40% <span>(text{H}_2)</span>), and Flame 3 (50% <span>(text{H}_2)</span>). Simulations show good agreement with experimental data, particularly in terms of velocity fields and overall flame behaviour. Distinct flame topologies are observed, with Flame 1 exhibiting a lifted M-shaped structure and Flames 2 and 3 forming attached V-shaped flames. Proper Orthogonal Decomposition is applied to identify the dominant coherent structures. Flame 1 is strongly governed by a precessing vortex core (PVC), while Flames 2 and 3 exhibit weaker, more distributed structures. A secondary structure in Flame 1 is identified as a harmonic of the primary PVC, whereas analysis of the respective vortices in hydrogen-enriched Flames 2 and 3 suggests an independent nature. Overall, hydrogen enrichment modifies the strength and coherence of hydrodynamic structures and promotes a partial decoupling between mixing and flow dynamics.</p></div>","PeriodicalId":559,"journal":{"name":"Flow, Turbulence and Combustion","volume":"117 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2026-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148465094","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

Effects of In-Cylinder Flow and Injection Timing on Multi-Plane Analysis of Fuel-Air Mixture Distribution Under Cold Start Conditions in a Small-Bore Spark-Ignition Engine 缸内流量和喷射正时对小口径火花点火发动机冷启动工况下混合气分布多平面分析的影响

IF 2.2 3区工程技术

Flow, Turbulence and Combustion Pub Date : 2026-07-01 DOI: 10.1007/s10494-026-00772-w

Kartheeswaran Ayyanar, T. N. C. Anand, Mayank Mittal

{"title":"Effects of In-Cylinder Flow and Injection Timing on Multi-Plane Analysis of Fuel-Air Mixture Distribution Under Cold Start Conditions in a Small-Bore Spark-Ignition Engine","authors":"Kartheeswaran Ayyanar, T. N. C. Anand, Mayank Mittal","doi":"10.1007/s10494-026-00772-w","DOIUrl":"10.1007/s10494-026-00772-w","url":null,"abstract":"<div><p>Stringent emission regulations and the demand for improved fuel economy have driven advancements in spark-ignition engines. While direct injection offers better fuel economy and lean-burn combustion, its high cost and packaging complexity limit its adoption in small-bore engines for two- and three-wheelers. Port fuel injection remains preferred for its simpler design and compatibility with modern control strategies. However, during cold start, limited droplet evaporation and persistent wall films hinder combustible mixture formation, leading to misfires and increased unburned hydrocarbon emissions. Additionally, tumble development is restricted by an anticlockwise vortex beneath the intake valve, causing early decay during compression. To examine the influence of in-cylinder flow and injection timing on fuel–air mixture distribution across multiple planes, a computational fluid dynamics framework was developed and validated against experimental data for spray tip penetration (with and without wall impingement) and mixture distribution from planar laser-induced fluorescence. Results show that, in closed-valve injection, vaporized fuel is entrained by intake air and evenly distributed by tumble motion, producing a homogeneous mixture prior to combustion. In contrast, during open-valve injection, the spray enters asymmetrically through the intake valve and interacts with an already developed tumble vortex, confining vapor to one side and sustaining a stratified mixture throughout compression due to weak swirl motion. In addition, a statistical analysis based on the probability density function of the equivalence ratio was evaluated to assess mixture homogeneity across the sectional regions of the in-cylinder domain.</p></div>","PeriodicalId":559,"journal":{"name":"Flow, Turbulence and Combustion","volume":"117 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148380476","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

Estimating Hydrogen/Air Flame Acceleration Induced by 3D Flame Instabilities from 2D Simulations 从二维模拟中估计三维火焰不稳定性引起的氢/空气火焰加速度

IF 2.2 3区工程技术

Flow, Turbulence and Combustion Pub Date : 2026-07-01 DOI: 10.1007/s10494-026-00771-x

Cédric C. Mehl

{"title":"Estimating Hydrogen/Air Flame Acceleration Induced by 3D Flame Instabilities from 2D Simulations","authors":"Cédric C. Mehl","doi":"10.1007/s10494-026-00771-x","DOIUrl":"10.1007/s10494-026-00771-x","url":null,"abstract":"<div><p>The estimation of flame acceleration induced by thermo-diffusive and hydrodynamic instabilities is a key step toward developing accurate models for lean hydrogen combustion. One way to estimate this acceleration is to perform Direct Numerical Simulations (DNS) of laminar unstable flames. However, previous studies have shown that the 3D nature of instabilities significantly enhances the flame propagation speed compared to the 2D predictions. Systematically performing 3D simulations of laminar unstable flames remains out of reach due to prohibitive computational costs. In this work, a series of 2D and 3D DNS under various conditions are performed to establish a link between 2D and 3D flame wrinkling and stretch factors. Models are proposed that accurately estimate the 3D quantities from their 2D counterparts, leading in particular to an improved prediction of the 3D flame consumption speed. The robustness of these models is assessed using simulations performed with another chemical mechanism, and using published data obtained with another CFD solver. The prediction of the wrinkling and stretch factors is found to be highly robust. Overall, the resulting 3D flame consumption speed predictions are very accurate. These findings pave the way for improved subgrid-scale models of flame instabilities in RANS and LES frameworks.</p></div>","PeriodicalId":559,"journal":{"name":"Flow, Turbulence and Combustion","volume":"117 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10494-026-00771-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148380478","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

Agglomeration Dynamics of Non-Spherical Nanoparticles in Homogeneous Isotropic Turbulence 非球形纳米颗粒在均匀各向同性湍流中的团聚动力学

IF 2.2 3区工程技术

Flow, Turbulence and Combustion Pub Date : 2026-07-01 DOI: 10.1007/s10494-026-00765-9

Maximilian Karsch, Andreas Kronenburg

引用次数: 0

Impact of Structure-Preserving Discretizations on Compressible Wall-Bounded Turbulence of Thermally Perfect Gases 保结构离散化对热完美气体可压缩壁面湍流的影响

IF 2.2 3区工程技术

Flow, Turbulence and Combustion Pub Date : 2026-06-26 DOI: 10.1007/s10494-026-00768-6

Alessandro Aiello, Andrea Palumbo, Carlo De Michele, Gennaro Coppola

{"title":"Impact of Structure-Preserving Discretizations on Compressible Wall-Bounded Turbulence of Thermally Perfect Gases","authors":"Alessandro Aiello, Andrea Palumbo, Carlo De Michele, Gennaro Coppola","doi":"10.1007/s10494-026-00768-6","DOIUrl":"10.1007/s10494-026-00768-6","url":null,"abstract":"<div><p>Direct numerical simulations of compressible turbulent channel flow at supersonic and hypersonic Mach numbers are performed using a thermally perfect gas model for <span>(textrm{CO}_2)</span>. The objective is to assess the role of structure-preserving discretizations of the convective terms in high-enthalpy regimes, with particular emphasis on entropy conservation, kinetic-energy preservation, and consistency with the thermodynamic closure. The comparative analysis of various formulations examines their impact on robustness, thermodynamic fluctuations, and turbulence statistics across a range of Mach numbers. Differences among formulations are found to originate primarily in the treatment of thermodynamic variables and progressively influence the dynamical fields as compressibility effects intensify. In particular, the coupling between entropy consistency and pressure discretization is shown to affect Reynolds stresses and mean flow properties in high-speed regimes. Overall, the results indicate that consistency between the numerical formulation and the thermodynamic model contributes significantly to the reliable simulation of high-enthalpy compressible turbulence. The study systematically assesses entropy-conservative discretizations for thermally perfect gases in wall-bounded flows and examines their impact on thermodynamic-dynamic coupling at high Mach numbers.</p></div>","PeriodicalId":559,"journal":{"name":"Flow, Turbulence and Combustion","volume":"117 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2026-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10494-026-00768-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148323284","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

DNS and LES of the Flow Over Periodic Hills with a Remeshed Vortex Method 基于重网格涡旋法的周期性山丘流动的DNS和LES

IF 2.2 3区工程技术

Flow, Turbulence and Combustion Pub Date : 2026-06-26 DOI: 10.1007/s10494-026-00767-7

Marthe de Crouy-Chanel, Chloé Mimeau, Iraj Mortazavi, Alessandro Mariotti, Maria Vittoria Salvetti

{"title":"DNS and LES of the Flow Over Periodic Hills with a Remeshed Vortex Method","authors":"Marthe de Crouy-Chanel, Chloé Mimeau, Iraj Mortazavi, Alessandro Mariotti, Maria Vittoria Salvetti","doi":"10.1007/s10494-026-00767-7","DOIUrl":"10.1007/s10494-026-00767-7","url":null,"abstract":"<div><p>This study evaluates the capability of a Remeshed Vortex Method (RVM) to accurately simulate complex wall-bounded turbulent flows by performing both Direct Numerical Simulations (DNS) and Large Eddy Simulations (LES) of the flow over periodic hills. The RVM stems from Lagrangian Vortex methods, discretizing the flow fields on numerical particles, where a remeshing procedure is applied to redistribute the particles onto a Cartesian grid in order to control the interparticle distance. In DNS, different algorithmic configurations inherent to the RVM’s remeshing procedure are explored. The RVM shows good accuracy and computational efficiency in terms of mesh resolution and time steps compared to the DNS results reported in literature, despite the limitation of using a uniform Cartesian grid. In the LES framework, first a systematic analysis of the directional splitting sequence in the RVM algorithm for anisotropic flows allows us to select a priori the optimal direction ordering in the operators splitting procedure. Secondly, different subgrid-scale models are selected and assessed, including some models previously evaluated and calibrated in a HIT configuration. Among these, the Variational Multiscale (VMS) eddy-viscosity models and the Spectral Vanishing Viscosity (SVV) approaches, which introduce dissipation only at the smallest resolved vorticity scales, are found to be the most suitable for use with the RVM. In particular, the calibrated VMS Smagorinsky model shows the best performance, confirming our previous findings on the robustness of the model calibration.</p></div>","PeriodicalId":559,"journal":{"name":"Flow, Turbulence and Combustion","volume":"117 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2026-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148323285","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

Generation of Lambda Shaped Flow Region in Laminar Gas Jet Induced by Plasma Propagation 等离子体传播诱导层流气体射流中λ形流区的产生

IF 2.2 3区工程技术

Flow, Turbulence and Combustion Pub Date : 2026-06-16 DOI: 10.1007/s10494-026-00766-8

Asma Begum, Tatsuo Ishijima, M. R. Pervez, Mohammed Anwer

{"title":"Generation of Lambda Shaped Flow Region in Laminar Gas Jet Induced by Plasma Propagation","authors":"Asma Begum, Tatsuo Ishijima, M. R. Pervez, Mohammed Anwer","doi":"10.1007/s10494-026-00766-8","DOIUrl":"10.1007/s10494-026-00766-8","url":null,"abstract":"<div><p>Atmospheric Pressure Plasma Jet (APPJ) accelerating following the fluid flow is responsible for the modification of the gas flow dynamics. This study investigates the gas flow dynamics in the presence of non-thermal atmospheric pressure plasma jets (APPJs), focusing on the Greek letter lambda shape transition region between laminar and vortex flow regimes. Using Schlieren imaging, we analyzed flow characteristics at different gas flow rates (2 slm, 3 slm, and 4 slm), identified distinct flow regions and the onset of vortex. A small to moderate flow instability around plasma jet is observed. Key parameters, including Reynolds number, electron density, electron drift velocity (~10<sup>5</sup> m/s) and electrohydrodynamic (EHD) forces, are evaluated experimentally to understand their roles in flow instability. Electron and gas temperature estimated from emission data are ~3500 K and ~350 K, respectively. The plasma jet extends past the 50% air admixture on the helium channel, resulting in a lambda-shaped flow. Additionally, variations in the electric field contribute to the instability of the plasma jet is justified.</p></div>","PeriodicalId":559,"journal":{"name":"Flow, Turbulence and Combustion","volume":"117 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2026-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148281170","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 Characteristics of Wall Synthetic Jet Flowing Over a Circular Cylinder 壁面合成射流在圆柱上的流动特性

IF 2.4 3区工程技术

Flow, Turbulence and Combustion Pub Date : 2026-06-08 DOI: 10.1007/s10494-026-00762-y

Rion Yokota, Takaya Hiruma, Koichi Nishibe, Kotaro Sato

{"title":"Flow Characteristics of Wall Synthetic Jet Flowing Over a Circular Cylinder","authors":"Rion Yokota, Takaya Hiruma, Koichi Nishibe, Kotaro Sato","doi":"10.1007/s10494-026-00762-y","DOIUrl":"10.1007/s10494-026-00762-y","url":null,"abstract":"<div><p>When jet-based flow control, such as stall control and fluidic thrust vectoring, is employed, jet nozzles are commonly installed near a convex-curved surface. Numerous researchers have investigated the most fundamental curved-wall continuous jet. For synthetic jets, although numerous applied studies exist, fundamental investigations on cylindrical walls remain scarce. Synthetic jets have zero net mass flux; the vortex pair generated during the expulsion phase dominates the suction phase and establishes a time-averaged flow downstream. This study clarifies how a cylindrical surface influences the vortex pair and the resulting mean flow. We performed flow visualization using Particle Image Velocimetry and surface-pressure measurements for a synthetic jet issuing tangentially over a cylindrical surface. We examined the effects of stroke length (the distance fluid particle travels at the representative velocity during one oscillation period) and radius of curvature on the flow. The boundary layer on the wall organized into discrete vortices linked to the dimensionless stroke length, and both the time-averaged pressure distribution and separation point on the cylindrical surface depended on it. Moreover, the vortex street and time-averaged-flow characteristics can be parameterized using a nominal dimensionless stroke based on the radius of curvature rather than the slot width typically used as the representative length.</p></div>","PeriodicalId":559,"journal":{"name":"Flow, Turbulence and Combustion","volume":"117 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2026-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10494-026-00762-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148236598","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

Advances in Combustion Research 燃烧研究进展

IF 2.4 3区工程技术

Flow, Turbulence and Combustion Pub Date : 2026-06-04 DOI: 10.1007/s10494-026-00760-0

Mohy S. Mansour, Andrea D’Anna

引用次数: 0

Usage of Green Spectrum-Based Temperature Sensitive Paint for Heat Transfer Measurement 基于绿色光谱的温敏涂料在传热测量中的应用

IF 2.4 3区工程技术

Flow, Turbulence and Combustion Pub Date : 2026-06-03 DOI: 10.1007/s10494-026-00764-w

Haricharan Pippari, Keesanth Singh Chandrasekaran, Sathesh Mariappan

{"title":"Usage of Green Spectrum-Based Temperature Sensitive Paint for Heat Transfer Measurement","authors":"Haricharan Pippari, Keesanth Singh Chandrasekaran, Sathesh Mariappan","doi":"10.1007/s10494-026-00764-w","DOIUrl":"10.1007/s10494-026-00764-w","url":null,"abstract":"<div><p>Jet impingement cooling is a traditional method that provides higher heat transfer rates for cooling components in many engineering applications to increase the life and efficiency of the components. The present work focuses on the experimental measurement of heat transfer on a flat plate, cooled by an obliquely impinging low-speed jet using a recently developed green-spectrum-based temperature-sensitive paint (TSP). The TSP is used to measure temperature distributions on the hot plate (at 333 K) when subjected to a relatively cold jet (298 K). Surface temperature data are extracted from the TSP luminescence emission captured by a charge-coupled device camera. The experiments are performed for different impingement angles and jet exit Reynolds numbers. Heat flux is calculated using the modified Cook-Felderman method, which employs a semi-infinite and finite thickness model for the hot plate. The obtained heat flux is compared with the commercially available differential thermophile heat flux (point) sensor. Temporal self-similarity in heat flux is observed. The corresponding normalized heat flux is identified. A feedforward artificial neural network is trained to link the normalized heat flux distribution with the experimental parameters.</p></div>","PeriodicalId":559,"journal":{"name":"Flow, Turbulence and Combustion","volume":"117 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2026-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148172278","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