Article
Environmental Sciences
Razvan Pirloaga, Mariana Adam, Bogdan Antonescu, Simona Andrei, Sabina Stefan
Summary: For the first time in Romania, Doppler wind lidar measurements were used to analyze wind and turbulence statistics at a peri-urban site in Magurele, southwest of Bucharest. Vertical and scanning measurements from December 2019 to November 2021 were processed, and statistics were performed based on seasonal and diurnal cycles. The results showed variations in diurnal wind speed and direction, with lower speed during the day and higher at night. The ERA5 reanalysis exhibited similar patterns to the Doppler wind lidar measurements, albeit slightly underestimated in terms of wind speed.
Article
Oceanography
Laur Ferris, Donglai Gong, Carol Anne Clayson, Sophia Merrifield, Emily L. Shroyer, Madison Smith, Louis St Laurent
Summary: The ocean surface boundary layer plays a crucial role in energy transfer, and the estimation of turbulence using boundary layer scalings (BLS) has limitations. By utilizing data from autonomous sampling platforms, this study reveals significant discrepancies between measured turbulence and standard shear-convective BLS in different depths and conditions.
JOURNAL OF PHYSICAL OCEANOGRAPHY
(2022)
Article
Meteorology & Atmospheric Sciences
Sicheng Wu, Cristina L. Archer
Summary: The presence of turbine wakes can reduce friction velocity, turbulent kinetic energy, and wind speed near the ground, while turbulent heat flux is not significantly affected. The observed near-ground temperature changes correlate well with the temperature lapse rate between hub height and the ground, with wind speed deficit being the dominant factor influencing surface response.
MONTHLY WEATHER REVIEW
(2021)
Article
Engineering, Civil
Mohammadreza Mataji
Summary: The paper aims to derive an analytical expression for streamwise turbulence intensity (TI) under neutral to unstable stratifications, which can reasonably model TI at heights beyond the atmospheric surface layer (ASL). The proposed models are validated against datasets from four tall meteorological towers, and results show that they reasonably follow the measured velocity variance and TI data under neutral to unstable conditions in the ASL and beyond.
JOURNAL OF WIND ENGINEERING AND INDUSTRIAL AERODYNAMICS
(2022)
Article
Thermodynamics
Dae-Young Kim, Yeon-Hee Kim, Bum-Suk Kim
Summary: This study analyzed the effects of atmospheric stability, turbulence intensity, and wind shear exponent on the power performance and annual energy production of wind turbines. The results showed that atmospheric stability had the greatest impact on AEP, with the highest AEP occurring in moderately unstable atmospheric conditions.
Article
Mechanics
Dinar Zaripov, Vladislav Ivashchenko, Rustam Mullyadzhanov, Renfu Li, Nikolay Mikheev, Christian J. Kaehler
Summary: In this study, the mechanism of near-wall reverse flow (NWRF) events in turbulent duct flow at a relatively low Reynolds number Re-tau around 200 was investigated using direct numerical simulations and particle image velocimetry. A conceptual model was proposed to explain the formation of NWRF events, suggesting they are caused by intense hairpin vortices at the interface between high- and low-momentum flow regions. The similarity of flow topologies associated with NWRF events at Re-tau around 200 with those at higher Reynolds numbers indicates a generality of the proposed mechanism.
JOURNAL OF FLUID MECHANICS
(2021)
Review
Green & Sustainable Science & Technology
C. Perez Albornoz, M. A. Escalante Soberanis, V Ramirez Rivera, M. Rivero
Summary: Wind energy has experienced significant growth, thanks to the development of wind turbines and tall wind masts. Atmospheric stability plays a crucial role in the wind energy industry, impacting wind profile, energy production, and wake effects.
RENEWABLE & SUSTAINABLE ENERGY REVIEWS
(2022)
Article
Mechanics
Yongseok Kwon, Javier Jimenez
Summary: A novel numerical experiment is conducted to isolate the multiscale dynamics of the logarithmic layer of wall-bounded turbulent flows. Despite some differences, the modified flow system reproduces the kinematics and dynamics of natural logarithmic layers well, supporting the idea that the logarithmic layer has its own autonomous dynamics. This suggests that the very large-scale motions of wall-bounded flows are not an intrinsic part of the logarithmic-layer dynamics.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Mechanics
Mitchell Fowler, Tamer A. Zaki, Charles Meneveau
Summary: A large eddy simulation wall model is developed based on a formal interpretation of quasi-equilibrium that governs momentum balance. The model includes a relaxation time scale that ensures self-consistency with assumed quasi-equilibrium conditions. The new approach allows for formally distinguishing between quasi-equilibrium and additional, non-equilibrium contributions to wall stress.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Mechanics
Mitchell Fowler, Tamer A. Zaki, Charles Meneveau
Summary: The recent LaRTE approach is a wall model for large-eddy simulations (LES) that separates equilibrium and non-equilibrium wall-stress dynamics. The model shows good agreement with various non-equilibrium channel flows and provides insights into wall-stress physics.
JOURNAL OF FLUID MECHANICS
(2023)
Article
Mechanics
J. C. Klewicki
Summary: High resolution direct numerical simulation data are used to investigate the similarity solutions for mean velocity and Reynolds shear stress in turbulent channel flow. The analysis yields an invariant form of the mean momentum equation valid over a significant portion of the flow domain. The results provide insights into the development of wall-flow models and support conjectures regarding the behavior of similarity parameters at large Reynolds numbers.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Mechanics
Pierre Ricco, Martin Skote
Summary: The study shows that the Fukagata et al.’s identity simplifies to the von Kaman momentum integral equation for free-stream boundary layers. It is found that the influence of Reynolds stresses on wall-shear stress cannot be quantified for free-stream boundary layers. Analogous identities are found for channel flows, where the laminar and turbulent contributions to the skin-friction coefficient are distinguished. The study also decomposes the skin-friction coefficient into integral thicknesses to quantify the contributions of different terms of the streamwise momentum equation to friction drag.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Environmental Sciences
Melliza Templonuevo Cruz, James Bernard Simpas, Armin Sorooshian, Grace Betito, Maria Obiminda L. Cambaliza, Jarl Tynan Collado, Edwin W. Eloranta, Robert Holz, Xzann Garry Vincent Topacio, Jundy Del Socorro, Gerry Bagtasa
Summary: Fine particulate matter (PM2.5) concentrations in Metro Manila, Philippines consistently exceed WHO guideline values. This study fills the gap in understanding the influence of meteorological factors on PM2.5, specifically the planetary boundary layer height (PBLH). Measurements from a High Spectral Resolution Lidar (HSRL) between January 2019 and June 2020 allowed for PBLH estimation and aerosol typing. Results show that PBLH variability is associated with solar heating and radiative cooling, and lower PM2.5 levels are observed during daytime when PBLH is at its maximum. However, the relationship between PBLH and PM2.5 is only significant during certain months.
ATMOSPHERIC ENVIRONMENT
(2023)
Article
Mechanics
Y. X. Wang, K. -S. Choi, M. Gaster, C. Atkin, V. Borodulin, Y. Kachanov
Summary: The experimental investigation in a low-turbulence wind tunnel revealed that artificially initiated turbulent spots in a laminar boundary layer over a flat plate quickly developed into hairpin-like structures, increasing in width, length and height downstream. Only disturbances greater than a threshold value evolved into turbulent spots, while others decayed. The rate of development was also influenced by the duration of initial disturbances. Additionally, the behavior of turbulence generation within a turbulent spot was found to be similar to burst events in a turbulent boundary layer.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Mechanics
Santhosh B. Mamidala, Andre Weingartner, Jens H. M. Fransson
Summary: To date, there have been very few comparisons between experiments and direct numerical simulations (DNS) on free-stream turbulence (FST) induced boundary layer transition. This is mainly due to the difficulty in carrying out such comparisons because of the large energy gradients and sensitivity to surrounding conditions in transition scenarios. This study presents a detailed comparison between new experiments and available DNS data of a complex FST transition scenario in a flat plate boundary layer. The leading edge pressure gradient distribution and the full energy spectrum at the leading edge are identified as the two most important parameters for a satisfying comparison. The study also defines a measure of FST boundary layer penetration depth using DNS, suggesting that the depth grows with downstream distance and stays around 20% of the boundary layer thickness down to transition onset.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Green & Sustainable Science & Technology
Geng Xia, Caroline Draxl, Ajay Raghavendra, Julie K. Lundquist
Summary: The study investigates the ability of the WRF model to simulate mountain waves and their impact on hub-height wind speed, showing moderate skill in simulating observed mountain waves. The Fast Fourier Transform can calculate the simulated mountain wave impact on wind speed, which agrees well with SoDAR observations in terms of magnitude and pattern. WRF consistently predicts impacts of significant mountain wave events about an hour earlier than actual observations in simulated cases.
Article
Meteorology & Atmospheric Sciences
Alex Rybchuk, Caroline B. Alden, Julie K. Lundquist, Gregory B. Rieker
Summary: The evaluation of the WRF-LES model in this study found that the model accurately simulates surface concentrations under strong convection conditions, but substantially overpredicts concentrations under weak convection. This may be attributed to the model's alignment with local free convection theory and minimal use of parameterized turbulent energy in strong convective conditions.
MONTHLY WEATHER REVIEW
(2021)
Article
Chemistry, Analytical
Elizabeth H. Denis, Kelsey A. Morrison, Sonia Wharton, Shane Phillips, Stephen C. Myers, Michael P. Foxe, Robert G. Ewing
Summary: This study investigated the detection and quantification of intact molecules of high explosive compounds in post-detonation dust, using atmospheric flow tube-mass spectrometry technology. Results showed that the aerial distribution of molecular residue correlated with plume dynamics, which were influenced by wind conditions. The quantity of material detected appeared to be more dependent on distance from the shot and wind conditions rather than shot size.
Review
Agronomy
Manuel Helbig, Tobias Gerken, Eric R. Beamesderfer, Dennis D. Baldocchi, Tirtha Banerjee, Sebastien C. Biraud, William O. J. Brown, Nathaniel A. Brunsell, Elizabeth A. Burakowski, Sean P. Burns, Brian J. Butterworth, W. Stephen Chan, Kenneth J. Davis, Ankur R. Desai, Jose D. Fuentes, David Y. Hollinger, Natascha Kljun, Matthias Mauder, Kimberly A. Novick, John M. Perkins, David A. Rahn, Camilo Rey-Sanchez, Joseph A. Santanello, Russell L. Scott, Bijan Seyednasrollah, Paul C. Stoy, Ryan C. Sullivan, Jordi Vila-Guerau de Arellano, Sonia Wharton, Chuixiang Yi, Andrew D. Richardson
Summary: This review explores how continuous, automated observations of the atmospheric boundary layer can enhance the scientific value of co-located eddy covariance measurements of land-atmosphere fluxes, with four key opportunities highlighted for integrating tower-based flux measurements with continuous atmospheric boundary layer measurements.
AGRICULTURAL AND FOREST METEOROLOGY
(2021)
Article
Meteorology & Atmospheric Sciences
Robert S. Arthur, Timothy W. Juliano, Bianca Adler, Raghavendra Krishnamurthy, Julie K. Lundquist, Branko Kosovic, Pedro A. Jimenez
Summary: In this article, we demonstrate how a new framework for modeling atmospheric turbulence improves cold pool predictions, using a case study from January 2017 in the Columbia River basin (U.S. Pacific Northwest). Cold pools are regions of cold, stagnant air that form within valleys or basins, and improved forecasts could help to mitigate the risks they pose to air quality, transportation, and wind energy production. For the chosen case study, our tests show a reduction in temperature and wind speed errors by up to a factor of 2-3 relative to standard model options. These results strongly motivate continued development of the framework as well as its application to other complex weather events.
JOURNAL OF APPLIED METEOROLOGY AND CLIMATOLOGY
(2022)
Article
Green & Sustainable Science & Technology
Miguel Sanchez Gomez, Julie K. Lundquist, Jeffrey D. Mirocha, Robert S. Arthur, Domingo Munoz-Esparza, Rachel Robey
Summary: Wind plant blockage reduces wind velocity, affecting power generation. The mechanisms and characteristics of the induction zone are not well understood. Field observations and numerical simulations are used to evaluate blockage in an Oklahoma wind plant. The study highlights the challenges of quantifying blockage and the impact of terrain effects.
JOURNAL OF RENEWABLE AND SUSTAINABLE ENERGY
(2022)
Article
Green & Sustainable Science & Technology
Mithu Debnath, Patrick Moriarty, Raghavendra Krishnamurthy, Nicola Bodini, Rob Newsom, Eliot Quon, Julie K. Lundquist, Stefano Letizia, Giacomo Valerio Iungo, Petra Klein
Summary: The American wake experiment (AWAKEN) is being conducted in northern Oklahoma, USA, near the Atmospheric Radiation Measurement Southern Great Plains (ARM SGP) atmospheric observatory. This study analyzes long-term wind data collected at the ARM SGP observatory to characterize the winds near the AWAKEN site. The analysis reveals a high occurrence of wind shear and veer events, especially nocturnal low-level jets, coming predominantly from the south and southeast. By using the Monin-Obukhov similarity theory (MOST) and comparing with observational data, the wind shear at the site can be predicted, with some limitations in the stable boundary layer.
JOURNAL OF RENEWABLE AND SUSTAINABLE ENERGY
(2023)
Article
Meteorology & Atmospheric Sciences
M. Sanchez Gomez, J. K. Lundquist, G. Deskos, S. R. Arwade, A. T. Myers, J. F. Hajjar
Summary: Offshore wind energy deployment in the U.S. is expected to increase in the coming years. However, current wind turbine design criteria may not account for the unique wind characteristics of tropical cyclones. Idealized simulations of five tropical cyclones reveal that wind conditions near the eyewall of Category 1, 2, and 3 storms can exceed current design standards, indicating the need for revised criteria.
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
(2023)
Article
Green & Sustainable Science & Technology
Miguel Sanchez Gomez, Julie K. Lundquist, Jeffrey D. Mirocha, Robert S. Arthur
Summary: Wind plants slow down the approaching wind, causing blockage and reducing the performance of front-row turbines and potentially those deeper into the array. The faster cooling rate at the surface amplifies blockage by producing stronger stably stratified flow in the boundary layer. Evaluating different terms in the momentum conservation equation within the turbine rotor layer helps understand the physical mechanisms amplifying blockage.
WIND ENERGY SCIENCE
(2023)
Article
Green & Sustainable Science & Technology
Paul Veers, Katherine Dykes, Sukanta Basu, Alessandro Bianchini, Andrew Clifton, Peter Green, Hannele Holttinen, Lena Kitzing, Branko Kosovic, Julie K. Lundquist, Johan Meyers, Mark O'Malley, William J. Shaw, Bethany Straw
Summary: Wind power is crucial for transitioning to renewable energy, but faces challenges in design, manufacture, and deployment. The wind research community has made efforts in understanding and addressing these challenges over the past three years.
WIND ENERGY SCIENCE
(2022)
Article
Green & Sustainable Science & Technology
Alex Rybchuk, Timothy W. Juliano, Julie K. Lundquist, David Rosencrans, Nicola Bodini, Mike Optis
Summary: This study compares the sensitivity of wind plant wakes to different boundary layer schemes and finds that the choice of boundary layer scheme affects hub-height wind speeds and capacity factors in wind plants. Therefore, it is recommended to consider the variability of boundary layer schemes in future wind plant planning and wind forecasting studies.
WIND ENERGY SCIENCE
(2022)
Article
Meteorology & Atmospheric Sciences
Rachel Robey, Julie K. Lundquist
Summary: This study investigates the distribution of measurement error due to turbulence in varying atmospheric stability using virtual WindCube V2 lidar simulations. The findings suggest that convective conditions are most prone to large errors, while vector time-averaged measurements can improve the behavior of the error distributions. Systematic analysis of the observation error helps to explain dominant mechanisms and support empirical results.
ATMOSPHERIC MEASUREMENT TECHNIQUES
(2022)
Article
Green & Sustainable Science & Technology
Vincent Pronk, Nicola Bodini, Mike Optis, Julie K. Lundquist, Patrick Moriarty, Caroline Draxl, Avi Purkayastha, Ethan Young
Summary: This study evaluates the performance of ERA-5 and WTK-LED in wind energy prediction. It is found that ERA-5 exhibits a significant negative bias in wind speed simulation, but outperforms WTK-LED in terms of centered root-mean-square error and correlation coefficient. The higher cRMSE of WTK-LED is caused by its tendency to overpredict the amplitude of the wind speed diurnal cycle and its failure to accurately capture wind plant wake effects.
WIND ENERGY SCIENCE
(2022)
Article
Green & Sustainable Science & Technology
Adam S. Wise, James M. T. Neher, Robert S. Arthur, Jeffrey D. Mirocha, Julie K. Lundquist, Fotini K. Chow
Summary: This study investigates the performance and wake behavior of wind turbines under different terrain conditions. The model used in the study is able to accurately simulate the observed behavior of wind turbine wakes. The results show that the wake of the wind turbine is influenced by the terrain and atmospheric stability, leading to different vertical deflections and persistence downstream.
WIND ENERGY SCIENCE
(2022)
Article
Geosciences, Multidisciplinary
Miguel Sanchez Gomez, Julie K. Lundquist, Petra M. Klein, Tyler M. Bell
Summary: The ISARRA hosted a flight week in July 2018 to demonstrate UAS capabilities in sampling the atmospheric boundary layer. Data from Doppler lidars were used to estimate turbulence dissipation rate, showing large temporal variability and significant influence of measurement volume on retrieved values. This dataset has been openly accessible for further research.
EARTH SYSTEM SCIENCE DATA
(2021)