Article
Mechanics
Ling-xin Zhang, Xin-sheng Cheng, Ze-cai Zhou, Qi Gao, Xue-ming Shao
Summary: In this study, we conducted a series of experiments to investigate the velocity fluctuations caused by the flow past fixed spheres. The results show that the fluctuations can be classified into temporal fluctuations and spatial fluctuations, representing the contributions of flow instability and spatial inhomogeneity, respectively. At low Reynolds numbers, the total fluctuation is mainly caused by the spatial fluctuation, while at higher Reynolds numbers, both flow instability and spatial inhomogeneity contribute to the total velocity fluctuation. Moreover, the energy distribution and wavenumber spectra of the fluctuations also change significantly with the increase of Reynolds number.
JOURNAL OF HYDRODYNAMICS
(2022)
Article
Thermodynamics
Iacopo Tirelli, Andrea Ianiro, Stefano Discetti
Summary: Particle Image Velocimetry (PIV) estimates velocities through particle image correlations, which leads to a modulation effect. To exploit the scattered data from Particle Tracking Velocimetry (PTV), interpolation on a structured grid is necessary, causing spatial modulation bias. A technique called Ensemble Particle Tracking Velocimetry (EPTV) is introduced to reduce this systematic error by merging different instantaneous realizations and obtaining high-resolution mean flow. The methodology is validated against various datasets with increasing complexity, using PTV and PIV analysis.
EXPERIMENTAL THERMAL AND FLUID SCIENCE
(2023)
Article
Multidisciplinary Sciences
David M. Durieux, Kevin T. Du Clos, David B. Lewis, Brad J. Gemmell
Summary: The upside-down jellyfish Cassiopea sp. plays a significant role in water column mixing within its shallow natural habitat; it continuously pumps water vertically to create a significant contribution to mixing, resulting in turnover of the water column every 15 minutes at median population density. Additionally, the release of nutrient-rich benthic porewater further emphasizes Cassiopea sp.'s role as an ecosystem engineer in mangrove habitats.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Mechanics
S. Beetham, R. O. Fox, J. Capecelatro
Summary: In this study, model closures for multiphase Reynolds-averaged Navier-Stokes (RANS) equations are developed using sparse regression and Eulerian-Lagrangian simulations to ensure accuracy and robustness of the models across different flow conditions. The focus is on capturing the dynamics of gas-particle flows, particularly the generation of particle clusters and interphase momentum exchange, in a compact and algebraic manner.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Engineering, Aerospace
Kyle Twarog, Ossama Mannaa, Chih-Jen Sung, Hukam C. Mongia
Summary: Success in developing advanced combustor concepts relies on achieving rapid and uniform mixing of fuel and combustion air, detailed understanding of the flow characteristics of key mixers is essential to guide the design and development of gas turbine combustors. Leveraged recent advances in CFD and diagnostic techniques, a series of studies have initiated to develop best practices on integrated experimentation and simulation for two families of mixers.
AEROSPACE SCIENCE AND TECHNOLOGY
(2021)
Article
Engineering, Environmental
Justin Weber, Jonathan E. Higham, Jordan Musser, William D. Fullmer
Summary: This study focuses on quantifying the visible depth of field in a dense fluidized bed by extracting particle velocity from simulated data and high-speed videos, comparing the errors of different particle tracking methods. The results show that at a depth of one particle diameter, all three tracking codes provide accurate measurements, but errors increase when looking at full bed video measurements.
CHEMICAL ENGINEERING JOURNAL
(2021)
Article
Mechanics
Ojing Siram, Sachin Y. Shinde, Vinayak Kulkarni, Niranjan Sahoo
Summary: The behavior of wind turbine wake is unique and carries crucial information on the nature of wake propagation. In this study, a stereo particle image velocimetry (SPIV) technique is used to map and assess the flow field behind a model horizontal-axis wind turbine under low tip speed ratio conditions. The results provide a better understanding of the helical behavior of the wake and its relationship with the velocity deficit.
Article
Mechanics
Naveen Rohilla, Partha S. Goswami
Summary: This article explores the variation of local isotropy of fluid fluctuations and the decrease of the Kolmogorov constant in particle-laden turbulent channel flows. The author also adopts a new modeling technique using large-eddy simulation (LES) to predict fluid phase statistics without solving simultaneous particle phase equations. This study provides insights into the phenomena of drastic collapse in turbulence intensity.
JOURNAL OF FLUID MECHANICS
(2023)
Article
Mechanics
Yan Xia, Zhaosheng Yu, Zhaowu Lin, Yu Guo
Summary: This study establishes correlations between the interfacial terms and the fluid dissipation rate equation and Reynolds stress equations in particle-laden flows, providing an accurate mathematical model and method for simulating particle-induced turbulence.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Engineering, Multidisciplinary
Yaofa Li, Gianluca Blois, Farzan Kazemifar, Kenneth T. Christensen
Summary: This paper presents a novel method for robust phase separation and phase boundary identification through PIV-acquired particle images, based on particle detection and triangular meshing.
MEASUREMENT SCIENCE AND TECHNOLOGY
(2021)
Article
Environmental Sciences
Seth A. Schweitzer, Edwin A. Cowen
Summary: This paper introduces a new method called Infrared Quantitative Image Velocimetry (IR-QIV) for high-resolution real-time calculation of velocity fields over large water bodies under most weather conditions, with results showing agreement with acoustic velocity measurements, improving both fixed and mobile platform velocimetry.
WATER RESOURCES RESEARCH
(2021)
Article
Thermodynamics
Sai Sandeep Dammati, Yoram Kozak, Cal Rising, Jonathan Reyes, Kareem A. Ahmed, Alexei Y. Poludnenko
Summary: Numerical investigation was conducted on the accuracy of Particle Image Velocimetry (PIV) technique in high-speed, compressible gas-phase detonations, showing minimal impact of massive particles on flow characteristics and better sampling ability of 50 nm particles, although clustering was observed. The study also revealed that PIV is generally capable of capturing bulk flow features in the streamwise direction but lacks accuracy in characterizing transverse velocity components or fluctuations.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2021)
Article
Chemistry, Analytical
Giovanni Marinaro, Christian Riekel, Francesco Gentile
Summary: Aqueous solution droplets can be support quasi contact-free by superhydrophobic surfaces, allowing manipulation and control of biological molecules. Using particle image velocimetry, researchers studied the flow field of water droplets containing polystyrene particles on a super-hydrophobic chip, observing vortex-like motions of particles around the droplet center. The characteristics of the internal flow can be modulated by varying the intensity of the temperature gradient along the drop, influencing how particles are transported based on their size.
Article
Environmental Sciences
A. Shirinzad, S. Kumahor, M. F. Tachie, H. Ghamry, C. Katopodis
Summary: Dams and other flow control structures create obstacles for fish migration, which can have negative impacts on aquatic habitats and fish populations. Providing effective passage for fish over hydroelectric dams is essential for restoring habitat connectivity. This study experimentally investigates the hydrodynamic conditions necessary for promoting downstream fish migration over spillways. The results suggest that modifying spillway designs can improve the passage efficiency and create more suitable conditions for downstream migrants.
RIVER RESEARCH AND APPLICATIONS
(2023)
Article
Engineering, Mechanical
Muhsin Can Akkurt, Marco Virgilio, Tony Arts, Kevin Van Geem, Delphine Laboureur
Summary: This study aims to accurately determine the velocity field of turbulent flow in an optically complex-shaped obstacle channel using a ray tracing-based image correction method. The method effectively eliminates high-level image distortions caused by heart-shaped dimples in PIV images. An optimization algorithm and artificial image recreation are used to reduce uncertainties in the application of the method. Experimental results show that the highest levels of turbulent kinetic energy are found downstream of the heart-shaped dimples, indicating the best heat transfer location.
EXPERIMENTS IN FLUIDS
(2022)
Article
Pharmacology & Pharmacy
I. Pasquali, C. Merusi, G. Brambilla, E. J. Long, G. K. Hargrave, H. K. Versteeg
INTERNATIONAL JOURNAL OF PHARMACEUTICS
(2015)
Article
Engineering, Mechanical
Matthew C. Parker, Graham K. Hargrave
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART P-JOURNAL OF SPORTS ENGINEERING AND TECHNOLOGY
(2016)
Article
Engineering, Mechanical
B. A. Reid, M. Gavaises, N. Mitroglou, G. K. Hargrave, C. P. Garner, E. J. Long, R. M. McDavid
EXPERIMENTS IN FLUIDS
(2014)
Article
Thermodynamics
Edward James Long, Graham K. Hargrave
FLOW TURBULENCE AND COMBUSTION
(2011)
Article
Thermodynamics
Ben A. Reid, Graham K. Hargrave, Colin P. Garner, Robert M. McDavid
INTERNATIONAL JOURNAL OF ENGINE RESEARCH
(2013)
Article
Chemistry, Physical
V. Di Sarli, A. Di Benedetto, E. J. Long, G. K. Hargrave
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2012)
Article
Geosciences, Multidisciplinary
James R. Cooper, John Wainwright, Anthony J. Parsons, Yuichi Onda, Tomomi Fukuwara, Eiichiro Obana, Ben Kitchener, Edward J. Long, Graham H. Hargrave
JOURNAL OF GEOPHYSICAL RESEARCH-EARTH SURFACE
(2012)
Article
Physics, Fluids & Plasmas
Edward J. Long, Graham K. Hargrave, James R. Cooper, Ben G. B. Kitchener, Anthony J. Parsons, Caspar J. M. Hewett, John Wainwright
Article
Mechanics
B. A. Reid, G. K. Hargrave, C. P. Garner, G. Wigley
Article
Engineering, Chemical
B. Gavtash, H. K. Versteeg, G. Hargrave, B. Myatt, D. Lewis, T. Church, G. Brambilla
AEROSOL SCIENCE AND TECHNOLOGY
(2017)
Article
Engineering, Chemical
B. Gavtash, H. K. Versteeg, G. Hargrave, B. Myatt, D. Lewis, T. Church, G. Brambilla
AEROSOL SCIENCE AND TECHNOLOGY
(2017)
Proceedings Paper
Physics, Applied
B. A. Reid, M. Gavaises, N. Mitroglou, G. K. Hargrave, C. P. Garner, R. M. McDavid
9TH INTERNATIONAL SYMPOSIUM ON CAVITATION (CAV2015)
(2015)
Article
Transportation Science & Technology
Paul Gaynor, Benjamin Reid, Graham Hargrave, Thomas Lockyer, Jonathan Wilson
SAE INTERNATIONAL JOURNAL OF ENGINES
(2015)
Article
Transportation Science & Technology
Petros Efthymiou, Martin H. Davy, Colin P. Garner, Graham K. Hargrave, John E. T. Rimmer, Dave Richardson
SAE INTERNATIONAL JOURNAL OF ENGINES
(2013)
Article
Transportation Science & Technology
Benjamin T. Johnson, Graham K. Hargrave, Benjamin Reid, Vivian J. Page
SAE INTERNATIONAL JOURNAL OF ENGINES
(2011)
Article
Engineering, Chemical
Andrea Coletto, Pietro Poesio
Summary: Experiments and simulations were conducted to study the air volume fraction and hold-up in a bubble channel reactor. A new signal processing method was proposed to avoid the loss of bubble residence time. The results were in agreement with previous studies and a bubble-scale model was developed to explain the relationship between hold-up and air superficial velocity.
CHEMICAL ENGINEERING RESEARCH & DESIGN
(2024)