Journal of Fluids Engineering-Transactions of the Asme最新文献_第5页

Effect of Compressibility on Velocity Profile and Friction Factor of Gaseous Laminar Flows in a Microtube 可压缩性对微管内气体层流速度分布和摩擦系数的影响

IF 2 3区工程技术

Journal of Fluids Engineering-Transactions of the Asme Pub Date : 2021-11-01 DOI: 10.1115/1.4051422

S. Murakami, Kaoru Toyoda, Y. Asako

{"title":"Effect of Compressibility on Velocity Profile and Friction Factor of Gaseous Laminar Flows in a Microtube","authors":"S. Murakami, Kaoru Toyoda, Y. Asako","doi":"10.1115/1.4051422","DOIUrl":"https://doi.org/10.1115/1.4051422","url":null,"abstract":"\u0000 Laminar flow of nitrogen gas in a microtube was simulated numerically to obtain velocity profile and Fanning friction factor in a quasi-fully developed region. The numerical procedure based on Arbitrary-Lagrangian-Eulerian method solved two-dimensional compressible momentum and energy equations. The computations were performed for a wide range of Reynolds number in laminar flow regime with adiabatic wall condition. It was found that the velocity profile deviates from the parabola as Mach number increases, and the product of Fanning friction factor and Reynolds number is not a constant but a function of only Mach number. To explain the compressibility effect, a new theoretical flow model which gives the velocity profile of gaseous laminar flows in a microtube was proposed under the assumption of purely axial flow. The theoretical velocity profile is taking radial-direction density change into account, and coincides with the numerically obtained velocity profile. The proposed flow model also shows that the Fanning friction factor of a compressible flow in a microtube is expressed by a quadratic function of Mach number. The coefficient of the Mach squared term is 40% of the numerically obtained correlation. The compressibility effect on friction factor of gaseous laminar flows in a microtube partly results from velocity profile change which must occur to keep the mass velocity profile when density changes in radial direction. The remainder of the compressibility effect can be considered to result from actual mass transfer in the radial direction whose existence was demonstrated by the numerical results.","PeriodicalId":54833,"journal":{"name":"Journal of Fluids Engineering-Transactions of the Asme","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2021-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84009898","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

Thermodynamic Effects on Pressure Fluctuations of a Liquid Oxygen Turbopump 液氧涡轮泵压力波动的热力学影响

IF 2 3区工程技术

Journal of Fluids Engineering-Transactions of the Asme Pub Date : 2021-11-01 DOI: 10.1115/1.4051218

Deyou Li, Zhipeng Ren, Yu Li, Boxuan Miao, R. Gong, Hongjie Wang

{"title":"Thermodynamic Effects on Pressure Fluctuations of a Liquid Oxygen Turbopump","authors":"Deyou Li, Zhipeng Ren, Yu Li, Boxuan Miao, R. Gong, Hongjie Wang","doi":"10.1115/1.4051218","DOIUrl":"https://doi.org/10.1115/1.4051218","url":null,"abstract":"\u0000 Liquid oxygen turbopumps are an important component of rocket engines. The instability induced by cavitation flow in turbopumps has received considerable attention because of thermodynamic effects. In this study, unsteady numerical simulations of a turbopump with thermodynamic effects were performed. The frequency composition and source of pressure fluctuations in a turbopump were analyzed, and the difference in pressure fluctuations with/without thermodynamic effects was revealed. The results showed that the pressure fluctuations were mainly caused by the interaction between the impeller and diffuser, and the thermodynamic effects slightly increased the amplitudes of the characteristic frequencies. In addition, in the inducer and impeller, three characteristic frequencies (4.089fn, 2.519fn, and 3.238fn, where fn is the rotational frequency) were confirmed. Analyses revealed that the 4.089fn was due to the periodic shedding of cavitation structures on the suction surfaces at the inducer outlet, 2.519fn was induced by the periodic occurrence and collapse of cavitation on the suction surfaces at the impeller inlet; and 3.238fn was from the periodic shedding of cavitation structures on the suction surfaces at the impeller middle blades. The existence of thermodynamic effects decreased the frequency of cavitation shedding and increased the frequency of the periodic occurrence and collapse of cavitation.","PeriodicalId":54833,"journal":{"name":"Journal of Fluids Engineering-Transactions of the Asme","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2021-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74054170","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: 11

Analysis of Gas-Liquid-Solid Three-Phase Flows in Hydrocyclones Through a Coupled Method of VOF and DEM 利用VOF和DEM耦合方法分析旋流器内气-液-固三相流动

IF 2 3区工程技术

Journal of Fluids Engineering-Transactions of the Asme Pub Date : 2021-11-01 DOI: 10.1115/1.4051219

Jiachuan Yu, Xiaotong Luo, Bo Wang, Song-hai Wu, Jingtao Wang

{"title":"Analysis of Gas-Liquid-Solid Three-Phase Flows in Hydrocyclones Through a Coupled Method of VOF and DEM","authors":"Jiachuan Yu, Xiaotong Luo, Bo Wang, Song-hai Wu, Jingtao Wang","doi":"10.1115/1.4051219","DOIUrl":"https://doi.org/10.1115/1.4051219","url":null,"abstract":"\u0000 Liquid-gas-solid three-phase flows in hydrocyclones are studied numerically in this paper by employing a coupled method of volume of fluid (VOF) and discrete element model (DEM) with RSM turbulence model. The numerical method is validated by comparing the calculated results to those of experiments published in literature about the separation of particle flows in hydrocyclones. Since VOF-DEM model could capture the gas-liquid interface of particle flows, the three-dimensional formation process of the air-core together with the formation of the spiral trajectory of particles are depicted for the first time. In addition, the effects of the particle concentration ? (less than 12%) on the air-core formation time Tf and diameter Da are studied systematically, which has not been reported in literature. The increase of ? has both positive and negative actions on the change of Tf and Da, and compromises of two kinds of actions generate the valley or peak of curves of Tf vs ? and Da vs ?, respectively. Moreover, the results for three hydrocyclones with different cone angles are also compared to study the effects of the cylindrical and conical section on the air-core formation and the separation performance of the hydrocyclones. By analyzing the flow fields and the pressure changes inside the hydrocyclones, qualitative explanations of the relevant discoveries are given in this paper. The results will be helpful in the investigation of the multiphase flow behaviors in the hydrocyclone and in the selection of the appropriate hydrocyclone.","PeriodicalId":54833,"journal":{"name":"Journal of Fluids Engineering-Transactions of the Asme","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2021-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91036161","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: 5

Air-Water Flow Properties in Hydraulic Jumps With Fully and Partially Developed Inflow Conditions 完全和部分发展入流条件下液压跃变中的空气-水流动特性

IF 2 3区工程技术

Journal of Fluids Engineering-Transactions of the Asme Pub Date : 2021-10-01 DOI: 10.1115/1.4051199

L. Montano, S. Felder

{"title":"Air-Water Flow Properties in Hydraulic Jumps With Fully and Partially Developed Inflow Conditions","authors":"L. Montano, S. Felder","doi":"10.1115/1.4051199","DOIUrl":"https://doi.org/10.1115/1.4051199","url":null,"abstract":"\u0000 Novel air–water flow measurements were conducted in fully aerated hydraulic jumps with partially and fully developed supercritical inflow conditions. Irrespective of the inflow conditions, the hydraulic jumps resembled typical flow patterns with strong aeration and instabilities, albeit hydraulic jumps with fully developed inflow conditions had a more upward directed roller motion and a larger clear water core in the second half of the roller. Hydraulic jumps with fully developed inflow conditions had comparatively larger void fractions in the first half of the jump roller and larger bubble count rates throughout, while a comparatively larger number of smaller bubble sizes suggested a stronger break-up of bubbles. This was consistent with slightly larger interfacial velocities and turbulence intensities in the first half of the jump roller with fully developed inflow conditions. An assessment of the required sampling duration for air–water flow properties indicated the requirement to sample for at least five times longer than applied in previous studies. These results highlighted the need to carefully consider the inflow conditions and sampling parameters for aerated hydraulic jumps.","PeriodicalId":54833,"journal":{"name":"Journal of Fluids Engineering-Transactions of the Asme","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2021-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88187899","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: 9

Generation of Twin Vortex Rope in the Draft-Tube Elbow of a Francis Turbine During Deep Part-Load Operation 混流式水轮机尾水管弯头深部分负荷运行时双涡绳的产生

IF 2 3区工程技术

Journal of Fluids Engineering-Transactions of the Asme Pub Date : 2021-10-01 DOI: 10.1115/1.4051150

M. H. Khozaei, A. Favrel, T. Masuko, N. Yamaguchi, K. Miyagawa

引用次数: 8

Flow of Power-Law Fluids Past a Rotating Cylinder at High Reynolds Numbers 幂律流体在高雷诺数下流过旋转圆柱体的流动

IF 2 3区工程技术

Journal of Fluids Engineering-Transactions of the Asme Pub Date : 2021-10-01 DOI: 10.1115/1.4050973

P. Thakur, Naveen Tiwari, R. Chhabra

{"title":"Flow of Power-Law Fluids Past a Rotating Cylinder at High Reynolds Numbers","authors":"P. Thakur, Naveen Tiwari, R. Chhabra","doi":"10.1115/1.4050973","DOIUrl":"https://doi.org/10.1115/1.4050973","url":null,"abstract":"\u0000 In this study, a rotating cylinder is placed in a stream of shear-thinning fluids, flowing with a uniform velocity. Detailed investigations are performed for the following range of conditions: Reynolds number 100≤Re≤500, power-law index 0.2≤n≤1 and rotational velocity 0≤α≤5. Flow transitions are observed from steady to unsteady at critical values of the Reynolds number, the rotational velocity, and the power-law index. Critical values of the Reynolds number Rec have been obtained for varying levels of the rotational velocity, and the power-law index. Rec varies nonmonotonically with the rotational velocity. At a particular Reynolds number, an increase of the rotational velocity acts as a vortex suppression technique. For shear-thinning fluids considered here, the vortex suppression occurs at a larger value of the critical rotational velocity αc, relative to Newtonian fluids. For the unsteady flow, the lift coefficient versus time curve exhibits oscillatory behavior, and this has been used to delineate the flow regime as steady or unsteady flow. For unsteady flow regimes, both the amplitude of the lift coefficient and the Strouhal number increase with increasing Reynolds numbers. The results presented in this work for such high Reynolds numbers elucidate the possible complex interplay between the kinematic and rheological parameters of non-Newtonian fluids. This investigation also complements the currently available low Reynolds number results up to ∼ Re=140.","PeriodicalId":54833,"journal":{"name":"Journal of Fluids Engineering-Transactions of the Asme","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2021-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80091057","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

On the Motion of Single and Twin Oblique Particle Clouds in Stagnant Water 单斜粒子云和双斜粒子云在死水中的运动

IF 2 3区工程技术

Journal of Fluids Engineering-Transactions of the Asme Pub Date : 2021-10-01 DOI: 10.1115/1.4051149

Mahsa Janati, A. Azimi

引用次数: 1

Fluid Dynamics and Pressure Drop Prediction of Two-Phase Flow Through Sudden Contractions 突然收缩两相流的流体动力学和压降预测

IF 2 3区工程技术

Journal of Fluids Engineering-Transactions of the Asme Pub Date : 2021-09-01 DOI: 10.1115/1.4050962

S. Patra, M. K. Roul, P. Satapathy, A. Barik

{"title":"Fluid Dynamics and Pressure Drop Prediction of Two-Phase Flow Through Sudden Contractions","authors":"S. Patra, M. K. Roul, P. Satapathy, A. Barik","doi":"10.1115/1.4050962","DOIUrl":"https://doi.org/10.1115/1.4050962","url":null,"abstract":"\u0000 The aim of the present study is to investigate fluid dynamics and pressure drop across sudden contractions in a two-dimensional, axisymmetric pipe carrying a two-phase mixture of air (secondary phase) and water (primary phase), using the Eulerian–Eulerian model of the multiphase flow physics to solve the mass, momentum, volume fraction and turbulent quantities with relevant boundary conditions in a finite volume framework. The realizable per-phase k-ε and Reynolds stress models have been used as the closure for turbulent quantities along with enhanced wall function for the near-wall treatment. The effects of various parameters such as mass flux, mass flow quality, area ratio (0.056–0.619), flow directions (horizontal/vertical), and system pressure on the two-phase pressure drops due to a contraction in the pipe have been quantified. For both the single and two-phase flows, it has been observed that the pressure drop decreases with area ratio, and increases with mass flux and mass flow quality of two-phase flow. The vena contracta for a single-phase flow was found. But for two-phase flow, neither the vena contracta nor the recirculation zone has been observed, as the mass quality exceeds above 50%. A higher pressure drop has been observed for vertical pipes as compared to horizontal pipes. The present numerical results have also been validated with published experimental results, believed to be one of the alternatives to the costly experimental methods for predicting the flow dynamics and pressure drop.","PeriodicalId":54833,"journal":{"name":"Journal of Fluids Engineering-Transactions of the Asme","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78816103","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

Investigation of Flow Structure in a Narrow Clearance of a Low Specific Speed Centrifugal Impeller 低比转速离心叶轮窄间隙内流动结构研究

IF 2 3区工程技术

Journal of Fluids Engineering-Transactions of the Asme Pub Date : 2021-08-23 DOI: 10.1115/1.4052240

Yumeno Inaba, Kento Sakai, K. Miyagawa, M. Iino, T. Sano

引用次数: 0

Effects of Plate Edge Thickness On Droplet Generation Caused by Water Film Breakup At the Plate Edge 平板边缘厚度对平板边缘水膜破裂产生液滴的影响

IF 2 3区工程技术

Journal of Fluids Engineering-Transactions of the Asme Pub Date : 2021-08-12 DOI: 10.1115/1.4052126

D. Ito, Susumu Nakano, Yuriko Matsuzaki, Y. Takeda

引用次数: 0