Journal of Fluids Engineering-Transactions of the Asme最新文献_第7页

Hemodynamic Study of Blood Flow in the Carotid Artery with a Focus on Carotid Sinus Using Fluid-Structure Interaction 颈动脉血流动力学研究——以颈动脉窦血流为重点

IF 2 3区工程技术

Journal of Fluids Engineering-Transactions of the Asme Pub Date : 2021-07-27 DOI: 10.1115/1.4051902

Aditya Bantwal, A. Singh, A. Menon, Nitesh Kumar

引用次数: 4

3D Flow Simulation of a Twin-Screw Pump for the Analysis of Gap Flow Characteristics 基于间隙流特性分析的双螺杆泵三维流动仿真

IF 2 3区工程技术

Journal of Fluids Engineering-Transactions of the Asme Pub Date : 2021-07-12 DOI: 10.1115/1.4051730

Ali Hassannejadmoghaddam, B. Kutschelis, F. Holz, Tomas Börjesson, R. Skoda

引用次数: 2

Effect of Rear Wing on Time-Averaged Ground Vehicle Wake With Variable Slant Angle 尾翼对变倾角时平均地面车辆尾迹的影响

IF 2 3区工程技术

Journal of Fluids Engineering-Transactions of the Asme Pub Date : 2021-07-01 DOI: 10.1115/1.4050373

S. Uddin, F. Rashid

{"title":"Effect of Rear Wing on Time-Averaged Ground Vehicle Wake With Variable Slant Angle","authors":"S. Uddin, F. Rashid","doi":"10.1115/1.4050373","DOIUrl":"https://doi.org/10.1115/1.4050373","url":null,"abstract":"\u0000 The slant angle plays a crucial role in the flow property of hatchback ground vehicles. An optimum slant angle is obligatory for better handling the ground vehicles when fitted with a rear wing. In this regard, the variation of time-averaged flow properties around a wing-attached hatchback ground vehicle (Ahmed body) due to a variable slant angle is accessed by this paper. The design includes a scaled Ahmed body as a reference ground vehicle and a rear wing with NACA 0018 profile. The computational studies are executed with Reynolds-averaged Navier–Stokes based k-epsilon turbulence model with nonequilibrium wall function. The vehicle's model is scaled to 75% of the actual model, and analyses are conducted with Reynolds number 2.7 × 106. After the study, it is observed that a 15 deg slant angle is the critical angle for the wing attached state in which the drag coefficient is maximum. After this angle, a sudden reduction of coefficients is observed, where 25 deg is critical for without wing condition. Besides this, the two counter-rotating horseshoe vortices in the separation bubble and side edge c-pillar vortices also behave differently due to the wing's presence. The turbulent kinetic energy variation and the variation in coefficients of surface pressure are also affected by the rear wing attachment. This paper will assist in finding the optimum slant angle for hatchback ground vehicles in the presence of a rear wing. Thus the study will help in increasing stability and control for hatchback ground vehicles.","PeriodicalId":54833,"journal":{"name":"Journal of Fluids Engineering-Transactions of the Asme","volume":"36 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2021-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82477223","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

Control of Mass Flow-Rate of Viscoelastic Fluids Through Time-Periodic Electro-Osmotic Flows in a Microchannel 微通道中时间周期电渗透流对粘弹性流体质量流量的控制

IF 2 3区工程技术

Journal of Fluids Engineering-Transactions of the Asme Pub Date : 2021-06-15 DOI: 10.1115/1.4051429

Sayantan Dawn, S. Sarkar

{"title":"Control of Mass Flow-Rate of Viscoelastic Fluids Through Time-Periodic Electro-Osmotic Flows in a Microchannel","authors":"Sayantan Dawn, S. Sarkar","doi":"10.1115/1.4051429","DOIUrl":"https://doi.org/10.1115/1.4051429","url":null,"abstract":"\u0000 In the present research, we address the implications of the pulsating electric field on controlling mass flow-rate characteristics for the time-periodic electro-osmotic flow of a viscoelastic fluid through a microchannel. Going beyond the Debye-Hückel linearization for the potential distribution inside the Electric Double Layer, the Phan-Thien-Tanner constitutive model is employed to describe the viscoelastic behaviour of the fluid. The analytical/semi-analytical expressions for the velocity distribution corresponding to a steady basic part, and a transient perturbed part are obtained by considering periodic pulsations in the applied electrical field. Our results based on sinusoidal pulsations reveal that enhanced shear thinning characteristics of the viscoelastic fluids show higher amplitude of pulsations with the oscillations in the velocity gradients primarily contrived within the Electric Double Layer region. The amplitude of mass flow rates increases with increasing the viscoelastic parameter , whereas, the phase lag displays a reverse trend. The analysis for an inverse problem is extended where the required magnitude of electric field pulsations for a target mass flow rate in the form of sinusoidal pulsations. It is found that with increasing shear-thinning characteristics of the viscoelastic fluid, there is a progressive reduction in the required electric field strength to maintain an aimed mass flow rate. Besides, required electric fields for controlled mass flow with triangular and trapezoidal pulsations are also determined.","PeriodicalId":54833,"journal":{"name":"Journal of Fluids Engineering-Transactions of the Asme","volume":"1 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2021-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89562657","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: 2

Suction and Injection Impacts on Casson Nanofluid With Gyrotactic Micro-organisms Over a Moving Wedge 旋转微生物在移动楔上吸注对卡森纳米流体的影响

IF 2 3区工程技术

Journal of Fluids Engineering-Transactions of the Asme Pub Date : 2021-06-15 DOI: 10.1115/1.4051484

K. Jabeen, M. Mushtaq, R. Akram

{"title":"Suction and Injection Impacts on Casson Nanofluid With Gyrotactic Micro-organisms Over a Moving Wedge","authors":"K. Jabeen, M. Mushtaq, R. Akram","doi":"10.1115/1.4051484","DOIUrl":"https://doi.org/10.1115/1.4051484","url":null,"abstract":"\u0000 This work deals with the effects of suction and injection on Casson nanofluid around a moving wedge under the influence of gyrotactic micro-organisms along with viscous and ohmic dissipation. The governing system of highly coupled nonlinear partial differential equations together with assisting boundary conditions is converted by applying suitable similarity transformations, into a set of nonlinear ordinary differential equations. The obtained flow model is solved numerically by bvp4c (matlab) procedure. The accuracy of the flow model under consideration is validated by employing another well-known mathematical technique Runge–Kutta-Fehlberg (RKF) having good agreement while comparing the numerical results obtained by bvp4c for both suction and injection cases. Impacts of various pertinent parameters active in the flow model such as thermophoresis and Brownian motion, moving wedge, magnetic field, viscous and ohmic dissipation are numerically calculated for both suction and injection flow situations and also presented graphically. It is observed that the increase in casson parameter enhances the velocity but declines the density of motile organism, concentration and temperature for suction as well as injection flow case. The impacts of mass transfer rate of gyrotactic micro-organisms, Nusselt and Sherwood numbers for various fluid parameters are numerically presented in tabular form, separately for both suction and injection. One of the important observations of this study is that the suction or injection plays a key role in controlling boundary layer flow and brings stability in the flow. Moreover, rate of heat and mass transfer get enhanced in the existence of gyrotactic micro-organisms. Further, it would be worth mentioning that physical behavior of this flow problem coincides very well with already published literature either graphically or in tabular representation.","PeriodicalId":54833,"journal":{"name":"Journal of Fluids Engineering-Transactions of the Asme","volume":"69 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2021-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74120211","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: 14

Evaluation of Length Scales and Meshing Requirements for Resolving Two-Phase Flow Regime Transitions Using the Level Set Method 用水平集法求解两相流流型转换的长度尺度和网格要求评价

IF 2 3区工程技术

Journal of Fluids Engineering-Transactions of the Asme Pub Date : 2021-06-01 DOI: 10.1115/1.4049934

M. Zimmer, I. Bolotnov

{"title":"Evaluation of Length Scales and Meshing Requirements for Resolving Two-Phase Flow Regime Transitions Using the Level Set Method","authors":"M. Zimmer, I. Bolotnov","doi":"10.1115/1.4049934","DOIUrl":"https://doi.org/10.1115/1.4049934","url":null,"abstract":"\u0000 New criteria for fully resolving two-phase flow regime transitions using direct numerical simulation with the level set method for interface capturing are proposed. A series of flows chosen to capture small scale interface phenomena are simulated at different grid refinements. These cases include droplet deformation and breakup in a simple shear field, the thin film around a Taylor bubble, and the rise of a bubble toward a free surface. These cases cover the major small scale phenomena observed in two-phase flows: internal recirculation, interface curvature, interface snapping, flow of liquid in thin films, and drainage/snapping of thin films. The results from these simulations and their associated grid studies were used to develop new meshing requirements for simulation of two-phase flow using interface capturing methods, in particular the level set method. When applicable, the code used in this work, PHASTA, was compared to experiments in order to contribute to the ongoing validation process of the code. Results show that when the solver meets these criteria, with the exception of resolving the nanometer scale liquid film between coalescing bubbles, the code is capable of accurately simulating interface topology changes.","PeriodicalId":54833,"journal":{"name":"Journal of Fluids Engineering-Transactions of the Asme","volume":"39 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80639858","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: 2

Investigation of the Matching Relation Between Impeller and Flow Channel of Regenerative Flow Pumps 蓄热式流泵叶轮与流道匹配关系的研究

IF 2 3区工程技术

Journal of Fluids Engineering-Transactions of the Asme Pub Date : 2021-06-01 DOI: 10.1115/1.4050009

Qian-qian Li, Cheng-shuo Wu, B. Qian, Peng Wu, Bin Huang, Dazhuan Wu

{"title":"Investigation of the Matching Relation Between Impeller and Flow Channel of Regenerative Flow Pumps","authors":"Qian-qian Li, Cheng-shuo Wu, B. Qian, Peng Wu, Bin Huang, Dazhuan Wu","doi":"10.1115/1.4050009","DOIUrl":"https://doi.org/10.1115/1.4050009","url":null,"abstract":"\u0000 As a specific radial flow pump, the regenerative flow pump (RFP) usually has a low efficiency. In this study, in order to explore the matching mechanism, three cases with various matching relations were investigated by the methods of theoretical calculation, computational fluids dynamics (CFD) simulation, and experiment test. The results illustrate that the theoretical prediction, numerical simulation, and experimental data are in good agreement. Furthermore, when the matching relation expressed by a ratio of the channel's and blade's radial length is equal to 1, the geometrical profiles of RFP can well guide the circulation flow into the channel at large radii and into the impeller at small radii, forming intense longitudinal vortex. The steady, strong exchange flow is characterized by the inflow and outflow regions approximately half of the isosurface. The axial vortex motion without apparent flow separation and irregular flow is observed in the impeller, a low velocity annulus exists in the medium radii of the impeller without other distinct velocity clouds, and a low velocity strip and a high velocity annulus in the channel are, respectively, performed along the blade's pressure surface and the channel's outer radii. All of this corresponds to the best pump's performance and the largest efficiency of the impeller and channel. This work promotes a systematical understanding of the matching mechanism between impeller and flow channel in the RFP and could provide some reference for the design and performance optimization for RFP.","PeriodicalId":54833,"journal":{"name":"Journal of Fluids Engineering-Transactions of the Asme","volume":"60 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80987877","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

Influence of Blade Tip Surface Roughness on the Performance of a Single-Stage Axial Flow Compressor 叶尖表面粗糙度对单级轴流压气机性能的影响

IF 2 3区工程技术

Journal of Fluids Engineering-Transactions of the Asme Pub Date : 2021-06-01 DOI: 10.1115/1.4049935

Pradyumna Kodancha, P. Salunkhe

引用次数: 1

Influence of Tip Clearance on the Hydrodynamic Damping Characteristics of a Hydrofoil 叶尖间隙对水翼水动力阻尼特性的影响

IF 2 3区工程技术

Journal of Fluids Engineering-Transactions of the Asme Pub Date : 2021-06-01 DOI: 10.1115/1.4049675

Zeng Yongshun, Z. Yao, Zhang Shijie, Fujun Wang, R. Xiao

{"title":"Influence of Tip Clearance on the Hydrodynamic Damping Characteristics of a Hydrofoil","authors":"Zeng Yongshun, Z. Yao, Zhang Shijie, Fujun Wang, R. Xiao","doi":"10.1115/1.4049675","DOIUrl":"https://doi.org/10.1115/1.4049675","url":null,"abstract":"Tip clearance in hydraulic machines may complicate the fluid–structure interaction (FSI) effects. In this investigation, a mode-based approach (modal work) is evaluated and employed to quantitatively predict the added mass, added stiffness, and hydrodynamic damping ratio, in relation to the first-order bending mode of a vibrating hydrofoil. The investigated relative tip clearance ranges from 0.067% to 2% of the span length. The predicted vortex shedding frequency, natural frequency, and hydrodynamic damping ratio of the hydrofoil are in good agreement with the previously published experimental results, with relative deviations within 9.92%, 6.97%, and 11.23%, respectively. Simulation results show that the added mass, added stiffness, and hydrodynamic damping ratio increase inversely as the tip clearance increases. In particular, as the relative tip clearance increases from 0.067% to 2%, the added mass in still water, the added stiffness, and hydrodynamic damping ratio at a velocity of 10 m/s decrease by 18.66%, 9.36%, and 27.99%, respectively. As the tip clearance increases, the inversely increased pressure difference between the upper and lower surfaces of the vibrating hydrofoil is the main reason for the inversely increased hydrodynamic damping ratio. This is due to the energy leakages via the tip clearance region increase as the tip clearance increases, which may cause less fluid force to resist the vibration of the hydrofoil, resulting in less negative modal work done by the fluid load on the hydrofoil.","PeriodicalId":54833,"journal":{"name":"Journal of Fluids Engineering-Transactions of the Asme","volume":"27 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79817864","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: 7

Unsteady Hemodynamics in Intracranial Aneurysms With Varying Dome Orientations 颅内不同圆顶动脉瘤的不稳定血流动力学

IF 2 3区工程技术

Journal of Fluids Engineering-Transactions of the Asme Pub Date : 2021-06-01 DOI: 10.1115/1.4049932

A. Usmani, K. Muralidhar

{"title":"Unsteady Hemodynamics in Intracranial Aneurysms With Varying Dome Orientations","authors":"A. Usmani, K. Muralidhar","doi":"10.1115/1.4049932","DOIUrl":"https://doi.org/10.1115/1.4049932","url":null,"abstract":"\u0000 Fluid loading within an intracranial aneurysm is difficult to measure but can be related to the shape of the flow passage. The outcome of excessive loading is a fatal hemorrhage, making it necessary for early diagnosis. However, arterial diseases are asymptomatic and clinical assessment is a challenge. A realistic approach to examining the severity of wall loading is from the morphology of the aneurysm itself. Accordingly, this study compares pulsatile flow (Reynolds number Re = 426, Womersley number Wo = 4.7) in three different intracranial aneurysm geometries. Specifically, the spatio-temporal movement of vortices is followed in high aspect ratio aneurysm models whose domes are inclined along with angles of 0, 45, and 90 deg relative to the plane of the parent artery. The study is based on finite volume simulation of unsteady three-dimensional flow while a limited set of particle image velocimetry experiments have been carried out. Within a pulsatile cycle, an increase in inclination (0–90 deg) is seen to shift the point of impingement from the distal end toward the aneurysmal apex. This change in flow pattern strengthens helicity, drifts vortex cores, enhances spatial displacement of the vortex, and generates skewed Dean's vortices on transverse planes. Patches of wall shear stress and wall pressure shift spatially from the distal end in models of low inclination (0–45 deg) and circumscribe the aneurysmal wall for an inclination angle of 90 deg. Accordingly, it is concluded that high angles of inclination increase rupture risks while lower inclinations are comparatively safe.","PeriodicalId":54833,"journal":{"name":"Journal of Fluids Engineering-Transactions of the Asme","volume":"79 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76932379","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: 3