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Publisher: Springer-Verlag   (Total: 2340 journals)

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Showing 1201 - 1400 of 2340 Journals sorted alphabetically
J. of Combinatorial Optimization     Hybrid Journal   (Followers: 5, SJR: 1.093, h-index: 34)
J. of Communications Technology and Electronics     Hybrid Journal   (Followers: 2, SJR: 0.29, h-index: 16)
J. of Community Genetics     Hybrid Journal   (Followers: 1, SJR: 0.727, h-index: 14)
J. of Community Health     Hybrid Journal   (Followers: 8, SJR: 0.921, h-index: 44)
J. of Comparative Physiology A: Neuroethology, Sensory, Neural, and Behavioral Physiology     Hybrid Journal   (Followers: 8, SJR: 1.087, h-index: 74)
J. of Comparative Physiology B : Biochemical, Systemic, and Environmental Physiology     Hybrid Journal   (Followers: 4, SJR: 1.126, h-index: 59)
J. of Compassionate Health Care     Open Access   (Followers: 2)
J. of Computational Analysis and Applications     Hybrid Journal   (SJR: 0.291, h-index: 19)
J. of Computational Electronics     Hybrid Journal   (Followers: 4, SJR: 0.511, h-index: 20)
J. of Computational Neuroscience     Hybrid Journal   (Followers: 24, SJR: 1.068, h-index: 60)
J. of Computer and Systems Sciences Intl.     Hybrid Journal   (SJR: 0.27, h-index: 13)
J. of Computer Science and Technology     Open Access   (Followers: 5, SJR: 0.437, h-index: 31)
J. of Computer Virology and Hacking Techniques     Hybrid Journal   (Followers: 6, SJR: 0.151, h-index: 2)
J. of Computer-Aided Molecular Design     Hybrid Journal   (Followers: 2, SJR: 0.995, h-index: 78)
J. of Computers in Education     Hybrid Journal   (Followers: 8)
J. of Computing in Higher Education     Hybrid Journal   (Followers: 13, SJR: 0.363, h-index: 21)
J. of Consumer Policy     Hybrid Journal   (Followers: 7, SJR: 0.704, h-index: 30)
J. of Contemporary Mathematical Analysis     Hybrid Journal   (SJR: 0.237, h-index: 5)
J. of Contemporary Physics (Armenian Academy of Sciences)     Hybrid Journal   (Followers: 11, SJR: 0.197, h-index: 6)
J. of Contemporary Psychotherapy     Hybrid Journal   (Followers: 5, SJR: 0.397, h-index: 23)
J. of Control Theory and Applications     Hybrid Journal   (Followers: 2, SJR: 0.359, h-index: 19)
J. of Control, Automation and Electrical Systems     Hybrid Journal   (Followers: 10, SJR: 0.231, h-index: 9)
J. of Crop Science and Biotechnology     Hybrid Journal   (Followers: 7)
J. of Cross-Cultural Gerontology     Hybrid Journal   (Followers: 5, SJR: 0.631, h-index: 29)
J. of Cryptographic Engineering     Partially Free   (Followers: 5, SJR: 0.989, h-index: 11)
J. of Cryptology     Hybrid Journal   (Followers: 2, SJR: 1.443, h-index: 55)
J. of Cultural Economics     Hybrid Journal   (Followers: 4, SJR: 0.539, h-index: 29)
J. of Database Marketing & Customer Strategy Management     Hybrid Journal   (Followers: 8, SJR: 0.149, h-index: 8)
J. of Derivatives & Hedge Funds     Hybrid Journal   (Followers: 8, SJR: 0.114, h-index: 5)
J. of Developmental and Physical Disabilities     Hybrid Journal   (Followers: 8, SJR: 0.574, h-index: 29)
J. of Digital Imaging     Hybrid Journal   (Followers: 10, SJR: 0.578, h-index: 35)
J. of Direct Data and Digital Marketing Practice     Hybrid Journal   (Followers: 8, SJR: 0.154, h-index: 6)
J. of Dynamical and Control Systems     Hybrid Journal   (Followers: 2, SJR: 0.4, h-index: 26)
J. of Dynamics and Differential Equations     Hybrid Journal   (SJR: 1.418, h-index: 31)
J. of Earth Science     Hybrid Journal   (Followers: 8, SJR: 0.483, h-index: 16)
J. of Earth System Science     Open Access   (Followers: 43, SJR: 0.448, h-index: 32)
J. of East Asian Linguistics     Hybrid Journal   (Followers: 6, SJR: 0.537, h-index: 20)
J. of Echocardiography     Hybrid Journal   (Followers: 4, SJR: 0.22, h-index: 3)
J. of Economic Growth     Hybrid Journal   (Followers: 27, SJR: 3.273, h-index: 63)
J. of Economic Interaction and Coordination     Hybrid Journal   (SJR: 0.263, h-index: 12)
J. of Economics     Hybrid Journal   (Followers: 17, SJR: 0.418, h-index: 23)
J. of Economics and Finance     Hybrid Journal   (Followers: 6, SJR: 0.272, h-index: 19)
J. of Educational Change     Hybrid Journal   (Followers: 7, SJR: 0.961, h-index: 21)
J. of Elasticity     Hybrid Journal   (Followers: 6, SJR: 0.851, h-index: 45)
J. of Electroceramics     Hybrid Journal   (SJR: 0.577, h-index: 57)
J. of Electronic Materials     Hybrid Journal   (Followers: 5, SJR: 0.609, h-index: 75)
J. of Electronic Testing     Hybrid Journal   (Followers: 2, SJR: 0.372, h-index: 27)
J. of Electronics (China)     Hybrid Journal   (Followers: 4, SJR: 0.112, h-index: 9)
J. of Elementary Science Education     Hybrid Journal   (Followers: 9)
J. of Engineering Mathematics     Hybrid Journal   (SJR: 0.347, h-index: 37)
J. of Engineering Physics and Thermophysics     Hybrid Journal   (Followers: 1, SJR: 0.288, h-index: 11)
J. of Engineering Research     Open Access   (Followers: 1, SJR: 0.145, h-index: 5)
J. of Engineering Thermophysics     Hybrid Journal   (Followers: 2, SJR: 0.763, h-index: 9)
J. of Environmental Studies and Sciences     Partially Free   (Followers: 2)
J. of Ethology     Hybrid Journal   (Followers: 2, SJR: 0.609, h-index: 25)
J. of Evolution Equations     Hybrid Journal   (SJR: 0.826, h-index: 26)
J. of Evolutionary Biochemistry and Physiology     Hybrid Journal   (SJR: 0.145, h-index: 11)
J. of Evolutionary Economics     Hybrid Journal   (Followers: 8, SJR: 0.492, h-index: 52)
J. of Experimental and Theoretical Physics     Hybrid Journal   (Followers: 3, SJR: 0.458, h-index: 39)
J. of Experimental Criminology     Hybrid Journal   (Followers: 43, SJR: 1.445, h-index: 28)
J. of Failure Analysis and Prevention     Hybrid Journal   (Followers: 5, SJR: 0.261, h-index: 15)
J. of Family and Economic Issues     Hybrid Journal   (Followers: 6, SJR: 0.396, h-index: 32)
J. of Family Violence     Hybrid Journal   (Followers: 35, SJR: 0.639, h-index: 56)
J. of Financial Services Marketing     Hybrid Journal   (Followers: 3, SJR: 0.273, h-index: 10)
J. of Financial Services Research     Hybrid Journal   (Followers: 22, SJR: 0.572, h-index: 36)
J. of Fixed Point Theory and Applications     Hybrid Journal   (SJR: 0.644, h-index: 13)
J. of Fluorescence     Hybrid Journal   (Followers: 3, SJR: 0.465, h-index: 56)
J. of Food Measurement and Characterization     Hybrid Journal   (SJR: 0.307, h-index: 4)
J. of Food Science and Technology     Hybrid Journal   (Followers: 6, SJR: 0.441, h-index: 29)
J. of Forest Research     Hybrid Journal   (Followers: 3, SJR: 0.495, h-index: 27)
J. of Forestry Research     Hybrid Journal   (Followers: 6, SJR: 0.304, h-index: 14)
J. of Fourier Analysis and Applications     Hybrid Journal   (Followers: 1, SJR: 1.18, h-index: 42)
J. of Friction and Wear     Hybrid Journal   (Followers: 7, SJR: 0.373, h-index: 7)
J. of Fusion Energy     Hybrid Journal   (Followers: 3, SJR: 0.387, h-index: 19)
J. of Gambling Studies     Hybrid Journal   (Followers: 6, SJR: 1.171, h-index: 57)
J. of Gastroenterology     Hybrid Journal   (Followers: 12, SJR: 1.651, h-index: 88)
J. of Gastrointestinal Cancer     Hybrid Journal   (Followers: 3, SJR: 0.304, h-index: 39)
J. of Gastrointestinal Surgery     Hybrid Journal   (Followers: 6, SJR: 1.64, h-index: 99)
J. of General Internal Medicine     Hybrid Journal   (Followers: 16, SJR: 1.804, h-index: 134)
J. of General Plant Pathology     Hybrid Journal   (SJR: 0.554, h-index: 22)
J. of Genetic Counseling     Hybrid Journal   (Followers: 5, SJR: 0.902, h-index: 39)
J. of Genetics     Open Access   (Followers: 4, SJR: 0.458, h-index: 28)
J. of Geodesy     Hybrid Journal   (Followers: 8, SJR: 2.173, h-index: 56)
J. of Geographical Sciences     Hybrid Journal   (Followers: 1, SJR: 0.8, h-index: 23)
J. of Geographical Systems     Hybrid Journal   (Followers: 4, SJR: 0.822, h-index: 39)
J. of Geometric Analysis     Hybrid Journal   (SJR: 1.491, h-index: 27)
J. of Geometry     Hybrid Journal   (Followers: 1, SJR: 0.272, h-index: 15)
J. of Global Optimization     Hybrid Journal   (Followers: 4, SJR: 0.992, h-index: 60)
J. of Global Policy and Governance     Hybrid Journal   (Followers: 10)
J. of Grid Computing     Hybrid Journal   (Followers: 1, SJR: 1.414, h-index: 37)
J. of Hand and Microsurgery     Hybrid Journal   (Followers: 1)
J. of Happiness Studies     Hybrid Journal   (Followers: 23, SJR: 0.881, h-index: 39)
J. of Hematopathology     Hybrid Journal   (Followers: 4, SJR: 0.2, h-index: 13)
J. of Heuristics     Hybrid Journal   (Followers: 5, SJR: 1.308, h-index: 50)
J. of High Energy Physics     Hybrid Journal   (Followers: 19, SJR: 1.052, h-index: 153)
J. of Homotopy and Related Structures     Hybrid Journal   (SJR: 0.232, h-index: 2)
J. of Housing and the Built Environment     Hybrid Journal   (Followers: 7, SJR: 0.648, h-index: 28)
J. of Huazhong University of Science and Technology [Medical Sciences]     Hybrid Journal   (SJR: 0.344, h-index: 19)
J. of Ichthyology     Hybrid Journal   (Followers: 3, SJR: 0.304, h-index: 10)
J. of Immigrant and Minority Health     Hybrid Journal   (Followers: 11, SJR: 0.759, h-index: 37)
J. of Inclusion Phenomena and Macrocyclic Chemistry     Hybrid Journal   (Followers: 1, SJR: 0.331, h-index: 46)
J. of Indian Council of Philosophical Research     Hybrid Journal  
J. of Indian Philosophy     Hybrid Journal   (Followers: 12, SJR: 0.127, h-index: 12)
J. of Industrial Microbiology and Biotechnology     Hybrid Journal   (Followers: 15, SJR: 0.966, h-index: 80)
J. of Industry, Competition and Trade     Hybrid Journal   (Followers: 8, SJR: 0.327, h-index: 15)
J. of Infection and Chemotherapy     Hybrid Journal   (Followers: 1, SJR: 0.673, h-index: 46)
J. of Information Technology     Hybrid Journal   (Followers: 54, SJR: 1.474, h-index: 55)
J. of Information Technology Teaching Cases     Hybrid Journal   (Followers: 9)
J. of Infrared, Millimeter and Terahertz Waves     Hybrid Journal   (Followers: 2, SJR: 1.25, h-index: 36)
J. of Inherited Metabolic Disease     Hybrid Journal   (Followers: 2, SJR: 1.389, h-index: 77)
J. of Inorganic and Organometallic Polymers and Materials     Partially Free   (Followers: 9, SJR: 0.338, h-index: 33)
J. of Insect Behavior     Hybrid Journal   (Followers: 9, SJR: 0.569, h-index: 39)
J. of Insect Conservation     Hybrid Journal   (Followers: 10, SJR: 0.872, h-index: 43)
J. of Intelligent and Robotic Systems     Hybrid Journal   (Followers: 2, SJR: 0.629, h-index: 43)
J. of Intelligent Information Systems     Hybrid Journal   (Followers: 1, SJR: 0.691, h-index: 43)
J. of Intelligent Manufacturing     Hybrid Journal   (Followers: 3, SJR: 1.397, h-index: 54)
J. of Interventional Cardiac Electrophysiology     Hybrid Journal   (SJR: 0.93, h-index: 43)
J. of Intl. Business Studies     Hybrid Journal   (Followers: 31, SJR: 4.208, h-index: 130)
J. of Intl. Entrepreneurship     Hybrid Journal   (Followers: 9, SJR: 0.549, h-index: 23)
J. of Intl. Migration and Integration / Revue de l integration et de la migration internationale     Hybrid Journal   (Followers: 13, SJR: 0.308, h-index: 13)
J. of Intl. Relations and Development     Hybrid Journal   (Followers: 20, SJR: 0.793, h-index: 22)
J. of Labor Research     Hybrid Journal   (Followers: 17, SJR: 0.394, h-index: 27)
J. of Logic, Language and Information     Hybrid Journal   (Followers: 7, SJR: 0.288, h-index: 25)
J. of Low Temperature Physics     Hybrid Journal   (Followers: 3, SJR: 0.531, h-index: 52)
J. of Machinery Manufacture and Reliability     Hybrid Journal   (Followers: 2, SJR: 0.203, h-index: 7)
J. of Mammalian Evolution     Hybrid Journal   (Followers: 5, SJR: 1.134, h-index: 37)
J. of Mammary Gland Biology and Neoplasia     Hybrid Journal   (Followers: 2, SJR: 2.252, h-index: 83)
J. of Management and Governance     Hybrid Journal   (Followers: 13, SJR: 0.805, h-index: 33)
J. of Management Control     Hybrid Journal   (Followers: 4, SJR: 0.605, h-index: 6)
J. of Marine Science and Application     Hybrid Journal   (Followers: 3, SJR: 0.439, h-index: 11)
J. of Marine Science and Technology     Hybrid Journal   (Followers: 3, SJR: 0.235, h-index: 19)
J. of Maritime Archaeology     Hybrid Journal   (Followers: 21, SJR: 0.228, h-index: 8)
J. of Market-Focused Management     Hybrid Journal   (Followers: 2)
J. of Marketing Analytics     Hybrid Journal   (Followers: 4)
J. of Material Cycles and Waste Management     Hybrid Journal   (Followers: 3, SJR: 0.449, h-index: 22)
J. of Materials Engineering and Performance     Hybrid Journal   (Followers: 22, SJR: 0.544, h-index: 40)
J. of Materials Science     Hybrid Journal   (Followers: 20, SJR: 0.836, h-index: 123)
J. of Materials Science : Materials in Electronics     Hybrid Journal   (Followers: 5)
J. of Materials Science : Materials in Medicine     Hybrid Journal   (Followers: 5)
J. of Mathematical Biology     Hybrid Journal   (Followers: 12, SJR: 1.011, h-index: 71)
J. of Mathematical Chemistry     Hybrid Journal   (Followers: 5, SJR: 0.497, h-index: 45)
J. of Mathematical Fluid Mechanics     Hybrid Journal   (Followers: 6, SJR: 1.22, h-index: 22)
J. of Mathematical Imaging and Vision     Hybrid Journal   (Followers: 4, SJR: 0.901, h-index: 53)
J. of Mathematical Modelling and Algorithms     Hybrid Journal   (Followers: 2, SJR: 0.414, h-index: 23)
J. of Mathematical Sciences     Hybrid Journal   (SJR: 0.272, h-index: 23)
J. of Mathematics Teacher Education     Hybrid Journal   (Followers: 15, SJR: 1.062, h-index: 20)
J. of Maxillofacial and Oral Surgery     Hybrid Journal   (Followers: 2)
J. of Mechanical Science and Technology     Hybrid Journal   (Followers: 6, SJR: 0.589, h-index: 26)
J. of Medical and Biological Engineering     Hybrid Journal   (Followers: 1, SJR: 0.387, h-index: 18)
J. of Medical Humanities     Hybrid Journal   (Followers: 22, SJR: 0.299, h-index: 18)
J. of Medical Systems     Hybrid Journal   (Followers: 1, SJR: 0.717, h-index: 44)
J. of Medical Toxicology     Hybrid Journal   (Followers: 4, SJR: 0.874, h-index: 28)
J. of Medical Ultrasonics     Hybrid Journal   (Followers: 2, SJR: 0.18, h-index: 13)
J. of Medicine and the Person     Hybrid Journal  
J. of Membrane Biology     Hybrid Journal   (Followers: 2, SJR: 0.738, h-index: 82)
J. of Micro-Bio Robotics     Hybrid Journal   (SJR: 0.28, h-index: 3)
J. of Microbiology     Hybrid Journal   (Followers: 8, SJR: 0.741, h-index: 43)
J. of Mining Science     Hybrid Journal   (Followers: 5, SJR: 0.317, h-index: 16)
J. of Molecular Evolution     Hybrid Journal   (Followers: 9, SJR: 0.952, h-index: 108)
J. of Molecular Histology     Hybrid Journal   (Followers: 2, SJR: 0.755, h-index: 48)
J. of Molecular Medicine     Hybrid Journal   (Followers: 16, SJR: 2.165, h-index: 113)
J. of Molecular Modeling     Hybrid Journal   (Followers: 4, SJR: 0.466, h-index: 50)
J. of Molecular Neuroscience     Partially Free   (Followers: 11, SJR: 0.988, h-index: 69)
J. of Mountain Science     Hybrid Journal   (Followers: 4, SJR: 0.418, h-index: 15)
J. of Muscle Research and Cell Motility     Hybrid Journal   (Followers: 1, SJR: 1.264, h-index: 55)
J. of Nanoparticle Research     Hybrid Journal   (Followers: 3, SJR: 0.583, h-index: 84)
J. of Natural Medicines     Hybrid Journal   (SJR: 0.602, h-index: 28)
J. of Near-Death Studies     Hybrid Journal   (Followers: 2)
J. of Nephrology     Hybrid Journal   (Followers: 4, SJR: 0.689, h-index: 55)
J. of Network and Systems Management     Hybrid Journal   (SJR: 0.466, h-index: 26)
J. of Neural Transmission     Hybrid Journal   (Followers: 2, SJR: 1.034, h-index: 86)
J. of Neuro-Oncology     Hybrid Journal   (Followers: 3, SJR: 1.274, h-index: 90)
J. of Neuroimmune Pharmacology     Hybrid Journal   (Followers: 1, SJR: 1.662, h-index: 45)
J. of Neurology     Hybrid Journal   (Followers: 15, SJR: 1.429, h-index: 105)
J. of NeuroVirology     Hybrid Journal   (Followers: 1, SJR: 0.979, h-index: 69)
J. of Nondestructive Evaluation     Hybrid Journal   (Followers: 9, SJR: 0.863, h-index: 27)
J. of Nonlinear Science     Hybrid Journal   (Followers: 1, SJR: 1.887, h-index: 42)
J. of Nonverbal Behavior     Hybrid Journal   (Followers: 5, SJR: 0.723, h-index: 47)
J. of Nuclear Cardiology     Hybrid Journal   (SJR: 1.024, h-index: 68)
J. of Nutrition, Health and Aging     Hybrid Journal   (Followers: 21, SJR: 0.919, h-index: 60)
J. of Obstetrics and Gynecology of India     Hybrid Journal   (Followers: 6, SJR: 0.214, h-index: 6)
J. of Occupational Rehabilitation     Hybrid Journal   (Followers: 15, SJR: 0.811, h-index: 51)
J. of Ocean Engineering and Marine Energy     Hybrid Journal   (Followers: 2)
J. of Ocean University of China (English Edition)     Hybrid Journal   (Followers: 1, SJR: 0.237, h-index: 11)
J. of Oceanography     Hybrid Journal   (Followers: 9, SJR: 0.796, h-index: 52)
J. of Ocular Biology, Diseases, and Informatics     Hybrid Journal   (SJR: 0.183, h-index: 11)
J. of Optical and Fiber Communications Reports     Hybrid Journal   (Followers: 3)
J. of Optics     Hybrid Journal   (Followers: 8, SJR: 0.214, h-index: 8)
J. of Optimization Theory and Applications     Hybrid Journal   (Followers: 4, SJR: 0.898, h-index: 65)
J. of Ornithology     Hybrid Journal   (Followers: 22)
J. of Orofacial Orthopedics / Fortschritte der Kieferorthopädie     Hybrid Journal   (SJR: 0.574, h-index: 33)
J. of Orthopaedic Science     Hybrid Journal   (Followers: 6, SJR: 0.708, h-index: 48)
J. of Paleolimnology     Hybrid Journal   (Followers: 5, SJR: 0.984, h-index: 64)
J. of Parasitic Diseases     Hybrid Journal   (Followers: 2, SJR: 0.298, h-index: 9)
J. of Pediatric Neuropsychology     Hybrid Journal   (Followers: 3)
J. of Pest Science     Hybrid Journal   (Followers: 2, SJR: 1.341, h-index: 28)
J. of Pharmaceutical Health Care and Sciences     Open Access  
J. of Pharmaceutical Innovation     Hybrid Journal   (Followers: 8, SJR: 0.524, h-index: 17)
J. of Pharmaceutical Investigation     Hybrid Journal   (SJR: 0.331, h-index: 6)
J. of Pharmacokinetics and Pharmacodynamics     Hybrid Journal   (Followers: 18, SJR: 0.708, h-index: 46)

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Journal Cover Experiments in Fluids
  [SJR: 1.088]   [H-I: 82]   [11 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 1432-1114 - ISSN (Online) 0723-4864
   Published by Springer-Verlag Homepage  [2340 journals]
  • Data assimilation of mean velocity from 2D PIV measurements of flow over
           an idealized airfoil
    • Authors: Sean Symon; Nicolas Dovetta; Beverley J. McKeon; Denis Sipp; Peter J. Schmid
      Abstract: Abstract Data assimilation can be used to combine experimental and numerical realizations of the same flow to produce hybrid flow fields. These have the advantages of less noise contamination and higher resolution while simultaneously reproducing the main physical features of the measured flow. This study investigates data assimilation of the mean flow around an idealized airfoil (Re = 13,500) obtained from time-averaged two-dimensional particle image velocimetry (PIV) data. The experimental data, which constitute a low-dimensional representation of the full flow field due to resolution and field-of-view limitations, are incorporated into a simulation governed by the two-dimensional, incompressible Reynolds-averaged Navier–Stokes (RANS) equations with an unknown momentum forcing. This forcing, which corresponds to the divergence of the Reynolds stress tensor, is calculated from a direct-adjoint optimization procedure to match the experimental and numerical mean velocity fields. The simulation is projected onto the low-dimensional subspace of the experiment to calculate the discrepancy and a smoothing procedure is used to recover adjoint solutions on the higher dimensional subspace of the simulation. The study quantifies how well data assimilation can reconstruct the mean flow and the minimum experimental measurements needed by altering the resolution and domain size of the time-averaged PIV.
      PubDate: 2017-04-22
      DOI: 10.1007/s00348-017-2336-8
      Issue No: Vol. 58, No. 5 (2017)
       
  • Afterbody vortices of axisymmetric cylinders with a slanted base
    • Authors: D. S. Bulathsinghala; R. Jackson; Z. Wang; I. Gursul
      Abstract: Abstract Experiments have been undertaken to study the formation of afterbody vortex flows from cylindrical bodies with a slanted base, whose upsweep angle was varied between 24° and 32°. Vortex roll-up is mostly completed in the first half of the upswept section, where the vortex causes largest suction on the surface. Towards the trailing-edge the vortices become more axisymmetric and stronger with increasing upsweep angle. Although there is some delay in vortex roll-up at lower Reynolds number, the main features of the vortex flow are similar to those at higher Reynolds number. The strength of the vortices at the trailing-edge was proportional to the time-averaged drag coefficient, which increased by nearly 50% in the range of upsweep angles tested. The vortex was more coherent with reduced meandering and a smaller core radius towards the trailing-edge. This reduction in meandering along the streamwise direction had not been observed previously with other external vortex flows in aerodynamics. Proper Orthogonal Decomposition revealed that the helical displacement mode with azimuthal wavenumber m = 1 was the dominant mode towards the trailing-edge, suggesting that the afterbody vortices bear much similarity with the more widely studied wing tip vortices and delta wing vortices. The instantaneous vortex pair exhibits time-dependent asymmetry; however, there is virtually no correlation between the displacements of the vortex centers.
      PubDate: 2017-04-22
      DOI: 10.1007/s00348-017-2343-9
      Issue No: Vol. 58, No. 5 (2017)
       
  • Optimization of planar PIV-based pressure estimates in laminar and
           turbulent wakes
    • Authors: Jeffrey McClure; Serhiy Yarusevych
      Abstract: Abstract The performance of four pressure estimation techniques using Eulerian material acceleration estimates from planar, two-component Particle Image Velocimetry (PIV) data were evaluated in a bluff body wake. To allow for the ground truth comparison of the pressure estimates, direct numerical simulations of flow over a circular cylinder were used to obtain synthetic velocity fields. Direct numerical simulations were performed for \(Re_\mathrm{D} = 100\) , 300, and 1575, spanning laminar, transitional, and turbulent wake regimes, respectively. A parametric study encompassing a range of temporal and spatial resolutions was performed for each \(Re_\mathrm{D}\) . The effect of random noise typical of experimental velocity measurements was also evaluated. The results identified optimal temporal and spatial resolutions that minimize the propagation of random and truncation errors to the pressure field estimates. A model derived from linear error propagation through the material acceleration central difference estimators was developed to predict these optima, and showed good agreement with the results from common pressure estimation techniques. The results of the model are also shown to provide acceptable first-order approximations for sampling parameters that reduce error propagation when Lagrangian estimations of material acceleration are employed. For pressure integration based on planar PIV, the effect of flow three-dimensionality was also quantified, and shown to be most pronounced at higher Reynolds numbers downstream of the vortex formation region, where dominant vortices undergo substantial three-dimensional deformations. The results of the present study provide a priori recommendations for the use of pressure estimation techniques from experimental PIV measurements in vortex dominated laminar and turbulent wake flows.
      PubDate: 2017-04-22
      DOI: 10.1007/s00348-017-2337-7
      Issue No: Vol. 58, No. 5 (2017)
       
  • Attenuation of sweep events in a turbulent boundary layer using
           micro-cavities
    • Authors: Anton Silvestri; Farzin Ghanadi; Maziar Arjomandi; Benjamin Cazzolato; Anthony Zander
      Abstract: Abstract In the present study, the turbulent energy production within a fully developed turbulent boundary layer has been reduced using a variety of flushed-surface cavity arrays with different geometries embedded within a flat plate. The cavity arrays manipulate the sweep events in the boundary layer by capturing and damping their duration and intensity. The size of the holes in the cavity array was selected to be comparable with the dimensions of the expected coherent structures, based on the friction velocity and the known spacing and sizing of the sweep events. The velocity fluctuations within the turbulent boundary layer were measured using hot-wire anemometry in a wind tunnel for a range of Reynolds numbers. The results show that when the orifice diameter is equal to a value of 60 times the viscous length scale there is a maximum reduction in the turbulence and sweep intensities of 13 and 14%, respectively. The results also demonstrated that for a cavity orifice diameter less than 20 times the viscous length scale, the sweep events are restricted and no events are captured by the array. Furthermore, if the diameter of the orifice exceeds 145 times the viscous length scale, separation of the shear layer occurs, causing an increase in the turbulence energy production in the near-wall region.
      PubDate: 2017-04-19
      DOI: 10.1007/s00348-017-2345-7
      Issue No: Vol. 58, No. 5 (2017)
       
  • Passive scalar mixing studies to identify the mixing length in a
           supersonic confined jet
    • Authors: S. K. Karthick; Srisha M. V. Rao; G. Jagadeesh; K. P. J. Reddy
      Abstract: Abstract Supersonic jet with a co-flow, closely bounded by walls is known as supersonic confined jet. Supersonic confined jet is encountered in practical devices like the supersonic ejector. Mixing of the primary and the secondary fluid inside the confined passage is complex. From a design perspective, it is necessary to have an accurate knowledge of the mixing length (L MIX). Tracers that do not actively participate in the flow behavior but rather mark the fluids such that they faithfully follow the fluid motion are known as passive scalars. Passive scalars help in the understanding the progression of mixing amidst interacting flows. In this work, we have performed passive scalar mixing studies in a supersonic confined jet for different operating conditions using an existing low area ratio (AR = 3.7) rectangular supersonic gaseous ejector. Air is used as the working fluid in both the primary and the secondary flow. The design Mach number of the primary flow nozzle (M PD = 1.5–3.0) and the total pressure of the primary flow (P OP = 4.89–9.89 bar) are varied during the experiments. Using the planar laser-induced fluorescence (PLIF) technique and acetone as the passive scalar, L MIX is determined. A 266 nm Nd-YAG laser with a repetition rate of 8 Hz is used to excite the acetone molecules in the flow field, and the emitted fluorescence is captured by an ICCD camera. A new method is proposed to study the passive scalar distribution from the acetone PLIF images through digital image processing. Spatial Scalar Fluctuations Intensity (SSFI or ψ) is a parameter defined at every transverse section along the flow direction. Based on the variation of ψ along the jet, the location of L MIX can be identified. L MIX is defined as the length from the supersonic nozzle exit where ψ first attains a value of 0.05. For the first time, L MIX is quantified in a supersonic confined jet. L MIX values are observed to be in the range of 3H to 6H for the cases under study, where H is the height of the confined passage. The behavior of L MIX is closely dependent on the nozzle operating conditions. The values of L MIX are found to be reduced by 17.67% for the over-expanded flows and increased by 15.76% for the under-expanded flows from the perfectly expanded condition. This study also provides other supersonic confined jet characteristics like the potential core length (L PC) and the shock cell spacing (S x) of the primary supersonic jet. Compared to the supersonic free jet, values of L PC and S x are found to be different in the supersonic confined jet.
      PubDate: 2017-04-19
      DOI: 10.1007/s00348-017-2342-x
      Issue No: Vol. 58, No. 5 (2017)
       
  • Suppressing prompt splash with polymer additives
    • Authors: E. J. Vega; A. A. Castrejón-Pita
      Abstract: Abstract Splash suppression during drop impact continues to be a grand challenge. To date, only a few techniques for the complete suppression of splash exist. Reducing the ambient pressure and using complex surfaces (microstructured and/or soft) are two of the recently discovered ones which may not be very practical in many technological processes. The idea of using additives directly into the liquid used to produce the drops, to inhibit this undesirable phenomenon, is, therefore, desired. Prompt splash is a type of splashing that releases diminutive droplets at high speeds from the tip of the lamella at the spreading liquid-substrate contact line immediately after the impact (within the first 10 μm), without generating the typical thin-sheet or corona. Prompt splash remained hidden for many years until high-speed imaging allowed for its visualisation. Here, we demonstrate that by adding very low amounts of polymer (around 0.01 wt%) into normally splashing water droplets a reduction and even a complete suppression of the prompt splash is observed. In this work, a systematic experimental study of the impact of viscoelastic drops, by varying size, impact velocity, and the “degree” of viscoelasticity, is conducted. When capillary forces are insufficient to maintain the integrity of the drop, elastic forces seem to pull the attached small droplets/fingers back to the lamella preventing their ejection and, therefore, inhibiting prompt splash. However, surprisingly, larger quantities of the polymer additive lead to a secondary transition, in which another, more common, type of splash is induced: corona splash.
      PubDate: 2017-04-18
      DOI: 10.1007/s00348-017-2341-y
      Issue No: Vol. 58, No. 5 (2017)
       
  • Invariant Type-B characteristics of drag-reducing microalgal biopolymer
           solutions
    • Authors: K. Gasljevic; K. Hall; D. Chapman; E. F. Matthys
      Abstract: Abstract The drag-reducing properties of polysaccharides from marine microalgae were investigated. They were compared to two drag-reducing additives studied extensively in the past, synthetic poly(ethylene) oxide, one of the most effective drag-reducing additives; and Xanthan Gum, another biopolymer often considered a model polymer for chemical and rheological research. Compared to Xanthan Gum, the most effective polymers from our microalgae show a higher drag-reducing efficiency in terms of necessary concentration to achieve a given level of drag reduction. In addition, they show a striking Type-B drag reduction behavior, which may be a very useful quality in most drag reduction applications, thanks to the independence of the drag reduction level on flow conditions such as velocity, shear stress, and tube diameter. With these polymers from microalgae we did not see evidence of Type-A behavior over the wide range of conditions studied (including pipe diameters up to 52 mm). Importantly, this suggests that the Drag Reduction coefficient in pipe flow for ideal drag-reducing solutions such as the polysaccharides investigated here is invariant at a given additive concentration of flow or solution parameters like ionic strength and can be used as a solution property to predict its drag reduction effectiveness over a wide range of conditions. On the contrary, Xanthan Gum showed evidence of both Type-A behavior in large diameter pipes and Type-B behavior in smaller ones. The polymers from microalgae also showed high resistance to degradation. Considering that these microalgae are very effective producers of polysaccharides (both extracellular and intracellular), they appear to be very promising additives for drag reduction applications.
      PubDate: 2017-04-11
      DOI: 10.1007/s00348-017-2338-6
      Issue No: Vol. 58, No. 5 (2017)
       
  • The effect of velocity filtering in pressure estimation
    • Authors: D. E. Schiavazzi; A. Nemes; S. Schmitter; F. Coletti
      Abstract: Abstract Velocity field measurements allow, in principle, the evaluation of the pressure field by integrating the equations of fluid motion. Unavoidable experimental uncertainty, however, may result in unreliable estimates. In this study, we use the Poisson pressure equation to estimate the relative pressure from experimental velocities, and investigate how pre-processing with smoothing and solenoidal filters affects this estimate. For diffusion dominated laminar flow or for turbulent flow modeled through an eddy viscosity, measurement noise significantly affects the results. In this case, solenoidal filtering provides superior performance over other smoothing approaches, as it preserves the second spatial derivatives of the velocity field. For laminar flows dominated by advection or acceleration components of the pressure gradient, the choice of the filter appears to have little effect under limited noise, while smoothing produces improved relative pressure estimates for higher noise intensities. The above statements are verified using idealized flow conditions, numerical fluid dynamics simulations, and velocity fields from in-vivo and in-vitro magnetic resonance velocimetry.
      PubDate: 2017-04-11
      DOI: 10.1007/s00348-017-2314-1
      Issue No: Vol. 58, No. 5 (2017)
       
  • A systematic experimental study on the evaporation rate of supercooled
           water droplets at subzero temperatures and varying relative humidity
    • Authors: S. Ruberto; J. Reutzsch; N. Roth; B. Weigand
      Abstract: Abstract Supercooled water droplets (SWD) are present in clouds at high altitude and subjected to very low temperatures and high relative humidity. These droplets exist in a metastable state. The understanding of the evaporation of SWD at these extreme conditions is of high interest to understand rain, snow, and hail generating mechanisms in clouds. This paper focuses on the experimental results of the measurements of the evaporation rates \(\beta\) of supercooled water droplets. For this purpose, single SWDs are trapped by means of optical levitation. During the evaporation process, the elastically scattered light in the forward regime is recorded and evaluated. Experiments have been performed for different relative humidities \(\phi\) at three constant ambient temperatures, namely, \({T_\infty }=268.15;~263.15;~253.15~{\text{K}}\) ( \({t_\infty } = -5;\,-10;\,-20~^{\circ}{\text{C}}\) ). The experimental data agrees well with direct numerical simulations (DNS) carried out with the in-house code Free Surface 3D (FS3D) and shows that the use of a simplified model is permissible for these ambient conditions.
      PubDate: 2017-04-11
      DOI: 10.1007/s00348-017-2339-5
      Issue No: Vol. 58, No. 5 (2017)
       
  • Flow and acoustic characteristics of non-axisymmetric jets at subsonic
           conditions
    • Authors: Puja Upadhyay; Griffin Valentich; Rajan Kumar; Farrukh Alvi
      Abstract: Abstract Flow and acoustic behavior of two asymmetric, rectangular (AR = 4) and elliptic (AR = 2.5), jets are studied and compared to an equivalent area round jet. The jets are operated at a Mach number of 0.9 and temperature ratio of 1. Time-averaged flow field measurements are carried out using planar and stereoscopic particle image velocimetry. In addition, far-field microphone measurements are performed to compare jet acoustics. Mean flow field results demonstrate that for the given Mach number and aspect ratios, rectangular and elliptic jet properties are somewhat modified compared to the round jet. The elliptic jet exhibits properties that are intermediate between two geometric extremes. Moderately enhanced mixing in asymmetric jets as a result of weak streamwise vortices is evidenced by overall shorter potential core, faster centerline velocity decay, and higher shear layer growth rates. Centerline turbulence levels and transverse shear stress distribution also show enhanced fluctuations for non-circular jets. Compared to their major axis planes, relatively higher turbulence levels are measured in the minor axis planes for both rectangular and elliptic jets. Far-field acoustic measurements reveal the asymmetric nature of the sound field. Compared to the round jet, major axis orientation for asymmetric jets is observed to provide moderate acoustic benefit in the downstream direction. However, enhanced fluctuations in the minor axis plane result in a marginal noise augmentation at moderate to high frequencies in this plane for downstream polar angles.
      PubDate: 2017-04-11
      DOI: 10.1007/s00348-017-2340-z
      Issue No: Vol. 58, No. 5 (2017)
       
  • Dynamic mode decomposition for estimating vortices and lee waves in a
           stratified wake
    • Authors: Xinjiang Xiang; Kevin K. Chen; Geoffrey R. Spedding
      Abstract: Abstract Dynamic mode decomposition (DMD) is an analysis technique for extracting flow patterns and their dynamics from experimental or simulated velocity fields. Here, DMD is applied to experimental data in the vertical center-plane of wakes generated by a towed grid in a stably stratified background, at varying values of the dimensionless Froude and Reynolds Number. The primary goal was to identify dynamically important patterns and reveal the influence of stratification on their initiation and evolution. It is demonstrated that DMD captures lee wave and vortical modes with different length scales successfully. Further, one can construct a mode energy spectrum which shows a clear dependence on Froude Number, with energy transfer to larger scales in the near wake, as the initial shear-triggered Kelvin–Helmholtz roll-ups diffuse and pair with neighbors. Finally, this paper serves as a detailed example of the application of DMD to time-resolved particle imaging velocimetry data for a stratified flow. The results confirm its utility in objective identification of dynamics at different scales of complex fluid flows.
      PubDate: 2017-04-11
      DOI: 10.1007/s00348-017-2344-8
      Issue No: Vol. 58, No. 5 (2017)
       
  • Turbulent stress measurements with phase-contrast magnetic resonance
           through tilted slices
    • Authors: Jordan MacKenzie; Daniel Söderberg; Agne Swerin; Fredrik Lundell
      Abstract: Abstract Aiming at turbulent measurements in opaque suspensions, a simplistic methodology for measuring the turbulent stresses with phase-contrast magnetic resonance velocimetry is described. The method relies on flow-compensated and flow-encoding protocols with the flow encoding gradient normal to the slice. The experimental data is compared with direct numerical simulations (DNS), both directly but also, more importantly, after spatial averaging of the DNS data that resembles the measurement and data treatment of the experimental data. The results show that the most important MRI data (streamwise velocity, streamwise variance and Reynolds shear stress) is reliable up to at least \({\bar{r}} = 0.75\) without any correction, paving the way for dearly needed turbulence and stress measurements in opaque suspensions.
      PubDate: 2017-04-11
      DOI: 10.1007/s00348-017-2328-8
      Issue No: Vol. 58, No. 5 (2017)
       
  • PIV-based estimation of unsteady loads on a flat plate at high angle of
           attack using momentum equation approaches
    • Authors: A. Guissart; L. P. Bernal; G. Dimitriadis; V. E. Terrapon
      Abstract: Abstract This work presents, compares and discusses results obtained with two indirect methods for the calculation of aerodynamic forces and pitching moment from 2D Particle Image Velocimetry (PIV) measurements. Both methodologies are based on the formulations of the momentum balance: the integral Navier–Stokes equations and the “flux equation” proposed by Noca et al. (J Fluids Struct 13(5):551–578, 1999), which has been extended to the computation of moments. The indirect methods are applied to spatio-temporal data for different separated flows around a plate with a \(16\mathrm {:}1\) chord-to-thickness ratio. Experimental data are obtained in a water channel for both a plate undergoing a large amplitude imposed pitching motion and a static plate at high angle of attack. In addition to PIV data, direct measurements of aerodynamic loads are carried out to assess the quality of the indirect calculations. It is found that indirect methods are able to compute the mean and the temporal evolution of the loads for two-dimensional flows with a reasonable accuracy. Nonetheless, both methodologies are noise sensitive, and the parameters impacting the computation should thus be chosen carefully. It is also shown that results can be improved through the use of dynamic mode decomposition (DMD) as a pre-processing step.
      PubDate: 2017-04-11
      DOI: 10.1007/s00348-017-2335-9
      Issue No: Vol. 58, No. 5 (2017)
       
  • High-speed axial-scanning wide-field microscopy for volumetric particle
           tracking velocimetry
    • Authors: T.-H. Chen; J. T. Ault; H. A. Stone; C. B. Arnold
      Abstract: Abstract The ability to understand and visualize complex flow structures in microfluidic and biological systems relies heavily on the resolving power of three-dimensional (3D) particle velocimetry techniques. We propose a simple technique for acquiring volumetric particle information with the potential for microsecond time resolution. By utilizing a fast varifocal lens in a modified wide-field microscope, we capture both volumetric and planar information with microsecond time resolution. The technique is demonstrated by tracking particle motions in the complex, three-dimensional flow in a high Reynolds number laminar flow at a branching arrow-shaped junction.
      PubDate: 2017-04-03
      DOI: 10.1007/s00348-017-2316-z
      Issue No: Vol. 58, No. 5 (2017)
       
  • Reduction of freestream turbulence at low velocities
    • Authors: Dominik K. Puckert; Michael Dieterle; Ulrich Rist
      Abstract: Abstract Controlling freestream turbulence (FST) in low-turbulence wind or water channels is a common challenge and often difficult to achieve. Particularly at low velocities, design guidelines from literature may not fulfill their purpose and thus require alternative strategies. In this study, we propose the installation of a fine-meshed screen downstream of the contraction and not in the settling chamber as typically advised in literature. With this strategy, the lower operational limitation of our facility could be extended below \(U_{\infty }= 0.06\,\text {ms}^{-1}\) and the turbulence intensity reduced by \(60 \%\) at 0.04 ms \(^{-1}\) . This is not only an improvement of freestream conditions but also the key to experiments in the laminar boundary layer, which is highly sensitive to FST. In fact, two fundamentally different transition mechanism can be distinguished with this approach.
      PubDate: 2017-04-03
      DOI: 10.1007/s00348-017-2333-y
      Issue No: Vol. 58, No. 5 (2017)
       
  • 3D reconstruction of a compressible flow by synchronized multi-camera BOS
    • Authors: F. Nicolas; D. Donjat; O. Léon; G. Le Besnerais; F. Champagnat; F. Micheli
      Abstract: Abstract This paper investigates the application of a 3D density reconstruction from a limited number of background-oriented schlieren (BOS) images as recently proposed in Nicolas et al. (Exp Fluids 57(1):1–21, 2016), to the case of compressible flows, such as underexpanded jets. First, an optimization of a 2D BOS setup is conducted to mitigate the intense local blurs observed in raw BOS images and caused by strong density gradients present in the jets. It is demonstrated that a careful choice of experimental conditions enables one to obtain sharp deviation fields from 2D BOS images. Second, a 3DBOS experimental bench involving 12 synchronized cameras is specifically designed for the present study. It is shown that the 3DBOS method can provide physically consistent 3D reconstructions of instantaneous and mean density fields for various underexpanded jet flows issued into quiescent air. Finally, an analysis of the density structure of a moderately underexpanded jet is conducted through phase-averaging, highlighting the development of a large-scale coherent structure associated with a jet shear layer instability.
      PubDate: 2017-04-03
      DOI: 10.1007/s00348-017-2325-y
      Issue No: Vol. 58, No. 5 (2017)
       
  • Intrusive effects of repetitive laser pulsing in high-speed tracer-LIF
           measurements
    • Authors: M. Papageorge; J. A. Sutton
      Abstract: Abstract The effects of repetitive laser pulsing on laser-induced fluorescence (LIF) signals from three popular organic flow tracers, acetone, 3-pentanone, and biacetyl are examined experimentally in the context of high-speed PLIF imaging. The effects of varying the incident laser fluence, laser repetition rates, tracer mole fractions, and carrier gas (air or N2) are investigated. Repetitive laser pulsing leads to changes in the measured LIF signal as a function of laser pulse number for all three tracers. For biacetyl/air mixtures, the LIF signal increases as a function of pulse number and the LIF signal increase per pulse is observed to be a function of the incident laser fluence. For biacetyl/air mixtures at room temperature, the increase in LIF signal during repetitive laser pulsing is attributed solely to absorptive heating of the probe volume, which is confirmed by Rayleigh scattering thermometry measurements. For acetone and 3-pentanone mixtures in the air, the LIF signal decreases with increasing pulse number and the LIF signal depletion per pulse is a linear function of incident laser fluence. This allows the signal depletion per pulse from acetone and 3-pentanone to be normalized by laser fluence and generalized to a single parameter of 0.002%/pulse/(mJ/cm2). There is no discernable effect of varying the tracer mole fraction or the laser repetition rate over the range of values investigated. The substitution of N2 for the air as a carrier gas leads to a significant decrease in the signal depletion per pulse. The potential mechanisms for the enhanced signal depletion in the presence of oxygen are discussed. A likely source is “photo-oxidation”, where the products of laser photolysis react with the surrounding O2 to form the highly reactive hydroxyl (OH) radical, which then oxidizes the tracer. Overall, the current results indicate that under repetitive laser pulsing conditions (i.e., high-speed imaging), the tracer-LIF measurement techniques can be considered intrusive unless the laser fluences are kept sufficiently low. The implications for turbulent flow measurements are discussed including recommendations for minimizing the intrusive repetitive pulsing effects.
      PubDate: 2017-04-03
      DOI: 10.1007/s00348-017-2323-0
      Issue No: Vol. 58, No. 5 (2017)
       
  • Schlieren technique in soap film flows
    • Authors: M. I. Auliel; F. Castro Hebrero; R. Sosa; G. Artana
      Abstract: Abstract We propose the use of the Schlieren technique as a tool to analyse the flows in soap film tunnels. The technique enables to visualize perturbations of the film produced by the interposition of an object in the flow. The variations of intensity of the image are produced as a consequence of the deviations of the light beam traversing the deformed surfaces of the film. The quality of the Schlieren image is compared to images produced by the conventional interferometric technique. The analysis of Schlieren images of a cylinder wake flow indicates that this technique enables an easy visualization of vortex centers. Post-processing of series of two successive images of a grid turbulent flow with a dense motion estimator is used to derive the velocity fields. The results obtained with this self-seeded flow show good agreement with the statistical properties of the 2D turbulent flows reported on the literature.
      PubDate: 2017-04-03
      DOI: 10.1007/s00348-017-2311-4
      Issue No: Vol. 58, No. 5 (2017)
       
  • Positron emission particle tracking in pulsatile flow
    • Authors: Nitant Patel; Cody Wiggins; Arthur Ruggles
      Abstract: Abstract Positron emission particle tracking (PEPT) is increasingly used to understand the flow characteristics in complex systems. This research utilizes PEPT to measure pulsatile flow of frequency 2.1 Hz in an elastic Masterkleer PVC tube of 19 mm inner diameter and 3.2 mm wall thickness. Anion exchange resin beads are labeled with 18F and delivered to a pump driven flow loop with motorized ball valve used to develop the pulsatile flow. Data are collected in the tube with circular cross section, and measurements are also collected with a section of the tube pinched. Nominal flow velocities are near 1 m/s and Reynolds numbers near 20,000. Many thousand PEPT particle traces are collected and synchronized with the flow pulsation. These Lagrangian data are presented as a series of 20 still frames depicting the 3-D velocity field present during each phase of the flow pulsation. Pressure data are also collected to resolve the pressure wave front moving through the open elastic tube at velocity 15.2 m/s.
      PubDate: 2017-04-03
      DOI: 10.1007/s00348-017-2330-1
      Issue No: Vol. 58, No. 5 (2017)
       
  • Weighted divergence correction scheme and its fast implementation
    • Authors: ChengYue Wang; Qi Gao; RunJie Wei; Tian Li; JinJun Wang
      Abstract: Abstract Forcing the experimental volumetric velocity fields to satisfy mass conversation principles has been proved beneficial for improving the quality of measured data. A number of correction methods including the divergence correction scheme (DCS) have been proposed to remove divergence errors from measurement velocity fields. For tomographic particle image velocimetry (TPIV) data, the measurement uncertainty for the velocity component along the light thickness direction is typically much larger than for the other two components. Such biased measurement errors would weaken the performance of traditional correction methods. The paper proposes a variant for the existing DCS by adding weighting coefficients to the three velocity components, named as the weighting DCS (WDCS). The generalized cross validation (GCV) method is employed to choose the suitable weighting coefficients. A fast algorithm for DCS or WDCS is developed, making the correction process significantly low-cost to implement. WDCS has strong advantages when correcting velocity components with biased noise levels. Numerical tests validate the accuracy and efficiency of the fast algorithm, the effectiveness of GCV method, and the advantages of WDCS. Lastly, DCS and WDCS are employed to process experimental velocity fields from the TPIV measurement of a turbulent boundary layer. This shows that WDCS achieves a better performance than DCS in improving some flow statistics.
      PubDate: 2017-04-03
      DOI: 10.1007/s00348-017-2307-0
      Issue No: Vol. 58, No. 5 (2017)
       
 
 
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