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}
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}
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}
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}
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}
{"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}
Aravind Ramachandran, Rajat Soni, Markus Roßmann, Marc Klawitter, Clemens Gößnitzer, Jakob Woisetschläger, Anton Tilz, Gerhard Pirker, Andreas Wimmer
{"title":"High Speed Particle Image Velocimetry in a Large Engine Prechamber","authors":"Aravind Ramachandran, Rajat Soni, Markus Roßmann, Marc Klawitter, Clemens Gößnitzer, Jakob Woisetschläger, Anton Tilz, Gerhard Pirker, Andreas Wimmer","doi":"10.1007/s10494-024-00572-0","DOIUrl":"10.1007/s10494-024-00572-0","url":null,"abstract":"<div><p>Planar velocity measurements using the particle image velocimetry technique have been performed at a repetition rate of 10 kHz in the prechamber of a large bore gas engine mounted on a rapid compression machine (RCM), to visualize the velocity fields in the non-reacting gas flow during a compression stroke. The prechamber investigated in this work is a prototype with modifications made to facilitate optical access, and it is mounted axially on the RCM combustion chamber. The parameters of the compression stroke in the RCM are set to achieve a compression ratio of 10. After removing outlying data based on pressure and piston displacement curves, PIV data from compression strokes were analyzed. The time-resolved velocity fields capture the formation and motion of a tumble vortex in the imaged plane. Mean flow fields obtained by phase averaging across the datasets are presented, showing the development of the flow field in the prechamber throughout the compression stroke. The data obtained will be used to validate CFD simulations.</p></div>","PeriodicalId":559,"journal":{"name":"Flow, Turbulence and Combustion","volume":"113 4","pages":"1003 - 1023"},"PeriodicalIF":2.0,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10494-024-00572-0.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142178757","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}
Ehsan Habibi Siyahpoosh, Mohammad Reza Ansari, Khosro Sheikhi, Sadegh Ahmadi
{"title":"Numerical Simulation of Hydrodynamic Noises during Bubble Rising Process","authors":"Ehsan Habibi Siyahpoosh, Mohammad Reza Ansari, Khosro Sheikhi, Sadegh Ahmadi","doi":"10.1007/s10494-024-00582-y","DOIUrl":"10.1007/s10494-024-00582-y","url":null,"abstract":"<div><p>Noise analysis is one of the most efficient and newest methods to investigate dynamic behaviors of any system. In this study, hydrodynamic noises of a single bubble are scrutinized by applying Curle's acoustic analogy as implemented in OpenFoam® v2012. Meanwhile, a new solver (interAcousticFoam) is developed to hydroacoustically evaluate the noise sources. A three-dimensional transient incompressible two-phase flow model is simulated based on the hybrid method (the volume of fluid (VOF) method and Curle’s analogy method) to predict the acoustic emission characteristics of the single bubble. The pressure fluctuations are measured by adding the scale adaptive simulation (SAS) concept to the unsteady reynolds-averaged Navier–Stokes (URANS) simulation, which resulted in precise extraction of the flow fluctuations and thus the accurate simulation of the acoustic pressure fluctuations is achieved. Additionally, the analysis of the noise production mechanism is developed by implementing the Acoustic Perturbation Equations (APE) in the new solver. An alternative version of the acoustic technique is proposed to estimate the acoustic pressure fluctuations during the bubble rising process at an orifice submerged in water. The dynamic responses and the time–frequency analyses of the bubble indicate that the numerical simulation covers the main features of the principal acoustic components and can successfully predict the natural frequency of the bubble’s dynamic behaviors.</p></div>","PeriodicalId":559,"journal":{"name":"Flow, Turbulence and Combustion","volume":"114 1","pages":"299 - 322"},"PeriodicalIF":2.0,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142178756","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":"The Aerodynamic Breakup and Interactions of Evaporating Water Droplets with a Propagating Shock Wave","authors":"Zhiwei Huang, Ruixuan Zhu, Martin Davy","doi":"10.1007/s10494-024-00581-z","DOIUrl":"10.1007/s10494-024-00581-z","url":null,"abstract":"<div><p>The aerodynamic breakup physics of water droplets in shock–laden flows are investigated in this study. One-dimensional numerical simulations based on a hybrid Eulerian–Lagrangian approach are performed to study the interactions between propagating shock waves and monodispersed evaporating water droplets with breakup. Two-way coupling for the interphase exchanges of mass, momentum, and energy is considered for the two-phase gas–droplet flows. Parametric study on the droplet evaporation, motion, heating, and breakup dynamics is performed, through considering initial droplet diameters of 20–80 μm and incident shock Mach numbers (<span>({M}_{0})</span>) of 1.3–4.0. The resultant initial droplet Weber numbers range between 10.0 and 4758.3, which cover the bag, bag-and-stamen, sheet stripping, and wave crest stripping breakup modes. The distance for breakup completion behind the transmitted shock and the resultant diameter all decrease with increased incident shock Mach number. When <span>({M}_{0})</span> ≥ 2.1, shock attenuation is also intensified with droplet diameter besides volume fraction under fixed droplet mass loading. Furthermore, net momentum transfer from the droplets to carrier gas (instead of in the opposite direction as extensively observed) occurs when <span>({M}_{0})</span> ≥ 2.1, mainly caused by the high temperature of post-shock gas and small diameter of broken droplets under strong incident shocks. A scale analysis shows that the momentum and energy transfer rates because of droplet evaporation have comparable magnitudes respectively to the counterparts from drag force and convective heat transfer. This is particularly true in the regions far off the shock front when <span>({M}_{0})</span> ≥ 2.1.</p></div>","PeriodicalId":559,"journal":{"name":"Flow, Turbulence and Combustion","volume":"114 1","pages":"243 - 273"},"PeriodicalIF":2.0,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142178758","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}
Wencan Wu, Luis Laguarda, Davide Modesti, Stefan Hickel
{"title":"Passive Control of Shock-Wave/Turbulent Boundary-Layer Interaction Using Spanwise Heterogeneous Roughness","authors":"Wencan Wu, Luis Laguarda, Davide Modesti, Stefan Hickel","doi":"10.1007/s10494-024-00580-0","DOIUrl":"https://doi.org/10.1007/s10494-024-00580-0","url":null,"abstract":"<p>A novel passive flow-control method for shock-wave/turbulent boundary-layer interactions (STBLI) is investigated. The method relies on a structured roughness pattern constituted by streamwise-aligned ridges. Its effectiveness is assessed with wall-resolved large-eddy simulations of the interaction of a Mach 2 turbulent boundary layer flow with an oblique impinging shock with shock angle <span>(40^circ)</span>. The structured roughness pattern, which is fully resolved by a cut-cell based immersed boundary method, covers the entire computational domain. Results show that this rough surface induces large-scale secondary streamwise vortices, which energize the boundary layer by transporting high-speed fluid closer to the wall. A parametric study is performed to investigate the effect of the spacing between the ridges. This investigation is further substantiated through spectral analysis and sparsity-promoting dynamic mode decomposition. We find that ridges with small spacing effectively mitigate the low-frequency unsteadiness of STBLI and slightly reduce total-pressure loss.</p>","PeriodicalId":559,"journal":{"name":"Flow, Turbulence and Combustion","volume":"14 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142178759","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}