Journal of Fluids Engineering-Transactions of the Asme最新文献

A Method to Determine Bubble Distribution in Liquid Using Data of Inverse Acoustical Scattering 利用声波反散射数据确定液体中气泡分布的方法

3区工程技术

Journal of Fluids Engineering-Transactions of the Asme Pub Date : 2023-11-07 DOI: 10.1115/1.4064005

Eduard Amromin

引用次数: 0

Orifice Jet Curvature And Its Interaction With A Row Of Short Pin-Fins 孔板射流曲率及其与一排短鳍的相互作用

3区工程技术

Journal of Fluids Engineering-Transactions of the Asme Pub Date : 2023-11-07 DOI: 10.1115/1.4064008

Sjouke Schekman, Tongbeum Kim

引用次数: 0

Effect of Perforation on Vortex Characteristics of a Micro-Vortex Generator Mounted on a Flat Plate 穿孔对平板微涡发生器涡特性的影响

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Journal of Fluids Engineering-Transactions of the Asme Pub Date : 2023-11-07 DOI: 10.1115/1.4064009

Abhishek Khare, Shashank Khurana

引用次数: 0

Energy Contribution Study Of Blade Cavitation Control By Obstacles In A Waterjet Pump Based On mPOD And EEMD 基于mPOD和EEMD的射流泵障碍物控制叶片空化的能量贡献研究

3区工程技术

Journal of Fluids Engineering-Transactions of the Asme Pub Date : 2023-11-07 DOI: 10.1115/1.4064006

Guoshou Zhao, Ning Liang, Qianqian Li, Wei Dong, Linlin Cao, Dazhuan Wu

{"title":"Energy Contribution Study Of Blade Cavitation Control By Obstacles In A Waterjet Pump Based On mPOD And EEMD","authors":"Guoshou Zhao, Ning Liang, Qianqian Li, Wei Dong, Linlin Cao, Dazhuan Wu","doi":"10.1115/1.4064006","DOIUrl":"https://doi.org/10.1115/1.4064006","url":null,"abstract":"Abstract It has been confirmed that the passive obstacles would substantially depress the leading-edge cavitation in a waterjet pump. Combined with the experiments and numerical simulations, this work revisits blade cavitation evolutions to demonstrate the stabilizing effects of obstacles on cavitation unsteadiness. The multiscale POD (mPOD) and EEMD are adopted to study the energy contributions regarding the cavitation-induced loading and thrust. The mPOD modes illuminate that the leading-edge loading oscillations of the obstacle blade are consequently eliminated where the cavitation is completely depressed and the obstacle cavitation wakes greatly contribute to loading excitation. The thrust statistics demonstrate that the thrust extremes and standard deviation in some revolutions can be well reduced as the large-scale leading-edge cavity depression. The adaptive spectrums obtained by EEMD further illuminate that both the tonal and broadband components of blade thrust would be reasonably degraded to some degree. The pump with only one obstacle implementation, as an improvement strategy, is comparatively studied and indicates that single obstacle configuration presents positive effects on the leading-edge cavity depression owing to the pressure-raising effects and can reduce the unnecessary energy loss compared with two obstacles.","PeriodicalId":54833,"journal":{"name":"Journal of Fluids Engineering-Transactions of the Asme","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135432118","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

Numerical Studies On the Oil Film Thickness in the Case of Stratified Flow with Different Oil-Water Flow Combinations Through Sudden Contraction Tube 突然收缩管中不同油水流组合分层流的油膜厚度数值研究

3区工程技术

Journal of Fluids Engineering-Transactions of the Asme Pub Date : 2023-11-07 DOI: 10.1115/1.4064007

Mushtaque Momin, Soham Mahindar, Faisal Rahmani, Mukesh Sharma

{"title":"Numerical Studies On the Oil Film Thickness in the Case of Stratified Flow with Different Oil-Water Flow Combinations Through Sudden Contraction Tube","authors":"Mushtaque Momin, Soham Mahindar, Faisal Rahmani, Mukesh Sharma","doi":"10.1115/1.4064007","DOIUrl":"https://doi.org/10.1115/1.4064007","url":null,"abstract":"Abstract Most of the oil transportation industries deal with liquid-liquid flow considering the adiabatic situation. In such applications, film thickness measurement plays a very significant role in understanding the flow characteristics. The distribution of phases for efficient wall treatment and to understand the phase distribution, measurement of film thickness is very important. Among different flow patterns, stratified flow is most common for low and medium viscous oil-water flow. At lower oil velocities, stratified flow is observed downstream of singularity whereas in the upstream section, stratified flow is observed for low to medium oil velocities and high-water superficial velocity. Variation of oil film thickness for stratified flow has been analyzed in the present study. Results show that oil film thickness decreases with the increase in the superficial velocity of water (Us-Water) for a constant oil superficial velocity (Us-Oil). With the increase in the volume fraction of one phase, the film thickness of that phase increases. As Us-Oil increases, the film thickness of oil also increases for a constant Us-Water. Oil film thickness is directly proportional to the viscosity of oils. This means, the more the viscosity of the oil, the more will be the oil film thickness.","PeriodicalId":54833,"journal":{"name":"Journal of Fluids Engineering-Transactions of the Asme","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135432994","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

Plume Spreading Due to Floor Conditions of A Plunging Liquid Jet Using Stereographic Backlit Imaging 利用立体背光成像研究俯冲液体射流地面条件下的羽流扩散

3区工程技术

Journal of Fluids Engineering-Transactions of the Asme Pub Date : 2023-11-07 DOI: 10.1115/1.4064004

Roy Pillers, Theodore J. Heindel

{"title":"Plume Spreading Due to Floor Conditions of A Plunging Liquid Jet Using Stereographic Backlit Imaging","authors":"Roy Pillers, Theodore J. Heindel","doi":"10.1115/1.4064004","DOIUrl":"https://doi.org/10.1115/1.4064004","url":null,"abstract":"Abstract Plunging liquid jets are a multiphase flow studied to understand how gas is entrained in a liquid and the resulting mixing capabilities. From existing literature, it has been hypothesized that rising bubbles play a noticeable role in the multiphase hydrodynamics of the plunging liquid jet bubble plume, and that separating the rising bubbles from the incoming liquid jet can result in a significant increase in the depth of the bubble plume. This study explores the effects of separating the incoming liquid jet from the rising bubble plume through floor interactions and compression effects due to a finite tank depth. This configuration is found in many natural and industrial systems, but not within published literature. Using existing theoretical models of infinite depth plunging liquid jet systems, which align reasonably well with captured baseline data, two models are developed for when floor interactions are present, one theoretical and one empirical. The models show a correlation between plume spread and floor interaction with the incoming plunging liquid jet bubble plume. Data acquired through stereographic backlit imaging over a range of flow rates show a reasonable agreement with the proposed models.","PeriodicalId":54833,"journal":{"name":"Journal of Fluids Engineering-Transactions of the Asme","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135474886","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

Unsteady Reynolds-Averaged Navier-Stokes Simulations Of A Ducted Wind Turbine 风管式风力机的非定常reynolds - average Navier-Stokes模拟

3区工程技术

Journal of Fluids Engineering-Transactions of the Asme Pub Date : 2023-11-03 DOI: 10.1115/1.4063615

Drew Safford, Junfeng Wang, Charles Liang, Kenneth Visser

{"title":"Unsteady Reynolds-Averaged Navier-Stokes Simulations Of A Ducted Wind Turbine","authors":"Drew Safford, Junfeng Wang, Charles Liang, Kenneth Visser","doi":"10.1115/1.4063615","DOIUrl":"https://doi.org/10.1115/1.4063615","url":null,"abstract":"Abstract An unsteady Reynolds-averaged Navier–Stokes model on body-fitted meshes in a commercial package (SimericsMP+) with a mismatched grid interface is used to study fluid dynamics around a ducted wind turbine. The model is validated by studying turbulent flow past a marine propeller. The nondimensional thrust and torque coefficients are compared against experimental data and results from a large eddy simulation model. Both coefficients are found to be within 3% of experimental results. Following this validation, the impact of different tip speed ratios on the ducted wind turbine's fluid dynamics is assessed. The optimal tip speed ratio is found to be the design value of 3.93 with a maximum power coefficient of 0.465 based on the duct exit area. The corresponding thrust coefficient is found to be 1.02 based on the rotor area. Lower tip speed ratios experience larger flow separation on the duct interior. Higher tip speed ratios decrease the size of the low-velocity region behind the hub. The ducted wind turbine's performance at design conditions is compared to an open rotor. The ducted wind turbine increases the power coefficient by 96% over the open rotor. The impact of hub size on the ducted wind turbine is also studied by simulating a smaller hub with 77% diameter. At the design tip speed ratio, the smaller hub has a power coefficient of 0.417. The maximum power coefficient is found to be 0.446 at a higher tip speed ratio of 4.5.","PeriodicalId":54833,"journal":{"name":"Journal of Fluids Engineering-Transactions of the Asme","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135775410","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 Numerical Study Of Cyclist-Cyclist Aerodynamic Interaction Towards Efficient Overtaking Strategy 面向高效超车策略的自行车-自行车空气动力学相互作用数值研究

3区工程技术

Journal of Fluids Engineering-Transactions of the Asme Pub Date : 2023-10-30 DOI: 10.1115/1.4063935

Sinforiano Cantos, Kwan Pui Mok, Peng Zhou, Hanbo Jiang, Xiaochen Mao, Siyang Zhong, Xin Zhang

{"title":"A Numerical Study Of Cyclist-Cyclist Aerodynamic Interaction Towards Efficient Overtaking Strategy","authors":"Sinforiano Cantos, Kwan Pui Mok, Peng Zhou, Hanbo Jiang, Xiaochen Mao, Siyang Zhong, Xin Zhang","doi":"10.1115/1.4063935","DOIUrl":"https://doi.org/10.1115/1.4063935","url":null,"abstract":"Abstract In cycling races, overtaking is a crucial maneuver that involves drafting behind and moving to the side of another cyclist. The flow interaction between the cyclists has a very significant impact on the aerodynamic performance. Previous experimental and numerical studies have shown the aerodynamic drag changes at certain relative positions between cyclists. This study aims at providing a comprehensive aerodynamic power contour along a complete overtaking path, detailing the power at different relative positions to develop efficient overtaking strategies. The aerodynamic results are obtained with numerical simulations, the accuracy of which is validated against wind tunnel experiments. Improved sampling and data-fitting approaches are employed to enhance previous findings. The results show that starting the overtaking maneuver closest to the leading cyclist and overtaking with a larger lateral separation is the most aerodynamically efficient strategy. These findings provide valuable insights into developing optimal overtaking strategies in competitive cycling races.","PeriodicalId":54833,"journal":{"name":"Journal of Fluids Engineering-Transactions of the Asme","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136103266","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

An Investigation On The Steady And Unsteady Wake Flow Regimes And Aerodynamic Characteristics Of The Trapezoidal Cylinders Using Immersed Boundary-Lattice Boltzmann Method 用浸入边界-晶格玻尔兹曼方法研究梯形圆柱体的定常和非定常尾流流型及气动特性

3区工程技术

Journal of Fluids Engineering-Transactions of the Asme Pub Date : 2023-10-30 DOI: 10.1115/1.4063933

Akash Bhunia, Prabir Sikdar, Sunil Manohar Dash

{"title":"An Investigation On The Steady And Unsteady Wake Flow Regimes And Aerodynamic Characteristics Of The Trapezoidal Cylinders Using Immersed Boundary-Lattice Boltzmann Method","authors":"Akash Bhunia, Prabir Sikdar, Sunil Manohar Dash","doi":"10.1115/1.4063933","DOIUrl":"https://doi.org/10.1115/1.4063933","url":null,"abstract":"Abstract In this study, the flow physics of the forward-facing (FF) and backward-facing (BF) trapezoidal cylinders (TC) subjected to two-dimensional, incompressible, and laminar flow is investigated using an in-house developed flexible forcing immersed boundary lattice Boltzmann solver [Dash et al. (2014)]. The Reynolds number (Re) is defined based on the cylinder's characteristic length D. For the steady and unsteady flow regimes, Re is varied in the ranges of 10-40 and 75-125, respectively. The TC's shape is varied by modifying its non-dimensional axial H/D and transverse Y/D length scales, between 0.5 to 2 and 0 to 1, respectively. Here, TC's horizontal central axis is always aligned along the incoming flow direction. It is observed that the flow separation points on the FF-TC and BF-TC are strongly influenced by the geometric (H/D and Y/D) and flow parameters (Re). Based on the boundary layer separation point, we have categorized the wake flow regimes behind the FF-TC and BF-TC into four types. In addition, the effect of the geometric and flow parameters on the drag coefficient (Cd), vortex shedding frequency, and steady and unsteady wake characteristics are thoroughly investigated here. Furthermore, by performing non-linear regression analysis, we have proposed a set of correlation equations for the Cd and Strouhal number (St), using which the aerodynamic characteristics of differently shaped TC can be derived in the considered Re range without performing rigorous numerical simulations or experiments.","PeriodicalId":54833,"journal":{"name":"Journal of Fluids Engineering-Transactions of the Asme","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136102691","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

Aerodynamics And Flowfield Of Dep Tiltwing During Transition With Deflected Trailing-Edge Flap 后缘偏转襟翼转捩时深倾翼的空气动力学与流场

3区工程技术

Journal of Fluids Engineering-Transactions of the Asme Pub Date : 2023-10-30 DOI: 10.1115/1.4063934

Timothy Lee, James Ni, Ge Lin

{"title":"Aerodynamics And Flowfield Of Dep Tiltwing During Transition With Deflected Trailing-Edge Flap","authors":"Timothy Lee, James Ni, Ge Lin","doi":"10.1115/1.4063934","DOIUrl":"https://doi.org/10.1115/1.4063934","url":null,"abstract":"Abstract The aerodynamics and flowfield of a rectangular semi-wing equipped with four four-bladed propellers and a 40%-chord full-span plain trailing-edge flap were investigated by using force balance and particle image velocimetry (PIV). The DEP (distributed electric propulsion) wing was tilted from zero to 90-deg angle of attack. The maximum lift coefficient, lift-curve slope, and stall angle of the DEP wing were found to increase significantly with increasing propeller rotation. The DEP wing also exhibited a gradual stall in contrast to the sudden stall of the baseline wing. The lift coefficient of the DEP wing positioned vertically at 90 deg was also found to be greatly increased with increasing propeller rotation. Regardless of the magnitude of propeller rotation, the general pattern and behavior of the lift curve was consistent. For the flapped DEP wing, the deployment of the flap led to a further increase in the maximum lift coefficient and lift-curve slope but an earlier wing stall and an increased drag as compared to the unflapped wing. The flap deflection also led to a lowered lift coefficient in the post-stall angle-of-attack regime as compared to the unflapped DEP wing. Gurney flap was also employed to further increase the lift generation of the DEP wing. The lift augmentation produced by the propeller slipstream was supplemented by the PIV flowfield measurements.","PeriodicalId":54833,"journal":{"name":"Journal of Fluids Engineering-Transactions of the Asme","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136104852","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