Journal of Fluids Engineering最新文献_第2页

The Measured Flow at the Inlet of a Francis Turbine Runner Operating in Speed No-load Condition 在转速空载条件下运行的混流式水轮机转轮入口处的流量测量值

Journal of Fluids Engineering Pub Date : 2024-04-24 DOI: 10.1115/1.4065384

Araz Rezavand Hesari, Anthony Munoz, Maxime Coulaud, S. Houde, Yvan Maciel

{"title":"The Measured Flow at the Inlet of a Francis Turbine Runner Operating in Speed No-load Condition","authors":"Araz Rezavand Hesari, Anthony Munoz, Maxime Coulaud, S. Houde, Yvan Maciel","doi":"10.1115/1.4065384","DOIUrl":"https://doi.org/10.1115/1.4065384","url":null,"abstract":"\u0000 For Francis turbines, speed-no-load represents one of the most detrimental operating conditions, marked by significant pressure and strain fluctuations on the runner. Mitigating these fluctuations necessitates a comprehensive understanding and characterization of the flow phenomena responsible for their generation. This paper presents an experimental investigation of the flow at the inlet of a Francis turbine runner model operating in speed-no-load condition using high-speed stereoscopic and endoscopic particle image velocimetry. The measurements are made in a radial-azimuthal plane that covers the vaneless space and a large region in the interblade channel. This study marks the first-time measurement of critical flow phenomena at this operating point, performed in the runner. Instantaneous and average velocity fields are analyzed, along with other statistical data. The results confirm the stochastic nature of the flow at speed-no-load but also highlight the general structure of the flow observed in other studies. The high velocity fluctuations on the suction side are associated with a backflow extending into the vaneless space and a circulation zone occasionally generated by this backflow. Both phenomena are frequently present, but fluctuate stochastically. Additionally, two other circulation zones intermittently form on the pressure side of the blades. The presence of vortices, smaller than the circulation zones, near the blade's leading edge correlates with the backflow intensity.","PeriodicalId":504378,"journal":{"name":"Journal of Fluids Engineering","volume":"32 16","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140663298","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

Compressible Flow Through Flat Valve Seals at Microscale Displacements 微尺度位移下通过平阀密封件的可压缩流动

Journal of Fluids Engineering Pub Date : 2024-04-24 DOI: 10.1115/1.4065383

Nathan P. Hagstrom, Matthew L. Gallagher, Thomas R. Chase

引用次数: 0

A Multi-GPU Based Real-Time Large-Eddy Simulation of Urban Wind in Seoul 基于多 GPU 的首尔城市风实时大尺度模拟

Journal of Fluids Engineering Pub Date : 2024-04-16 DOI: 10.1115/1.4065303

Mingyu Yang, Geunwoo Oh, Tiantian Xu, Jungwoo Kim, Ji-Hoon Kang, Jung-Il Choi

引用次数: 0

Passively Enhanced Vortex-Induced Vibration Response of Side-by-Side Cylinders in Turbulent Flow 被动增强并排圆柱体在紊流中的涡流诱导振动响应

Journal of Fluids Engineering Pub Date : 2024-04-16 DOI: 10.1115/1.4065302

Y. H. Irawan, Syed Ahmad Raza, M. Chern

引用次数: 0

Morphological Features of a Splashing Drop Extracted Using Explainable AI 利用可解释的人工智能提取飞溅水滴的形态特征

Journal of Fluids Engineering Pub Date : 2024-04-16 DOI: 10.1115/1.4065304

Jingzu Yee, Daichi Igarashi, Shun Miyatake, A. Yamanaka, Yoshiyuki Tagawa

引用次数: 0

LES/Lagrangian-Particle-Simulation of a Supersonic Reactive Turbulent Planar Jet 超音速反应湍流平面喷流的 LES/拉格朗日粒子模拟

Journal of Fluids Engineering Pub Date : 2024-04-16 DOI: 10.1115/1.4065301

Jiabao Xing, Tomoaki Watanabe, K. Nagata

引用次数: 0

Direct Numerical Simulation On Millimeter-Sized Air Bubbles in Turbulent Channel Flow 湍流通道流中毫米级气泡的直接数值模拟

Journal of Fluids Engineering Pub Date : 2024-04-16 DOI: 10.1115/1.4065300

Sangwon Kim, Nobuyuki Oshima, H. Park, Y. Murai

引用次数: 0

Boundary-Layer Agitator for Advanced Convective Mixing 用于高级对流混合的边界层搅拌器

Journal of Fluids Engineering Pub Date : 2024-04-16 DOI: 10.1115/1.4065322

Robin Pham, Chung-Lung Chen

引用次数: 0

Aerodynamic Performance Evaluation of a Coaxial Octocopter Based on Taguchi Method 基于田口方法的同轴八旋翼飞行器空气动力性能评估

Journal of Fluids Engineering Pub Date : 2024-04-15 DOI: 10.1115/1.4065229

Evren Geydirici, Kuzey C. Derman, S. Cadirci

{"title":"Aerodynamic Performance Evaluation of a Coaxial Octocopter Based on Taguchi Method","authors":"Evren Geydirici, Kuzey C. Derman, S. Cadirci","doi":"10.1115/1.4065229","DOIUrl":"https://doi.org/10.1115/1.4065229","url":null,"abstract":"\u0000 The design and optimization of propellers for unmanned aerial vehicles (UAVs) are essential for optimal performance and high efficiency. This study presents a numerical investigation of the aerodynamic performance of coaxial octocopters using openfoam as flow solver. While the aerodynamic performance is affected by many parameters, the current study focuses on four main parameters: the propeller type, the horizontal and vertical separation distances between the propellers, and the ratio between the rotational speeds of the upper propeller and the lower one. To find the minimum number of simulations to be performed within defined limits, and reduce the number of computational fluid dynamics (CFD) simulations that cause high computational cost, Taguchi method was employed. In this study, average thrusts were calculated for the preliminary design of the octocopter by examining an isolated single propeller and dual- and quad propellers taking their rotation directions into account. The Taguchi design matrix revealed that for all cases investigated, the propeller type is the most dominant design parameter followed by the velocity ratio of the upper propeller to the lower one (nU/nL) and vertical (z/D) and horizontal (ℓ/D) orientation of coaxial propellers. However, it was shown that ℓ/D and z/D may play a significant role in vortex formation and pressure fluctuations which should be considered as design criteria for coaxial octocopters associated with flow attributes. The results showed that the aerodynamic performance parameters are not dependent on all the selected parameters, and demonstrated that the selected propeller designs improved aerodynamic performance.","PeriodicalId":504378,"journal":{"name":"Journal of Fluids Engineering","volume":"31 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140699445","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

Erosion Wear Analysis On Valve Cage of Cage-Typed Sleeve Control Valve for Coal Liquefaction 煤液化用笼式套筒调节阀阀笼的侵蚀磨损分析

Journal of Fluids Engineering Pub Date : 2024-04-12 DOI: 10.1115/1.4065306

An-qi Guan, Feng-ping Zhong, Chang Qiu, Zhi-jiang Jin, J. Qian

{"title":"Erosion Wear Analysis On Valve Cage of Cage-Typed Sleeve Control Valve for Coal Liquefaction","authors":"An-qi Guan, Feng-ping Zhong, Chang Qiu, Zhi-jiang Jin, J. Qian","doi":"10.1115/1.4065306","DOIUrl":"https://doi.org/10.1115/1.4065306","url":null,"abstract":"\u0000 Cage-typed sleeve control valve (CSCV) is the key basic equipment in direct coal liquefaction project. The working condition of CSCV has the characteristics of high pressure difference, high velocity and high solid content. There is a general problem of liquid-solid two-phase erosion wear in CSCV, which is easy to lead to the failure of internal structure in the valve cage. Therefore, it is necessary to study erosion wear characteristics of internal structure in the valve cage. Based on the actual situation of erosion wear in the valve cage, the simplified T-shaped flow path is designed, and the accuracy of the liquid-solid two-phase flow model and the erosion prediction model are verified; The flow characteristics and erosion wear characteristics of T-shaped flow path under different working conditions are studied; Based on the simulation results of different structural parameters and boundary conditions, the erosion wear of T-shaped flow path is predicted and calculated by response surface method, and the prediction formula of maximum erosion rate is obtained. The formula allows for the rapid determination of optimized flow path structural parameters to reduce damage to the valve from erosion and wear. This work can quickly predict the erosion wear rate of the key areas in the valve cage, which can provide a certain reference value for the life prediction and structural optimization of CSCV, and it can also benefit safety and maintenance of coal liquefaction system.","PeriodicalId":504378,"journal":{"name":"Journal of Fluids Engineering","volume":"7 5","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140708945","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