Flow, Turbulence and Combustion最新文献_第6页

Assessment of Thermal Boundary Models for Large Eddy Simulations of Natural Convection 自然对流大涡模拟的热边界模式评估

IF 2 3区工程技术

Flow, Turbulence and Combustion Pub Date : 2024-10-28 DOI: 10.1007/s10494-024-00594-8

Lise Ceresiat, Miltiadis V. Papalexandris

引用次数: 0

Analysis of Droplet Evaporation Dynamics Using Computational Singular Perturbation and Tangential Stretching Rate 用计算奇异摄动和切向拉伸率分析液滴蒸发动力学

IF 2 3区工程技术

Flow, Turbulence and Combustion Pub Date : 2024-10-17 DOI: 10.1007/s10494-024-00592-w

Lorenzo Angelilli, Riccardo Malpica Galassi, Pietro Paolo Ciottoli, Francisco E. Hernandez-Perez, Mauro Valorani, Hong G. Im

{"title":"Analysis of Droplet Evaporation Dynamics Using Computational Singular Perturbation and Tangential Stretching Rate","authors":"Lorenzo Angelilli, Riccardo Malpica Galassi, Pietro Paolo Ciottoli, Francisco E. Hernandez-Perez, Mauro Valorani, Hong G. Im","doi":"10.1007/s10494-024-00592-w","DOIUrl":"10.1007/s10494-024-00592-w","url":null,"abstract":"<div><p>Computational singular perturbation (CSP) has been successfully used in the analysis of complex chemically reacting flows by systematically identifying the intrinsic timescales and slow invariant manifolds that capture the essential subprocesses driving the dynamics of the system. In this article, the analytical and computational framework is applied for the first time to analyze the Lagrangian droplets undergoing evaporation and dispersion in the surrounding gases. First, a rigorous mathematical formulation is derived to adapt the CSP tools into the droplet dynamics equations, including the formal definition of the tangential stretching rate (TSR) that represents the explosive/dissipative nature of the system. A steady ammonia and a falling water droplet studies are then conducted to demonstrate the utility of the CSP methodology in identifying various physical mechanisms driving the evolution of the system, such as the distinction of thermal-driven and mass-driven regimes. Various definitions of the importance indices are also examined to provide in-depth analysis of different subprocesses and their interactions in modifying the droplet dynamics.</p></div>","PeriodicalId":559,"journal":{"name":"Flow, Turbulence and Combustion","volume":"114 1","pages":"275 - 298"},"PeriodicalIF":2.0,"publicationDate":"2024-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142995347","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

Assessment of the Partially Stirred Reactor Model for LES in a Swirl-Stabilized Turbulent Premixed Flame 旋流稳定湍流预混火焰中LES部分搅拌反应器模型的评估

IF 2 3区工程技术

Flow, Turbulence and Combustion Pub Date : 2024-10-15 DOI: 10.1007/s10494-024-00589-5

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

{"title":"Assessment of the Partially Stirred Reactor Model for LES in a Swirl-Stabilized Turbulent Premixed Flame","authors":"Fredherico Rodrigues, José M. García-Oliver, José M. Pastor, Daniel Mira","doi":"10.1007/s10494-024-00589-5","DOIUrl":"10.1007/s10494-024-00589-5","url":null,"abstract":"<div><p>This study presents an assessment of the Partially Stirred Reactor (PaSR) as a subgrid model for large eddy simulations (LES) of turbulent premixed combustion. The PaSR-LES approach uses a skeletal mechanism for methane/air combustion, and requires the transport of all the species, with a closure for the filtered source terms. The rate of progress for each reaction is given by the mixing and chemical time scales, which are computed from global flame parameters and a turbulent time scale respectively. This model is applied to a swirled combustor exhibiting a V-flame shape attached to the nozzle, subjected to heat loss. LES are carried out for two distinct equivalence ratios at atmospheric pressure. The flow fields and the thermochemical states from PaSR-LES are compared with the experimental data and solutions based on Flamelet Generated Manifolds (FGM). The results show good correlation with the experiments and FGM-LES, though also some sensitivity to the resolution. The approach also reproduces well the effect of heat loss, which is determined by the use of a chemical time scale given by a progress variable. Dedicated analysis of the swirl-stabilized flame on different regions is conducted evaluating the capabilities of the model to reproduce the burning velocity, flame shape and flame structure.</p></div>","PeriodicalId":559,"journal":{"name":"Flow, Turbulence and Combustion","volume":"114 1","pages":"359 - 386"},"PeriodicalIF":2.0,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142994330","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 Reformulation of the Laminar Kinetic Energy Model to Enable Multi-mode Transition Predictions 层流动能模型的重新表述以实现多模态跃迁预测

IF 2 3区工程技术

Flow, Turbulence and Combustion Pub Date : 2024-10-08 DOI: 10.1007/s10494-024-00590-y

Roberto Pacciani, Yuan Fang, Leonardo Metti, Michele Marconcini, Richard Sandberg

{"title":"A Reformulation of the Laminar Kinetic Energy Model to Enable Multi-mode Transition Predictions","authors":"Roberto Pacciani, Yuan Fang, Leonardo Metti, Michele Marconcini, Richard Sandberg","doi":"10.1007/s10494-024-00590-y","DOIUrl":"10.1007/s10494-024-00590-y","url":null,"abstract":"<div><p>The paper describes the development of a novel transition/turbulence model based on the laminar kinetic energy concept. The model is intended as a base framework for data-driven improvements. Starting from a previously developed framework, mainly aimed at separated-flow transition predictions, suitable terms for model generalization are identified and reformulated for handling different transition modes, namely bypass and separated-flow modes. The ideology for the definition of new terms has its roots in mixing phenomenological and correlation-based arguments, ensuring generality and flexibility and allowing a variety of lines of action for improving model components via machine-learning approaches. The model calibration, carried out with reference to flat plate test cases subjected to different pressure gradients and freestream turbulence levels, is discussed in detail. Although the constructed model is calibrated on a group of classic flat plat cases, the validation campaign, mostly carried out on gas turbine cascades, demonstrates its ability to predict transitional flows with engineering accuracy. Finally, while the model is not specifically developed for natural transition predictions, satisfactory predictions are obtained in scenarios with low freestream turbulence for flat plate and airfoil flows.</p></div>","PeriodicalId":559,"journal":{"name":"Flow, Turbulence and Combustion","volume":"114 1","pages":"81 - 116"},"PeriodicalIF":2.0,"publicationDate":"2024-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10494-024-00590-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142994695","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

Variable Resolution in Scale-Resolved Simulations of Turbulence 尺度分辨湍流模拟中的可变分辨率

IF 2 3区工程技术

Flow, Turbulence and Combustion Pub Date : 2024-10-03 DOI: 10.1007/s10494-024-00591-x

Magnus Carlsson, Stefan Wallin, Sharath Girimaji

{"title":"Variable Resolution in Scale-Resolved Simulations of Turbulence","authors":"Magnus Carlsson, Stefan Wallin, Sharath Girimaji","doi":"10.1007/s10494-024-00591-x","DOIUrl":"10.1007/s10494-024-00591-x","url":null,"abstract":"<div><p>A new formulation for scale-resolved simulations of turbulence with variable resolution (VR) is proposed. A delayed detached-eddy simulation (DDES) model based on the <span>(k-omega)</span> framework is extended with VR-terms representing the commutation terms arising from variable resolution defined in terms of the DDES length scale. The VR-terms are responsible for the exchange of turbulence kinetic energy between the resolved and unresolved partitioning of the computational representation of turbulent flow. The new formulation is implemented in a general-purpose CFD code and applied on two cases, namely, a mixing shear layer and a wall-mounted hump and have been compared with and combined with the baseline model and two additional grey-area mitigation (GAM) formulations. The proposed method is shown to provide the mechanism for the exchange of energy between unresolved and resolved representation of the flow and to enhance the transition from modelled to resolved turbulence and thus improve the prediction of the resolved Reynolds stresses, development of the vorticity thickness for the shear layer flow and the skin friction recovery length for the hump flow.</p></div>","PeriodicalId":559,"journal":{"name":"Flow, Turbulence and Combustion","volume":"115 Simulation and Measurements","pages":"105 - 125"},"PeriodicalIF":2.0,"publicationDate":"2024-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144100168","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 Survey on Control Techniques to Augment Compressible Jet Mixing 增强可压缩射流混合的控制技术综述

IF 2 3区工程技术

Flow, Turbulence and Combustion Pub Date : 2024-09-28 DOI: 10.1007/s10494-024-00588-6

Amit Krishnat Mali, Tamal Jana, Mrinal Kaushik, Gautam Choubey

{"title":"A Survey on Control Techniques to Augment Compressible Jet Mixing","authors":"Amit Krishnat Mali, Tamal Jana, Mrinal Kaushik, Gautam Choubey","doi":"10.1007/s10494-024-00588-6","DOIUrl":"10.1007/s10494-024-00588-6","url":null,"abstract":"<div><p>The mixing enhancement of a jet and its characteristics are essential for numerous aerospace applications, for example, reducing the infrared radiation of combat aircraft, mitigating noise in passenger aircraft, improving combustion characteristics in conventional jet, ramjet, and scramjet engines, producing vectored thrust for controlling spacecraft, missiles, and satellite. These applications led to studying the compressible jet mixing processes and strategies for controlling them. The mixing process is severely suppressed in high-speed flows (particularly when the jet Mach number is above 0.3) because of the compressibility effects. Jet mixing requires the development of augmentation strategies due to the short flow residence time (about a tenth of a millisecond). This study provides a comprehensive overview of the mixing improvement methods for compressible jets. It begins with an introduction to the compressible flow mixing layer. It examines several methods for enhancing jet mixing, such as active or passive control and unconventional mixing techniques like fluidic oscillators and mixing induced by shock waves. The passive flow control strategies make the flow more unstable and introduce large-scale vortices in the flow direction. The investigators studied the passive jet control configurations based on the above two approaches to increase mixing efficiency while maintaining a tolerable thrust loss and base drag. Active flow control is achieved by inducing instability but are only effective for appropriately selected values of actuating frequency, duty cycle, mass flow ratio, exit diameter of the actuating jet, location of actuators, etc.</p></div>","PeriodicalId":559,"journal":{"name":"Flow, Turbulence and Combustion","volume":"114 1","pages":"1 - 48"},"PeriodicalIF":2.0,"publicationDate":"2024-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142995694","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

Control of Shallow Water Flows Using an Optimization Procedure and Finite Element Analysis 用优化程序和有限元分析控制浅水流动

IF 2 3区工程技术

Flow, Turbulence and Combustion Pub Date : 2024-09-27 DOI: 10.1007/s10494-024-00587-7

Malú Grave, Renato Vaz Linn, Armando Miguel Awruch

{"title":"Control of Shallow Water Flows Using an Optimization Procedure and Finite Element Analysis","authors":"Malú Grave, Renato Vaz Linn, Armando Miguel Awruch","doi":"10.1007/s10494-024-00587-7","DOIUrl":"10.1007/s10494-024-00587-7","url":null,"abstract":"<div><p>A new approach using optimization techniques for controlling water flows is proposed in this work. The investigated problem is related to shallow water flows where a given time-evolution of outflow should be determined in order to control water elevation at some region. Typical applications are problems involving the control of movable barriers or water flowing through floodgates to prevent inundation. Usually, this type of problem is solved using gradient-based control techniques which can provide complex solutions that can be difficult to be implemented in practical situations. Here, the shape of the outflow discharge along time is predefined by a curve parametrization and used as design variable of an optimization problem. The shallow water equations are evaluated using the Finite Element Method (FEM). Numerical applications of water height control are presented and the different shapes of water outflow are investigated and discussed. As a result, the present framework can solve optimal flow control problems where an outflow discharge must satisfy a given type of variation along time.\u0000</p></div>","PeriodicalId":559,"journal":{"name":"Flow, Turbulence and Combustion","volume":"114 1","pages":"177 - 198"},"PeriodicalIF":2.0,"publicationDate":"2024-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142995831","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

On the Performances of Standard and Kinetic Energy Preserving Time-Integration Methods for Incompressible-Flow Simulations 不可压缩流模拟的标准保能和保动能时间积分方法的性能研究

IF 2 3区工程技术

Flow, Turbulence and Combustion Pub Date : 2024-09-26 DOI: 10.1007/s10494-024-00586-8

Marco Artiano, Carlo De Michele, Francesco Capuano, Gennaro Coppola

引用次数: 0

Analysis of Separation in the Roughness Sublayer Using DNS Data and DANS/DEM Modelling of Roughness Effects 基于DNS数据的粗糙度子层分离分析及粗糙度效应的DANS/DEM建模

IF 2 3区工程技术

Flow, Turbulence and Combustion Pub Date : 2024-09-24 DOI: 10.1007/s10494-024-00585-9

François Chedevergne, Jiasheng Yang, Alexander Stroh, Pourya Forooghi

{"title":"Analysis of Separation in the Roughness Sublayer Using DNS Data and DANS/DEM Modelling of Roughness Effects","authors":"François Chedevergne, Jiasheng Yang, Alexander Stroh, Pourya Forooghi","doi":"10.1007/s10494-024-00585-9","DOIUrl":"10.1007/s10494-024-00585-9","url":null,"abstract":"<div><p>From the recent DNS database (Yang in Journal of Fluid Mechanics) of channel flows with rough walls in the presence of heat transfer, the impact of the skewness of the roughness elevation map on the velocity and temperature profiles within the roughness sublayer is analysed. The separation zones observed near the wall in the sublayer are shown to play a significant role when the skewness is negative. The <span>(k-omega)</span>-based turbulence model (Chedevergne and Forooghi in Journal of Turbulence 21:463–482, 2020); (Chedevergne in Journal of Turbulence 22:713–734, 2021, Chedevergne in Journal of Turbulence 24: 36–56, 2023), capable of capturing roughness effects and incorporating the Double Averaged Navier–Stokes (DANS) equations and the Discrete Element Method (DEM), is tested against this DNS database, showing some limitations in the description of the roughness sublayers, especially for configurations with negative skewness. To reproduce the observations made in the DNS database, the pressure gradient imposed in the simulated channel using the DANS/DEM model is adjusted based on the distance to a reference wall in the roughness sublayers. Additionally, the increase in turbulent mixing observed in the DNS database for rough configurations with negative skewness is accounted for in the DANS/DEM model by modifying the source terms in the transport equations of the turbulent scalars with respect to the skewness, improving the prediction the roughness effects.</p></div>","PeriodicalId":559,"journal":{"name":"Flow, Turbulence and Combustion","volume":"114 Heat and Mass Transfer","pages":"713 - 735"},"PeriodicalIF":2.0,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143612305","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

Turbulence-Radiation Interaction Effects on Liquid Fuel Droplet Evaporation in Spraying Combustion Flow Using Large Eddy Simulation 湍流-辐射相互作用对喷雾燃烧流中液体燃料液滴蒸发的影响

IF 2 3区工程技术

Flow, Turbulence and Combustion Pub Date : 2024-09-19 DOI: 10.1007/s10494-024-00584-w

Mehdi Ghiyasi, Farzad Bazdidi-Tehrani

{"title":"Turbulence-Radiation Interaction Effects on Liquid Fuel Droplet Evaporation in Spraying Combustion Flow Using Large Eddy Simulation","authors":"Mehdi Ghiyasi, Farzad Bazdidi-Tehrani","doi":"10.1007/s10494-024-00584-w","DOIUrl":"10.1007/s10494-024-00584-w","url":null,"abstract":"<div><p>The objective of the present article is to address the influence of turbulence-radiation interactions (TRI) on parameters associated with the evaporation rate of fuel droplets in the spray combustion of a fuel mixture containing <span>({text{C}}_{10}{text{H}}_{22})</span> within a model combustor. Variables such as turbulence kinetic energy, TRI factors, and temperature distributions, particularly at the sub-grid scale, are investigated utilizing the large eddy simulation approach. Also, parameters including the pattern factor and <span>(text{NO})</span> concentration at the combustor outlet are assessed. The Eulerian approach to simulate the gaseous phase and the Lagrangian approach to model the liquid phase are employed. A two-way is used to couple their interactions, excluding the secondary breakup due to the Weber number being less than unity. The wall-adapting local eddy-viscosity model is adopted to simulate the eddy viscosity. The discrete ordinates method with the weighted-sum-of-gray-gases model is applied for thermal radiation calculating absorptivity and emissivity. The probability density function is utilized for modeling combustion. Results indicate that considering TRI facilitates the vaporization of fuel droplets due to accelerating the breakup process of the largest droplets by 3.36%, increasing their volumetric heat capacity by 4.50%, and reducing the penetration length by 10 mm. Furthermore, the maximum <span>(text{NO})</span> pollutant concentration at the combustor outlet decreases from 11.64 to 9.84 ppm, and PF reduces from 0.034 to 0.011 in the presence of both resolved and sub-grid scale TRI.</p></div>","PeriodicalId":559,"journal":{"name":"Flow, Turbulence and Combustion","volume":"114 1","pages":"323 - 358"},"PeriodicalIF":2.0,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142995501","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