Volume 1: Flow Manipulation and Active Control; Bio-Inspired Fluid Mechanics; Boundary Layer and High-Speed Flows; Fluids Engineering Education; Transport Phenomena in Energy Conversion and Mixing; Turbulent Flows; Vortex Dynamics; DNS/LES and Hybrid RANS/LES Methods; Fluid Structure Interaction; Fl最新文献_第3页

Synthetic Jet Flow Control Optimization on SD7003 Airfoil at Low Reynolds Number SD7003低雷诺数翼型综合射流控制优化

Volume 1: Flow Manipulation and Active Control; Bio-Inspired Fluid Mechanics; Boundary Layer and High-Speed Flows; Fluids Engineering Education; Transport Phenomena in Energy Conversion and Mixing; Turbulent Flows; Vortex Dynamics; DNS/LES and Hybrid RANS/LES Methods; Fluid Structure Interaction; Fl Pub Date : 2018-07-15 DOI: 10.1115/FEDSM2018-83195

D. Kamari, M. Tadjfar

引用次数: 1

Numerical Comparison Between Steady and Sweeping Jets for Active Flow Control Applications 主动气流控制应用中稳态射流与扫掠射流的数值比较

Volume 1: Flow Manipulation and Active Control; Bio-Inspired Fluid Mechanics; Boundary Layer and High-Speed Flows; Fluids Engineering Education; Transport Phenomena in Energy Conversion and Mixing; Turbulent Flows; Vortex Dynamics; DNS/LES and Hybrid RANS/LES Methods; Fluid Structure Interaction; Fl Pub Date : 2018-07-15 DOI: 10.1115/FEDSM2018-83083

S. Aram, A. DeJong

{"title":"Numerical Comparison Between Steady and Sweeping Jets for Active Flow Control Applications","authors":"S. Aram, A. DeJong","doi":"10.1115/FEDSM2018-83083","DOIUrl":"https://doi.org/10.1115/FEDSM2018-83083","url":null,"abstract":"A computational study is conducted to compare the performance of an array of steady jets and sweeping jets (generated by fluidic oscillator) interacting with an attached turbulent cross flow. Both jets operate at the same supply rate and with the jet-to-freestream velocity ratio of three. Two array spacings are considered in this study; one is chosen based on the minimum possible distance between the adjacent fluidic oscillators, and the other spacing represents an actuator’s configuration with the least interaction between jets. The improved delayed detached eddy simulation model is employed as a high fidelity turbulence modeling approach to resolve accurately the flow structures. Formation of strong vortex pairs is observed in both actuation techniques with the opposite sense of rotation between them. As expected, the sweeping jet affects a wider region of incoming turbulent flow along the spanwise direction compared to the steady jet. Examining the turbulence properties of the flow downstream of the jets indicates that the sweeping jet is a better candidate for enhancing the mixing mechanism used to control separation. Comparing both the instantaneous and time-averaged flow fields generated by the sweeping jets and steady jets reveals that the interaction between the adjacent sweeping jets at the minimum spacing arrangement is significantly stronger than that of the steady jets.","PeriodicalId":23480,"journal":{"name":"Volume 1: Flow Manipulation and Active Control; Bio-Inspired Fluid Mechanics; Boundary Layer and High-Speed Flows; Fluids Engineering Education; Transport Phenomena in Energy Conversion and Mixing; Turbulent Flows; Vortex Dynamics; DNS/LES and Hybrid RANS/LES Methods; Fluid Structure Interaction; Fl","volume":"24 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78053994","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: 1

Experimental Investigation of a Flapping Motion Downstream of a Backward Facing Step 后向台阶下扑动的实验研究

Volume 1: Flow Manipulation and Active Control; Bio-Inspired Fluid Mechanics; Boundary Layer and High-Speed Flows; Fluids Engineering Education; Transport Phenomena in Energy Conversion and Mixing; Turbulent Flows; Vortex Dynamics; DNS/LES and Hybrid RANS/LES Methods; Fluid Structure Interaction; Fl Pub Date : 2018-07-15 DOI: 10.1115/FEDSM2018-83327

Zhuoyue Li, N. Gao

引用次数: 1

Analysis of Transient Two-Phase Flow in Pressure Safety Valve Outlet Headers 压力安全阀出口集管内瞬态两相流分析

Volume 1: Flow Manipulation and Active Control; Bio-Inspired Fluid Mechanics; Boundary Layer and High-Speed Flows; Fluids Engineering Education; Transport Phenomena in Energy Conversion and Mixing; Turbulent Flows; Vortex Dynamics; DNS/LES and Hybrid RANS/LES Methods; Fluid Structure Interaction; Fl Pub Date : 2018-07-15 DOI: 10.1115/FEDSM2018-83142

Maral Taghva, L. Damkilde

{"title":"Analysis of Transient Two-Phase Flow in Pressure Safety Valve Outlet Headers","authors":"Maral Taghva, L. Damkilde","doi":"10.1115/FEDSM2018-83142","DOIUrl":"https://doi.org/10.1115/FEDSM2018-83142","url":null,"abstract":"To protect a pressurized system from overpressure, one of the most established strategies is to install a Pressure Safety Valve (PSV). Therefore, the excess pressure of the system is relieved through a vent pipe when PSV opens. The vent pipe is also called “PSV Outlet Header”. After the process starts, a transient two-phase flow is formed inside the outlet header consisting of high speed pressurized gas interacting with existing static air. The high-speed jet compresses the static air towards the end tail of the pipe until it is discharged to the ambiance and eventually, the steady state is achieved. Here, this transient process is investigated both analytically and numerically using the method of characteristics. Riemann’s solvers and Godunov’s method are utilized to establish the solution. Propagation of shock waves and flow property alterations are clearly demonstrated throughout the simulations. The results show strong shock waves as well as high transient pressure take place inside the outlet header. This is particularly important since it indicates the significance of accounting for shock waves and transient pressure, in contrast to commonly accepted steady state calculations. More precisely, shock waves and transient pressure could lead to failure, if the pipe thickness is chosen only based on conventional steady state calculations.","PeriodicalId":23480,"journal":{"name":"Volume 1: Flow Manipulation and Active Control; Bio-Inspired Fluid Mechanics; Boundary Layer and High-Speed Flows; Fluids Engineering Education; Transport Phenomena in Energy Conversion and Mixing; Turbulent Flows; Vortex Dynamics; DNS/LES and Hybrid RANS/LES Methods; Fluid Structure Interaction; Fl","volume":"14 2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90396347","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

Mechanistic Modeling of Liquid Carry-Over for 3-Phase Flow in GLCC© Compact Separators GLCC©紧凑型分离器三相流液体携流机理建模

Volume 1: Flow Manipulation and Active Control; Bio-Inspired Fluid Mechanics; Boundary Layer and High-Speed Flows; Fluids Engineering Education; Transport Phenomena in Energy Conversion and Mixing; Turbulent Flows; Vortex Dynamics; DNS/LES and Hybrid RANS/LES Methods; Fluid Structure Interaction; Fl Pub Date : 2018-07-15 DOI: 10.1115/FEDSM2018-83407

S. Kolla, R. Mohan, O. Shoham

引用次数: 1

Wing Tip Vortex Development Under a Grid Generated Turbulent Flow 网格湍流下翼尖涡的发展

Volume 1: Flow Manipulation and Active Control; Bio-Inspired Fluid Mechanics; Boundary Layer and High-Speed Flows; Fluids Engineering Education; Transport Phenomena in Energy Conversion and Mixing; Turbulent Flows; Vortex Dynamics; DNS/LES and Hybrid RANS/LES Methods; Fluid Structure Interaction; Fl Pub Date : 2018-07-15 DOI: 10.1115/FEDSM2018-83478

Kamal Ben Miloud, Marouen Dghim, H. Fellouah, M. Ferchichi

{"title":"Wing Tip Vortex Development Under a Grid Generated Turbulent Flow","authors":"Kamal Ben Miloud, Marouen Dghim, H. Fellouah, M. Ferchichi","doi":"10.1115/FEDSM2018-83478","DOIUrl":"https://doi.org/10.1115/FEDSM2018-83478","url":null,"abstract":"The interaction of a NACA 0012 wingtip vortex with a grid-generated flow was investigated in this paper. The experiments were conducted in the near and mid-wakes regions at three free stream turbulence (FST) levels of 0.5% (empty wind tunnel), 3% and 6%, and at two Reynolds numbers, based on the wing chord length, of 2 × 105 and 3 × 105. Stereoscopic Particle Image Velocimetry (SPIV) and hot wire measurements were carried out at four downstream positions, namely x/c = 0.5, 2.5, 5 and 7. Streamwise velocity contours showed that the wingtip vortex decayed with increased FST and downstream distance. In the vortex core region, the streamwise velocity decelerated while the vortex adopted a wake-like profile. FST was found to decrease the vortex circulation, to increase the vortex radius, and to increase the vortex meandering amplitude. By increasing the Reynolds number, the grid cases showed a small variation of the vortex radius and vorticity peak, particularly at downstream positions of 5 and 7. With meandering correction, the turbulence level within the vortex core were found to be reduced as the artificial turbulence induced by the vortex meandering was removed.","PeriodicalId":23480,"journal":{"name":"Volume 1: Flow Manipulation and Active Control; Bio-Inspired Fluid Mechanics; Boundary Layer and High-Speed Flows; Fluids Engineering Education; Transport Phenomena in Energy Conversion and Mixing; Turbulent Flows; Vortex Dynamics; DNS/LES and Hybrid RANS/LES Methods; Fluid Structure Interaction; Fl","volume":"38 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91332746","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: 2

Optimization of Piece-Wise Conical Nozzles: Theory and Application 分段锥形喷嘴的优化:理论与应用

Volume 1: Flow Manipulation and Active Control; Bio-Inspired Fluid Mechanics; Boundary Layer and High-Speed Flows; Fluids Engineering Education; Transport Phenomena in Energy Conversion and Mixing; Turbulent Flows; Vortex Dynamics; DNS/LES and Hybrid RANS/LES Methods; Fluid Structure Interaction; Fl Pub Date : 2018-07-15 DOI: 10.1115/FEDSM2018-83055

K. Hasselmann, Muhammad Aiman Bin Khamalrudin, S. Wiesche, E. Kenig

{"title":"Optimization of Piece-Wise Conical Nozzles: Theory and Application","authors":"K. Hasselmann, Muhammad Aiman Bin Khamalrudin, S. Wiesche, E. Kenig","doi":"10.1115/FEDSM2018-83055","DOIUrl":"https://doi.org/10.1115/FEDSM2018-83055","url":null,"abstract":"In this contribution, an optimization study based on computational fluid dynamics (CFD) in combination with Stratford’s analytical separation criterion was developed for the design of piece-wise conical contraction zones. The occurrence of flow separation can be formally described by a newly introduced dimensionless separation number. In the optimization process, the risk of flow separation is reduced by minimizing this separation number. It was found that the optimized piece-wise conical nozzle shape did not correspond to a simple geometric approximation of the ideal polynomial shape. In fact, it was beneficial to reduce the deflection in the outlet region for a piece-wise conical nozzle stronger than for a conventional one. In order to validate the new design method, large-scale tests for different nozzle designs were conducted. The measured velocity profiles and wall pressure distributions agreed well with the CFD predictions. The new method was applied for designing the contraction zone of a new closed-loop organic vapor wind tunnel (CLOWT) working at elevated pressure levels.","PeriodicalId":23480,"journal":{"name":"Volume 1: Flow Manipulation and Active Control; Bio-Inspired Fluid Mechanics; Boundary Layer and High-Speed Flows; Fluids Engineering Education; Transport Phenomena in Energy Conversion and Mixing; Turbulent Flows; Vortex Dynamics; DNS/LES and Hybrid RANS/LES Methods; Fluid Structure Interaction; Fl","volume":"331 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76577790","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

Wake Flow Patterns Behind Rotating Smooth Spheres and Baseballs 旋转光滑球体和棒球背后的尾流模式

Volume 1: Flow Manipulation and Active Control; Bio-Inspired Fluid Mechanics; Boundary Layer and High-Speed Flows; Fluids Engineering Education; Transport Phenomena in Energy Conversion and Mixing; Turbulent Flows; Vortex Dynamics; DNS/LES and Hybrid RANS/LES Methods; Fluid Structure Interaction; Fl Pub Date : 2018-07-15 DOI: 10.1115/FEDSM2018-83357

P. Mortimer, J. Vaccaro, D. M. Rooney

{"title":"Wake Flow Patterns Behind Rotating Smooth Spheres and Baseballs","authors":"P. Mortimer, J. Vaccaro, D. M. Rooney","doi":"10.1115/FEDSM2018-83357","DOIUrl":"https://doi.org/10.1115/FEDSM2018-83357","url":null,"abstract":"An experimental investigation into the flow field behind baseballs at two different seam orientations as well as a smooth sphere of the same diameter was undertaken at Reynolds numbers of 5 × 104 and 1 × 105. The rotational speed of the three spheres varied from 0 to 2400 rpm, with data collected in increments of 400 rpm which correspond to relative spin rates between 0 and 0.94. Mean velocity profiles, turbulence in intensity profiles, and power spectral density of the signals were taken using hot-wire anemometry. The smooth sphere wake was seen to change in orientation over a range of relative rotational speeds. The Strouhal number remained constant around 0.24 for relatively low spin rates. The seams on the baseball suppressed any measurable vortex shedding once rotation began, also eliminating any significant change in wake orientation as evidenced by the mean velocity deficit and turbulence intensity profiles. It was concluded that the so-called inverse Magnus effect recorded by previous investigators at a specific Reynolds number / relative rotational speed of a sphere exists only for a smooth sphere and not for a sphere where the boundary layer separation is governed by raised seams.","PeriodicalId":23480,"journal":{"name":"Volume 1: Flow Manipulation and Active Control; Bio-Inspired Fluid Mechanics; Boundary Layer and High-Speed Flows; Fluids Engineering Education; Transport Phenomena in Energy Conversion and Mixing; Turbulent Flows; Vortex Dynamics; DNS/LES and Hybrid RANS/LES Methods; Fluid Structure Interaction; Fl","volume":"44 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79590079","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

Effects of Offset Height on the Turbulent Characteristics of Rectangular Twin Jets 偏置高度对矩形双射流湍流特性的影响

Volume 1: Flow Manipulation and Active Control; Bio-Inspired Fluid Mechanics; Boundary Layer and High-Speed Flows; Fluids Engineering Education; Transport Phenomena in Energy Conversion and Mixing; Turbulent Flows; Vortex Dynamics; DNS/LES and Hybrid RANS/LES Methods; Fluid Structure Interaction; Fl Pub Date : 2018-07-15 DOI: 10.1115/FEDSM2018-83264

C. F. Nwaiwu, M. Tachie, M. Agelin-Chaab

{"title":"Effects of Offset Height on the Turbulent Characteristics of Rectangular Twin Jets","authors":"C. F. Nwaiwu, M. Tachie, M. Agelin-Chaab","doi":"10.1115/FEDSM2018-83264","DOIUrl":"https://doi.org/10.1115/FEDSM2018-83264","url":null,"abstract":"Turbulent characteristics of a twin jet were experimentally investigated for offset heights, h = 1d and 3d where d is the nozzle diameter. The experiments were conducted using a pair of rectangular nozzles of an aspect ratio of 3, that is oriented in the minor plane and with a nozzle separation ratio of 2.3. The Reynolds number, based on jet exit velocity and nozzle diameter was maintained at 4622. The results show that confinement effect decreased the merging point of the jets by 30% but there is no significant effect on the combined points. Reduced confinement showed an 89% reduction in the acceleration of the mean streamwise surface velocity. Two-point streamwise velocity correlations were used to investigate the large-scale coherent structures. The results revealed enhanced streamwise stretching of the structures as the offset height ratio decreased. In the combined region, the structures are more inclined towards the free surface as the offset height ratio decreased.","PeriodicalId":23480,"journal":{"name":"Volume 1: Flow Manipulation and Active Control; Bio-Inspired Fluid Mechanics; Boundary Layer and High-Speed Flows; Fluids Engineering Education; Transport Phenomena in Energy Conversion and Mixing; Turbulent Flows; Vortex Dynamics; DNS/LES and Hybrid RANS/LES Methods; Fluid Structure Interaction; Fl","volume":"41 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79663724","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

Coherent Structures of Tornado-Like Vortices 类龙卷风涡旋的相干结构

Volume 1: Flow Manipulation and Active Control; Bio-Inspired Fluid Mechanics; Boundary Layer and High-Speed Flows; Fluids Engineering Education; Transport Phenomena in Energy Conversion and Mixing; Turbulent Flows; Vortex Dynamics; DNS/LES and Hybrid RANS/LES Methods; Fluid Structure Interaction; Fl Pub Date : 2018-07-15 DOI: 10.1115/FEDSM2018-83152

M. Karami, L. Carassale, H. Hangan, M. Refan

{"title":"Coherent Structures of Tornado-Like Vortices","authors":"M. Karami, L. Carassale, H. Hangan, M. Refan","doi":"10.1115/FEDSM2018-83152","DOIUrl":"https://doi.org/10.1115/FEDSM2018-83152","url":null,"abstract":"Tornado-like vortices have distinctive characteristics that make them significantly different from atmospheric boundary flows. These dynamic characteristics are highly turbulent and unsteady which make them very complex. In this paper, it is tried to identify these dominant patterns, known as coherent structures, out of tornado-like vortex. These vortices are experimentally simulated in a 1/11 scaled model of WindEEE Dome at Western University.\u0000 Coherent structures provide simplified but physical understanding of the flow. The classical method for extraction of coherent structures is proper orthogonal decomposition (POD) method. However, there are serious concerns about POD as it has orthogonality constraint. Thus, we applied another method called independent component analysis (ICA) which does not have orthogonality restrictions. This method helped us to identify non-physical POD modes and to provide a better physical description of the flow.","PeriodicalId":23480,"journal":{"name":"Volume 1: Flow Manipulation and Active Control; Bio-Inspired Fluid Mechanics; Boundary Layer and High-Speed Flows; Fluids Engineering Education; Transport Phenomena in Energy Conversion and Mixing; Turbulent Flows; Vortex Dynamics; DNS/LES and Hybrid RANS/LES Methods; Fluid Structure Interaction; Fl","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78959258","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: 4