Searched for: subject:"piv"
(1 - 20 of 99)

Pages

document
Engler Faleiros, D. (author)
Particle Image Velocimetry (PIV) relies upon the introduction of particle tracers that scatter sufficient light and follow the flow accurately. The use of submillimetre helium-filled soap bubbles (HFSB) as flow tracers for PIV is investigated for the purpose of enabling velocity measurements in large-scale industrial wind tunnels. That soap...
doctoral thesis 2021
document
Saredi, E. (author), Tumuluru Ramesh, Nikhilesh (author), Sciacchitano, A. (author), Scarano, F. (author)
State observer techniques are investigated for the assimilation of three-dimensional velocity measurements into computational fluid dynamics simulations based on Reynolds-averaged Navier–Stokes (RANS) equations. The method relies on a forcing term, or observer, in the momentum equation, stemming from the difference between the computed velocity...
journal article 2021
document
Guo, Y. (author), Jia, W. (author), Markine, V.L. (author), Jing, Guoqing (author)
Ballast rheology is a phenomenon that describes movements of ballast particles due to the discrete nature, which eventually leads to the ballast bed fluid deformation after a long-time service. In most cases, ballast rheology is the main reason of track irregularity that leads to some track defects, e.g., hanging sleeper and mud spots....
journal article 2021
document
Terra, W. (author)
The use of large-scale particle image velocimetry (PIV) is proposed for cycling aerodynamic study to advance the general understanding of the flow around the rider and the bike, leading to new strategies for cycling aerodynamic drag reduction in the future. The investigation concentrates on the measurement of the wake velocity and its relation...
doctoral thesis 2020
document
Melani, P. F. (author), Balduzzi, F. (author), Brandetti, L. (author), Ferreira, Carlos (author), Bianchini, A. (author)
Simulation methods ensuring a level of fidelity higher than that of the ubiquitous Blade Element Momentum theory are increasingly applied to VAWTs, ranging from Lifting-Line methods, to Actuator Line or Computational Fluid Dynamics (CFD). The inherent complexity of these machines, characterised by a continuous variation of the angle of attack...
journal article 2020
document
Jacobi, G. (author)
As soon a ship operates at high forward speeds its weight is pre-dominantly supported by hydrodynamic, rather than hydrostatic forces. Small changes in the dynamic pressure distribution on the ship hull can have a significant influence on the ship’s running attitude in calm water, but also on its seakeeping performance. In order to further...
doctoral thesis 2020
document
Duinmeijer, S.P.A. (author)
This is an experimental and theoretical research on the motion of buoyant particles in the flow of a free-surface vortex at moderate to high particle Reynolds numbers.
doctoral thesis 2020
document
Thota Radhakrishnan, A.K. (author), Poelma, C. (author), van Lier, J.B. (author), Clemens, F.H.L.R. (author)
Transition from laminar to turbulent flow of non-Newtonian fluids is investigated using velocimetry data. These data are obtained by applying particle image velocimetry to images obtained through ultrasound imaging (echography). This yielded the observation of intermittent structures (puffs and slugs) that are formed during transition. Post...
journal article 2020
document
Rietveld, M.W.J. (author), de Rijke, D. (author), Langeveld, J.G. (author), Clemens, F.H.L.R. (author)
Urban runoff (re)mobilises solids present on the street surface and transport them to urban drainage systems. The solids reduce the hydraulic capacity of the drainage system due to sedimentation and on the quality of receiving water bodies due to discharges via outfalls and combined sewer overflows (CSOs) of solids and associated pollutants....
journal article 2020
document
Rezaeiha, Abdolrahim (author), Kotsonis, M. (author)
Wind tunnel measurements are performed to investigate the potential for mitigation of aerodynamic load fluctuations on airfoils, as the main source of fatigue for wind turbines, using plasma actuators. The experiment consists of aerodynamic force measurements using six strain gauges and 2-component velocity measurements using particle image...
journal article 2020
document
Voorneveld, J.D. (author), Saaid, H. (author), Schinkel, C.V. (author), Radeljic, Nikola (author), Lippe, Boris (author), Gijsen, F.J.H. (author), van der Steen, A.F.W. (author), de Jong, N. (author), Claessens, T.P.T. (author), Vos, H.J. (author), Kenjeres, S. (author), Bosch, Johan G. (author)
Left ventricular (LV) blood flow is an inherently complex time-varying 3-D phenomenon, where 2-D quantification often ignores the effect of out-of-plane motion. In this study, we describe high frame rate 4-D echocardiographic particle image velocimetry (echo-PIV) using a prototype matrix transesophageal transducer and a dynamic LV phantom for...
journal article 2020
document
Spoelstra, A.M.C.M.G. (author), Hirsch, Maximilian (author), Sciacchitano, A. (author), Scarano, F. (author)
The Ring of Fire (RoF) measurement concept to perform on-site experiments of aerodynamic drag for transiting objects is investigated with a study that identifies the main sources of uncertainty. The main contributors to the uncertainty of the drag measurement are examined for the case of a cyclist riding through the measurement domain. A...
journal article 2020
document
Scharnowski, S. (author), Sciacchitano, A. (author), Kahler, Christian J. (author)
For the reliable estimation of velocity vector fields by means of particle image velocimetry (PIV), the cross-correlation functions calculated from the signal within each interrogation window must feature a distinct peak that represents the average shift of the particle image ensemble. A high valid detection probability (VDP) of the correct...
journal article 2019
document
Saaid, Hicham (author), Voorneveld, Jason (author), Schinkel, C.V. (author), Westenberg, Jos (author), Gijsen, F.J.H. (author), Segers, Patrick (author), Verdonck, Pascal (author), de Jong, N. (author), Kenjeres, S. (author)
Left ventricular flow is intrinsically complex, three-dimensional and unsteady. Its features are susceptible to cardiovascular pathology and treatment, in particular to surgical interventions involving the valves (mitral valve replacement). To improve our understanding of intraventricular fluid mechanics and the impact of various types of...
journal article 2019
document
Haidari, A.H. (author), Heijman, Sebastiaan (author), Uijttewaal, W.S.J. (author), van der Meer, W.G.J. (author)
Feed spacer orientation affects the velocity pattern and pressure drop of spacer-filled channels such as those encountered in Spiral-wound Membrane (SWM) modules of Reverse Osmosis (RO). However, there are only limited numbers of experimental studies on this topic. This study sets out to reveal more detailed information on the pressure drop...
journal article 2019
document
Dulin, V. M. (author), Lobasov, A. S. (author), Chikishev, L. M. (author), Markovich, D. M. (author), Hanjalic, K. (author)
We report on a study of the impact of coherent helical vortex structures on the shape of the reaction zone and heat release in swirling methane/air flames in regimes with a vortex breakdown. Three kinds of atmospheric flames are considered, viz., fuel-lean and fuel-rich premixed flames and a partially premixed fuel-rich lifted flame. Based on...
journal article 2019
document
Timoshevskiy, Mikhail V. (author), Pervunin, Konstantin S. (author), Markovich, Dmitriy M. (author), Hanjalic, K. (author)
We studied cavitating flow over the suction side of a symmetric 2D foil - a scaled-down model of high-pressure hydroturbine guide vanes (GV) - in different cavitation regimes at several attack angles. High-speed imaging was used to analyze spatial patterns and time dynamics of the gas-vapor cavities, as well as for evaluating the...
conference paper 2019
document
Casacuberta Puig, J. (author), Groot, K.J. (author), Ye, Q. (author), Hickel, S. (author)
Micro-ramps are popular passive flow control devices which can delay flow separation by re-energising the lower portion of the boundary layer. We compute the laminar base flow, the instantaneous transitional flow, and the mean flow around a micro-ramp immersed in a quasi-incompressible boundary layer at supercritical roughness Reynolds number...
journal article 2019
document
Adam, Florian (author), Terra, W. (author), Sciacchitano, A. (author)
Large-scale particle image velocimetry (PIV) is used to characterize the dynamics of the unsteady wake of a non-pedalling full-scale cyclist. This to provide better understanding of the flow structures that generate the aerodynamic drag. Instantaneous flow fields are acquired and averaged to obtain the time-average flow topology. Afterwards,...
journal article 2019
document
Guo, Y. (author), Markine, V.L. (author), Zhang, X. (author), Qiang, Weile (author), Jing, Guoquig (author)
The performance and deformation of ballast bed are significantly influenced by the particle morphology (size and shape), the rheology (translation and rotation), and the degradation (breakage and abrasion). Regarding the ballast particle morphology, the ballast particle size is generally measured by sieving and described with the Particle Size...
review 2019
Searched for: subject:"piv"
(1 - 20 of 99)

Pages