Fluids Pub Date : 2023-10-27 DOI: 10.3390/fluids8110285

Ali Shirinzad, Khodr Jaber, Kecheng Xu, Pierre E. Sullivan

引用次数: 0

Rendering Maxwell Equations into the Compressible Inviscid Fluid Dynamics Form 将麦克斯韦方程组转换为可压缩无粘流体动力学形式

Fluids Pub Date : 2023-10-26 DOI: 10.3390/fluids8110284

Peter Vadasz

引用次数: 0

Settling Flow Details in the Flash Smelting Furnace—A CFD-DEM Simulation Study 闪速熔炼炉沉降流程细节CFD-DEM模拟研究

Fluids Pub Date : 2023-10-23 DOI: 10.3390/fluids8100283

Jani-Petteri Jylhä, Ari Jokilaakso

{"title":"Settling Flow Details in the Flash Smelting Furnace—A CFD-DEM Simulation Study","authors":"Jani-Petteri Jylhä, Ari Jokilaakso","doi":"10.3390/fluids8100283","DOIUrl":"https://doi.org/10.3390/fluids8100283","url":null,"abstract":"The flash smelting furnace has previously been simulated using computational fluid dynamics (CFD). A new approach is to combine CFD and the discrete element method (DEM) for more detailed simulations of the different phenomena that occur as copper matte droplets settle through a slag layer. One of the most important phenomena found is the formation of a channeling flow which carries matte droplets faster through the slag. However, such phenomena cannot be directly observed in the flash smelting furnace settler due to the extreme temperatures of the opaque molten slag inside the furnace, therefore alternative methods are required for validating the phenomenon. In this work, the simulated channeling flow is validated with a sphere–oil model. The phenomenon was similar in all of the studied cases, although in the experimental setup the spheres settled faster in the oil model than in the simulations. The differences were most likely caused by the cohesion of the spheres and slight differences in the properties provided by the manufacturer and real properties for the oil and the spheres, and by the fact that simulation ignores surface tension and changing air–oil and water–oil interfaces.","PeriodicalId":12397,"journal":{"name":"Fluids","volume":"338 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135366752","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A Detailed Numerical Study on Aerodynamic Interactions of Tandem Wheels on a Generic Vehicle 通用车辆串联车轮气动相互作用的详细数值研究

Fluids Pub Date : 2023-10-20 DOI: 10.3390/fluids8100281

Radoje Radovic, Fatemeh Salehi, Sammy Diasinos

{"title":"A Detailed Numerical Study on Aerodynamic Interactions of Tandem Wheels on a Generic Vehicle","authors":"Radoje Radovic, Fatemeh Salehi, Sammy Diasinos","doi":"10.3390/fluids8100281","DOIUrl":"https://doi.org/10.3390/fluids8100281","url":null,"abstract":"Wheels contribute significantly to the aerodynamic performance of ground vehicles. Many studies have focused on investigating a single wheel either in isolation or in a wheelhouse. However, there has been less focus on the flow field around a rear wheel, especially when considering varying proximity to the front wheel, despite its importance on aerodynamic forces. In this study, a generic reference body is modified and fitted with a rear wheel within a wheelhouse and analysed while the wheel spacing varies. Reynolds-Averaged Navier–Stokes (RANS) modelling was employed to allow for multiple variations to be considered and the model produced results in good agreement with experimental results. The results confirm that two upper rear wheelhouse outflow vortices are only present when the wheel spacing is short. It was found that the drag values were minimal for the wheel spacing at a critical distance of 1.5 wheel diameters. At this wheel spacing, the formation of the outboard jetting vortex is prevented at the rear wheel, and hence, the rear wheel drag is reduced by more than 10%. Any further reduction in the spacing does not provide any drag benefits. Also, the outflow from the front wheelhouse is projected further away from the body, drawing flow from the rear wheelhouse into the outboard jetting vortex.","PeriodicalId":12397,"journal":{"name":"Fluids","volume":"87 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135569201","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A Comparison of Newtonian and Non-Newtonian Models for Simulating Stenosis Development at the Bifurcation of the Carotid Artery 模拟颈动脉分叉处狭窄发展的牛顿和非牛顿模型的比较

Fluids Pub Date : 2023-10-20 DOI: 10.3390/fluids8100282

Aikaterini C. Stamou, Jovana Radulovic, James M. Buick

引用次数: 0

Numerical Simulation of Taylor—Couette—Poiseuille Flow at Re = 10,000 Re = 10,000时Taylor-Couette-Poiseuille流动的数值模拟

Fluids Pub Date : 2023-10-19 DOI: 10.3390/fluids8100280

Andrey Gavrilov, Yaroslav Ignatenko

引用次数: 0

Editorial Summary: Boundary Layer Processes in Geophysical/Environmental Flows 地球物理/环境流动中的边界层过程

Fluids Pub Date : 2023-10-19 DOI: 10.3390/fluids8100279

Joseph Kuehl

引用次数: 0

Surface Roughness in RANS Applied to Aircraft Ice Accretion Simulation: A Review RANS的表面粗糙度在飞机冰积模拟中的应用综述

Fluids Pub Date : 2023-10-15 DOI: 10.3390/fluids8100278

Kevin Ignatowicz, François Morency, Héloïse Beaugendre

{"title":"Surface Roughness in RANS Applied to Aircraft Ice Accretion Simulation: A Review","authors":"Kevin Ignatowicz, François Morency, Héloïse Beaugendre","doi":"10.3390/fluids8100278","DOIUrl":"https://doi.org/10.3390/fluids8100278","url":null,"abstract":"Experimental and numerical fluid dynamics studies highlight a change of flow structure in the presence of surface roughness. The changes involve both wall heat transfer and skin friction, and are mainly restricted to the inner region of the boundary layer. Aircraft in-flight icing is a typical application where rough surfaces play an important role in the airflow structure and the subsequent ice growth. The objective of this work is to investigate how surface roughness is tackled in RANS with wall resolved boundary layers for aeronautics applications, with a focus on ice-induced roughness. The literature review shows that semi-empirical correlations were calibrated on experimental data to model flow changes in the presence of roughness. The correlations for RANS do not explicitly resolve the individual roughness. They principally involve turbulence model modifications to account for changes in the velocity and temperature profiles in the near-wall region. The equivalent sand grain roughness (ESGR) approach emerges as a popular metric to characterize roughness and is employed as a length scale for the RANS model. For in-flight icing, correlations were developed, accounting for both surface geometry and atmospheric conditions. Despite these research efforts, uncertainties are present in some specific conditions, where space and time roughness variations make the simulations difficult to calibrate. Research that addresses this gap could help improve ice accretion predictions.","PeriodicalId":12397,"journal":{"name":"Fluids","volume":"67 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136185075","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Using Computation Fluid Dynamics to Determine Oil Droplet Breakup Parameters during Emulsion Atomization with Pressure Swirl Nozzles 用计算流体动力学方法确定压力旋流喷嘴乳化雾化过程中油滴破碎参数

Fluids Pub Date : 2023-10-14 DOI: 10.3390/fluids8100277

Miguel Ángel Ballesteros Martínez, Volker Gaukel

{"title":"Using Computation Fluid Dynamics to Determine Oil Droplet Breakup Parameters during Emulsion Atomization with Pressure Swirl Nozzles","authors":"Miguel Ángel Ballesteros Martínez, Volker Gaukel","doi":"10.3390/fluids8100277","DOIUrl":"https://doi.org/10.3390/fluids8100277","url":null,"abstract":"A wide range of commercial powdered products are manufactured by spray drying emulsions. Some product properties are dependent on the oil droplet size, which can be affected by fluid mechanics inside the spray nozzle. However, most of the key flow parameters inside the nozzles are difficult to measure experimentally, and theoretical estimations present deviations at high shear rates and viscosities. Therefore, the purpose of this study was to develop a computational model that could represent the multiphase flow in pressure swirl nozzles and could determine the deformation stresses and residence times that oil droplets experience. The multiphase flow was modelled using the Volume-of-Fluid method under a laminar regime. The model was validated with experimental data using the operating conditions and the spray angle. The numerically calculated shear stresses were found to provide a better prediction of the final oil droplet size than previous theoretical estimations. A two-step breakup mechanism inside of the nozzle was also proposed. Additionally, some of the assumptions used in the theoretical estimations could not be confirmed for the nozzles investigated: No complete air core developed inside of the nozzle during atomization, and the shear stress at the nozzle outlet is not the only stress that can affect oil droplet size. Elongation stresses cannot be neglected in all cases.","PeriodicalId":12397,"journal":{"name":"Fluids","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135804380","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Numerical Study of the Influence of the Critical Reynolds Number on the Aerodynamic Characteristics of the Wing Airfoil 临界雷诺数对翼型气动特性影响的数值研究

Fluids Pub Date : 2023-10-13 DOI: 10.3390/fluids8100276

Anna Utkina, Andrey Kozelkov, Roman Zhuchkov, Dmitry Strelets

引用次数: 0

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