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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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Lima Pereira, L.T. (author), Avallone, F. (author), Ragni, D. (author), Scarano, F. (author)This work discusses the physics of noise reduction achieved from serrated trailing–edges and its impact by the serration design. An experimental campaign is carried out with a benchmark 2D model based on a NACA 63<sub>3</sub>–018 airfoil. Different trailing-edge serrations are tested under several flow speeds and angles of attack conditions...journal article 2023
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Dekker, H.N.J. (author), Baars, W.J. (author), Scarano, F. (author), Tuinstra, Marthijn (author), Ragni, D. (author)The unsteady flow behaviour of two side-by-side rotors in ground proximity is experimentally investigated. The rotors induce a velocity distribution interacting with the ground causing the radial expansion of the rotor wakes. In between the rotors, an interaction of the two wakes takes place, resulting in an upward flow similar to a fountain....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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Lima Pereira, L.T. (author), Avallone, F. (author), Ragni, D. (author), Scarano, F. (author)A physical description of the flow mechanisms that govern the distribution of the wall-pressure fluctuations over the surface of a serrated trailing edge is proposed. Three main mechanisms that define the variation of turbulent pressure fluctuations across the serrated edge are discussed and semi-empirical models are formulated accordingly....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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Dekker, H.N.J. (author), Ragni, D. (author), Baars, W.J. (author), Scarano, F. (author), Tuinstra, Marthijn (author)An experimental investigation is conducted to study the aerodynamic behavior of a two-rotor system in ground proximity. The counter-rotating rotors are placed side-by-side in the hovering condition. The time-averaged and unsteady flow behavior is studied when the rotor-to-rotor lateral distance and the distance between the rotors and the...journal article 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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Lima Pereira, L.T. (author), Ragni, D. (author), Avallone, F. (author), Scarano, F. (author)The impact of aerodynamic loading on a serrated trailing edge is studied experimentally. Aerodynamic and acoustic measurements are conducted on a sawtooth-shaped trailing edge, retrofitted to a flat plate featuring a trailing-edge flap, and placed at incidence to the free-stream flow. The turbulent flow across the trailing edge is inspected...journal article 2022
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Engler Faleiros, D. (author), van den Bos, W. (author), Botto, L. (author), Scarano, F. (author)This work describes a modelling approach to SARS-CoV-2 dispersion based on experiments. The main goal is the development of an application integrated in Ansys Fluent to enable computational fluid dynamics (CFD) users to set up, in a relatively short time, complex simulations of virion-laden droplet dispersion for calculating the probability...journal article 2022
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van der Hoek, D.C. (author), Frederik, J.A. (author), Huang, M. (author), Scarano, F. (author), Ferreira, Carlos (author), van Wingerden, J.W. (author)Dynamic induction control (DIC) has proven to be an effective method of increasing the power output for a wind farm in both simulation studies and wind tunnel experiments. By pitching the blades of a wind turbine periodically, the recovery of the low-velocity wake is accelerated, thereby increasing the energy available to downstream turbines....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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Ujjaini Kempaiah, K. (author), Scarano, F. (author)Spanwise wall oscillations alter the organization of low-speed streaks and ejections in turbulent boundary layers, eventually leading to skin friction drag reduction. Such flow regimes are represented by pointwise statistics or spatial correlation. This work attempts to quantify the systematic distortions of the dominant turbulent structures...journal article 2022
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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