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Grille Guerra, A. (author), Scarano, F. (author), Sciacchitano, A. (author)The scalability of experiments using PIV relies upon several parameters, namely illumination power, camera sensor and primarily the tracers light scattering capability. Given their larger cross section, helium-filled soap bubbles (HFSB) allow measurements in air flows over a significantly large domain compared to traditional oil or fog droplets....journal article 2024
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Hysa, I. (author), Tuinstra, Marthijn (author), Sciacchitano, A. (author), Scarano, F. (author), Schwartz, Nicholas (author), Harrison, Charles (author), Gebbink, Roy (author)Volumetric particle tracking velocimetry measurements are performed in a low-speed wind tunnel to study the flow around a 1:12-scale aircraft model with jet engines operating with thrust reversers. The engine jet and freestream flow velocity are varied to yield a jet to freestream velocity ratio of V<sub>jet</sub>/V<sub>∞</sub> ranging from 1...journal article 2023
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Jux, C. (author), Sciacchitano, A. (author), Scarano, F. (author)The aerodynamic characteristics of a modern road cycling wheel in cross wind are studied through force- and planar PIV measurements in the TU Delft Open Jet Facility. The performance of the 62 mm deep rim is evaluated for three tire profiles, and yaw angles up to 24°. All measurements are executed at 12.5 m/s (45 km/h) freestream- and wheel...journal article 2023
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Huang, M. (author), Ferreira, Carlos (author), Sciacchitano, A. (author), Scarano, F. (author)The wake recovery from planar porous actuators that surrogate the effect of wind turbines is investigated, focusing on rectangular shapes for vertical axis wind turbines (VAWTs). We proposed an effective mixing diameter D∗ to scale the streamwise momentum recovery for actuators of arbitrary shape. The length-scale D∗ is given by the ratio...journal article 2022
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Scarano, F. (author), Schneiders, J.F.G. (author), Gonzalez Saiz, G. (author), Sciacchitano, A. (author)The vortex-in-cell time-segment assimilation (VIC-TSA) method is introduced. A particle track is obtained from a finite number of successive time samples of the tracer’s position and velocity can be used for reconstruction on a Cartesian grid. Similar to the VIC + technique, the method makes use of the vortex-in-cell paradigm to produce...journal article 2022
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Hysa, I. (author), Tuinstra, Marthijn (author), Lammers, K (author), Scarano, F. (author), Sciacchitano, A. (author), Gebbink, Roy (author), Harrison, C (author)Volumetric PIV measurements are performed to study the flow development around a 1:12 scale model of a thrust reverser in a low-speed wind tunnel. The thrust-reverser operates in a freestream flow of 3-5 m/s and with a jet to freestream velocity ratio Vjet/Vinf ranging from 1.5 to 6. Making use of sub-millimeter helium-filled soap bubbles, large...conference paper 2022
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Saredi, E. (author), Sciacchitano, A. (author), Scarano, F. (author)The occurrence of data outliers in PIV measurements remains nowadays a problematic issue; their effective detection is relevant to the reliability of PIV experiments. This study proposes a novel approach to outliers detection from time-averaged three-dimensional PIV data. The principle is based on the agreement of the measured data to the...journal article 2022
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Gonzalez Saiz, G. (author), Sciacchitano, A. (author), Scarano, F. (author)An experimental methodology is proposed to study aeroelastic systems with optical diagnostics. The approach locally evaluates the three physical mechanisms that produce the forces involved in Collar’s triangle, namely aerodynamic, elastic, and inertial forces. Flow and object surface tracers are tracked by a volumetric particle image...journal article 2022
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Jux, C. (author), Sciacchitano, A. (author), Scarano, F. (author)The aerodynamic characteristics of a modern road cycling wheel in crosswind are studied through force measurements and 3D velocimetry in TU Delft’s Open Jet Facility. The performance of the 62 mm deep rim is evaluated for two tire profiles, and yaw angles up to 20◦ . All measurements are executed at 12.5 m/s (45 km/h) freestream- and wheel...conference paper 2021
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Scarano, F. (author), Jux, C. (author), Sciacchitano, A. (author)The present work reviews the recent developments in the domain of particle image velocimetry (PIV) with attention to its use for large-scale problems of interest for industrial aerodynamics. The article introduces the fundamental principles of flow seeding for large-scale experiments based on the helium-filled soap bubble (HFSB) technique....journal article 2021
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Engler Faleiros, D. (author), Tuinstra, Marthijn (author), Sciacchitano, A. (author), Scarano, F. (author)The behaviour of nearly neutrally buoyant tracers is studied by means of experiments with helium-filled soap bubbles and numerical simulations. The current models used for estimating the slip velocity of heavy micro particles and neutrally buoyant particles are reviewed and extended to include the effect of unsteady forces and particle...journal article 2021
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Spoelstra, A.M.C.M.G. (author), Sciacchitano, A. (author), Scarano, F. (author), Mahalingesh, Nikhil (author)The aerodynamic drag of a trailing cyclists in a tandem formation is investigated at different lateral and longitudinal separations. A Ring of Fire (RoF) experiment is conducted at the Tom Dumoulin bike park of Sittard-Geleen in the Netherlands. The method is based on stereoscopic Particle Image Velocimetry (Stereo-PIV) measurements followed...journal article 2021
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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
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Jux, C. (author), Sciacchitano, A. (author), Scarano, F. (author)Abstract: A method to identify the surface of solid models immersed in fluid flows is devised that examines the spatial distribution of flow tracers. The fluid–solid interface is associated with the distance from the center of a circle to the centroid of the tracers ensemble captured within it. The theoretical foundation of the method is...journal article 2021
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Jux, C. (author), Sciacchitano, A. (author), Scarano, F. (author)An experimental approach for the measurement of the time-average fluid flow pressure over the surface of generic three-dimensional objects is presented. The method is based on robotic volumetric PTV measurements followed by the integration of the pressure gradient. The domain for pressure evaluation is subdivided in two parts: in the...journal article 2020
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Terra, W. (author), Sciacchitano, A. (author), Scarano, F. (author)The Reynolds number effects on body limbs of a cyclist model, namely leg and arm, are investigated via robotic volumetric Particle Image Velocimetry measurements in the velocity range from 5 m/s to 25 m/s. The near wakes of such body limbs feature recirculation regions whose width and length are governed not only by the taper of the body...journal article 2020
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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
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Saredi, E. (author), Sciacchitano, A. (author), Scarano, F. (author)A novel approach is investigated to extend the range of measurable velocities by 3D-PTV systems. The method is specifically conceived for robotic volumetric PTV measurements, but it has applications for other similar techniques. The multi-Δt method relies upon combining the information from two or more sets of double-frame images with pulse...journal article 2020
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Huang, M. (author), Ferreira, Carlos (author), Sciacchitano, A. (author), Scarano, F. (author)Wind tunnel experiments on a scaled vertical axis wind turbine (VAWT) and square porous plate with a porosity of 64% are conducted in the W-tunnel of TU-Delft. The VAWT thrusts in axial and lateral directions are measured with an in-house load cell system based on moment conservation. Wake of the VAWT in tip speed ratio of 1.5 and 2.5 and the...journal article 2020
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Spoelstra, A.M.C.M.G. (author), de Martino Norante, Luigi (author), Terra, W. (author), Sciacchitano, A. (author), Scarano, F. (author)Abstract: The Ring of Fire (RoF) measurement concept, introduced by Terra et al. (Exp Fluids 58:83. https://doi.org/10.1007/s00348-017-2331-0, 2017; Experiments in Fluids 59:120, 2018), is applied to real cyclists to enable the aerodynamic drag determination during sport action. This principle is based on large-scale stereoscopic particle...journal article 2019