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A multi-site, year-round turbulence microstructure atlas for the deep perialpine Lake Garda

Sebastiano Piccolroaz, Bieito Fernández-Castro, Marco Toffolon, Henk A. Dijkstra
2021 Scientific Data  
Turbulence quantities were estimated, quality-checked, and merged with water quality and meteorological data to produce a unique turbulence atlas for a lake.  ...  The dataset is open to a wide range of possible applications, including research on the variability of turbulent mixing across seasons and sites (demersal vs pelagic zones) and driven by different factors  ...  The percentage of estimates that are scattered within a factor of 2.8 and 10 are reported in the corresponding panels, along with the coefficient of determination R 2 of a linear regression model.  ... 
doi:10.1038/s41597-021-00965-0 pmid:34294730 pmcid:PMC8298655 fatcat:35k4iwalpzhp3jw7llr73ya2cy

Modelling the spectral shape of continuous-wave lidar measurements in a turbulent wind tunnel

Marijn Floris van Dooren, Anantha Padmanabhan Kidambi Sekar, Lars Neuhaus, Torben Mikkelsen, Michael Hölling, Martin Kühn
2022 Atmospheric Measurement Techniques  
a simple model based on the full width at half maximum (FWHM) of the laser beam intensity along the line of sight and assuming Taylor's frozen turbulence hypothesis.  ...  Larger flow structures can be captured more accurately by the lidar, whereas small-scale turbulent flow structures are partly filtered out as a result of the lidar's probe volume averaging effect.  ...  Lastly we would like to thank Mikael Sjöholm and Claus Brian Munk Pedersen from the Technical University of Denmark for their invaluable remote assistance with troubleshooting WindScanner hardware-and  ... 
doi:10.5194/amt-15-1355-2022 fatcat:siyuuxghuve2tmjbe5eqji7vky

Odor transport in turbulent flows: Constraints on animal navigation

Christopher M. Finelli, N. Dean Pentcheff, Richard K. Zimmer-Faust, David S. Wethey
1999 Limnology and Oceanography  
In addition, certain characteristics of individual odor filaments may vary consistently with distance from the odor source, thus providing directional information to a navigating organism.  ...  Here, we present the results of a field study during which we measured the distributions of the time-averaged concentration, properties of odor filaments, conditional statistics, and relevant hydrodynamic  ...  Acknowledgments We thank Dennis Allen and the rest of the Baruch Staff for providing facilities and logistic support for this project. J. E. Eckman, T. J. Hilbish, P. A. Jumars, S. A.  ... 
doi:10.4319/lo.1999.44.4.1056 fatcat:w7u7fwm6sbfmjpxheuarhmdsyu

Non-invasive estimation of relative pressure in turbulent flow using virtual work-energy

David Marlevi, Hojin Ha, Desmond Dillon-Murphy, Joao F. Fernandes, Daniel Fovargue, Massimiliano Colarieti-Tosti, Matilda Larsson, Pablo Lamata, C. Alberto Figueroa, Tino Ebbers, David A. Nordsletten
2019 Medical Image Analysis  
Recently, we proposed a novel method for non-turbulent flows, νWERP, utilizing the concept of virtual work-energy to accurately probe relative pressure through complex branching vasculature.  ...  We present a theoretical method derivation based on flow covariance, quantifying the impact of flow fluctuations on relative pressure. νWERP-t is tested on a set of in-vitro stenotic flow phantoms with  ...  Ground truth relative pressures given by the solid gray line, with corresponding estimates given by the dashed black line with black dots.  ... 
doi:10.1016/ pmid:31865280 fatcat:chzu6ipr75b2hb6fc5cxe2tera

Lyapunov exponent as a metric for assessing the dynamic content and predictability of large-eddy simulations

Gabriel Nastac, Jeffrey W. Labahn, Luca Magri, Matthias Ihme
2017 Physical Review Fluids  
This metric is applied to two turbulent flow configurations: forced homogeneous isotropic turbulence and a turbulent jet diffusion flame.  ...  By comparing inert and reacting flows, it is shown that combustion increases the predictability of the turbulent simulation as a result of the dilatation and increased viscosity by heat release.  ...  Computational resources supporting this work were provided by the National Energy Research Scientific Computing Center, a DOE Office of Science User Facility supported by the Office of Science of the US  ... 
doi:10.1103/physrevfluids.2.094606 fatcat:exlg5bjdobhkbghkzimheqecda

An efficient surrogate model for emulation and physics extraction of large eddy simulations [article]

Simon Mak, Chih-Li Sung, Xingjian Wang, Shiang-Ting Yeh, Yu-Hung Chang, V. Roshan Joseph, Vigor Yang, C. F. Jeff Wu
2017 arXiv   pre-print
In this paper, we propose a new surrogate model that provides efficient prediction and uncertainty quantification of turbulent flows in swirl injectors with varying geometries, devices commonly used in  ...  In the quest for advanced propulsion and power-generation systems, high-fidelity simulations are too computationally expensive to survey the desired design space, and a new design methodology is needed  ...  This splits the flow in such a way that the linearity assumption can be physically justified. as the L-BFGS map for a single line-search when optimizing µ and τ with T fixed.  ... 
arXiv:1611.07911v2 fatcat:o5ncwrn7azd7peyzg5delugpo4

Controls on eDNA movement in streams: Transport, Retention, and Resuspension

Arial J. Shogren, Jennifer L. Tank, Elizabeth Andruszkiewicz, Brett Olds, Andrew R. Mahon, Christopher L. Jerde, Diogo Bolster
2017 Scientific Reports  
In reality, streams are complex, reactive systems, with rapid, turbulent flows connected to slower flows in the subsurface and near-surface streambed 1 .  ...  and estimating biodiversity.  ...  Mecca, and A. Geissler for assistance with sample collection, and M. Renshaw, C. Gantz, K. Uy, for assistance processing eDNA samples.  ... 
doi:10.1038/s41598-017-05223-1 pmid:28698557 pmcid:PMC5506058 fatcat:w477nngrdfbhpca7jsnev7uf64

Turbulence-mediated facilitation of resource uptake in patchy stream macrophytes

Loreta Cornacchia, Sofia Licci, Heidi Nepf, Andrew Folkard, Daphne van der Wal, Johan van de Koppel, Sara Puijalon, Tjeerd J. Bouma
2018 Limnology and Oceanography  
Black lines 657 are linear regression lines for the Groenlandia (solid line) and Callitriche (dotted line) data separately 658 and represent significant relationships (p  0.05).  ...  Black lines 708 are linear regression lines for the Groenlandia (solid line) and Callitriche (dotted line) data separately 709 and represent significant relationships (p  0.05).  ... 
doi:10.1002/lno.11070 fatcat:hxhnd6lxzbff3bhm4yhyeniz5u

Perspectives on SCADA Data Analysis Methods for Multivariate Wind Turbine Power Curve Modeling

Davide Astolfi
2021 Machines  
The rationale for a multivariate approach to wind turbine power curve is the potential decrease of the error metrics of the regression: this allows monitoring the performance of the target wind turbine  ...  In this regard, a promising line of research regards multivariate approaches to the wind turbine power curve: these are based on incorporating additional environmental information or working parameters  ...  Conflicts of Interest: The author declares no conflict of interest. Abbreviations The following abbreviations are used in this manuscript:  ... 
doi:10.3390/machines9050100 fatcat:d2tyviqupbb75mxhc5jefjvn7y

The effects of cylindrical surface modifications on turbulent boundary layers

1986 AIAA Journal  
Two Starrett micrometers provided a maximum probe traverse of 50 mm, with a resolution of 0.01 mm, in both the streamwise and transverse flow directions.  ...  In contrast, for a flat plate flow, fluid. inflows and streak interactions primarily result in lateral movement of the whole streak.  ... 
doi:10.2514/3.9395 fatcat:cnwc23jdbbb6jdqh75nftwvqdy

Calculating the Explicit Probability of Entrainment Based on Inertial Acceleration Measurements

Georgios Maniatis, Trevor B. Hoey, Marwan A. Hassan, Joseph Sventek, Rebecca Hodge, Tim Drysdale, Manousos Valyrakis
2017 Journal of Hydraulic Engineering  
for entrainment of large grains in turbulent flows is less 180 than the frequency for characterising flow turbulence due to the lower sensitivity of particle 181 movement to micro-turbulence.  ...  )) and turbulence (e.g.  ... 
doi:10.1061/(asce)hy.1943-7900.0001262 fatcat:f2eutc5xybb3rfzqduq7daqa2a

Measurement of 3D bubble distribution using digital inline holography [article]

Siyao Shao, Jiarong Hong
2019 arXiv   pre-print
Overall, our paper introduces a low cost, compact and high-resolution bubble measurement technique that can be used for characterizing low void fraction bubbly flow in a broad range of applications.  ...  In contrast, a large bubble/cluster is segmented using a modified watershed segmentation algorithm and its depth is measured through a wavelet-based focus metric.  ...  Subsequently, the slope of the linear regression line derived from ( ) vs plot is used to estimate the bubble inclination angle α with respect to the s.  ... 
arXiv:1904.10894v1 fatcat:d3ro647w7vhjrdrveb3swmj6nq

Swimming performance of upstream migrant fishes in open-channel flow: a new approach to predicting passage through velocity barriers

Alex Haro, Theodore Castro-Santos, John Noreika, Mufeed Odeh
2004 Canadian Journal of Fisheries and Aquatic Sciences  
David Hosmer and Mike Sutherland provided guidance on  ...  The Froude number, F; which equals the ralio of lhcse two forces, identifies the state of flow: where g is gravitational acceleration and L is lhc depth of flow in a channel with a rectangular cross scction  ...  Vol. 61, 2004 squares regression, with scalc (0) and shape (8) parameters that influence the valuc of w,.  ... 
doi:10.1139/f04-093 fatcat:icv6vr56nragrbbm6rslgrow2y

Probabilistic estimation of the Dynamic Wake Meandering model parameters using SpinnerLidar-derived wake characteristics

Davide Conti, Nikolay Dimitrov, Alfredo Peña, Thomas Herges
2021 Wind Energy Science  
We then apply Bayesian inference to obtain a probabilistic calibration of the DWM model, where the resulting joint distribution of parameters allows for both model implementation and uncertainty assessment  ...  We derive two-dimensional wake flow characteristics including wake deficit, wake turbulence, and wake meandering from the lidar observations under different atmospheric stability conditions, inflow wind  ...  Sandia National Laboratories is a multimission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International, Inc  ... 
doi:10.5194/wes-6-1117-2021 fatcat:e2yfciiepndotho6af2sn2ihp4

Forced and unforced unsteadiness in an axial turbomachine

Jesús Manuel Fernández Oro, Eduardo Blanco Marigorta, Katia María Argüelles Díaz, Rafael Ballesteros-Tajadura
2009 Experimental Thermal and Fluid Science  
It is shown that the turbulent kinetic energy reaches up to approximately a 50-60% of the total unsteady energy, while both forced and unforced components contribute equally to the rest of the energy.  ...  It is demonstrated that the estimation of the unforced unsteadiness constitutes an accurate indicator of the presence of tip leakage flows for axial turbomachinery.  ...  ACKNOWLEDGEMENTS This work was supported by the Research Project "Characterization of the Generation of Aerodynamic Noise due to the Interaction between the Rotor Blades and the Guide Vanes in Axial Flow  ... 
doi:10.1016/j.expthermflusci.2008.10.012 fatcat:xhxb3g3g6fdilkdpzajrjizziq
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