Searched for: department%3A%22Flow%255C+Physics%255C+and%255C+Technology%22
(21 - 40 of 74)
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Casalino, D. (author), Grande, E. (author), Romani, G. (author), Ragni, D. (author), Avallone, F. (author)Experimental and numerical results of a propeller of 0.3 m diameter operated in quiescent standard ambient conditions at 5000 RPM and axial velocity ranging from 0 to 20 m/s and advance ratio ranging from 0 to 0.8 are presented as a preliminary step towards the definition of a benchmark configuration for low Reynolds number propeller...journal article 2021
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van Arnhem, N. (author), de Vries, R. (author), Sinnige, T. (author), Vos, Roelof (author), Veldhuis, L.L.M. (author)In this combined experimental and numerical study, the propeller–airframe aerodynamic interaction is characterized for an aircraft configuration with propellers mounted to the horizontal tailplane. The contributions of the propeller and airframe to the overall loading are distinguished in the experimental analyses by using a combination of...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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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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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)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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Lima Pereira, L.T. (author), Ragni, D. (author), Avallone, F. (author), Scarano, F. (author)Abstract: Measurements of distributed surface pressure fluctuations over trailing-edge serrations at a Reynolds number Re <sub>θ</sub> = 4900 are performed with time-resolved 3D particle imaging velocimetry using helium filled soap bubbles as flow tracers. The sparse velocity vector field obtained with Lagrangian particle tracking is densely...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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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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Ujjaini Kempaiah, K. (author), Scarano, F. (author), Elsinga, G.E. (author), van Oudheusden, B.W. (author), Bermel, Leon (author)The reduction of turbulent skin-friction drag and the response of vortical structures in a zero-pressure gradient, turbulent boundary layer subjected to spanwise wall oscillation is investigated using planar and tomographic particle image velocimetry (PIV). The experiments are conducted at a momentum based Reynolds number of 1000, while the...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
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Engler Faleiros, D. (author), Tuinstra, Marthijn (author), van Rooijen, Bart D. (author), Scarano, F. (author), Sciacchitano, A. (author)This work evaluates the use of helium-filled soap bubbles (HFSB) for Particle Image Velocimetry (PIV) measurements at high Reynolds numbers (up to 3.2 million) in aeronautics. The measurements are performed in the Low Speed Tunnel (LST) of the German-Dutch Wind Tunnels (DNW) using a high-lift airfoil in close-to-stall conditions up to 70 m/s....conference paper 2019
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Jux, C. (author), Scarano, F. (author), Sciacchitano, A. (author)A multi-model method for static pressure evaluations based on 3D PTV data is presented. The volumetric measurement domain is partitioned into an irrotational part where pressure is evaluated in a point-wise manner through Bernoulli’s equation, and a rotational domain where the pressure gradient is spatially integrated. In a third step, the field...conference paper 2019
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Gonzalez Saiz, G. (author), Sciacchitano, A. (author), Scarano, F. (author)The time-segment assimilation (TSA) method levers upon the spatio-temporal information from a finite number of successive time samples of particle velocity, coming from PTV and STB, into a refined spatial reconstruction of the velocity field of the flow. The method recently introduced by Schneiders and Scarano (2018) is elaborated here further...conference paper 2019
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Terra, W. (author), Sciacchitano, A. (author), Scarano, F. (author)The distribution of the critical velocity (point of minimum aerodynamic drag) is determined along the body of a time-trial cyclist by flow measurement in the model's near-wake.journal article 2019
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Hedayati, R. (author), Rubio Carpio, A. (author), Luesutthiviboon, S. (author), Ragni, D. (author), Avallone, F. (author), Casalino, D. (author), van der Zwaag, S. (author)Studies on porous trailing edges, manufactured with open-cell Ni-Cr-Al foams with sub-millimeter pore sizes, have shown encouraging results for the mitigation of turbulent boundary-layer trailing-edge noise. However, the achieved noise mitigation is typically dependent upon the pore geometry, which is fixed after manufacturing. In this study,...journal article 2019
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Engler Faleiros, D. (author), Tuinstra, Marthijn (author), Sciacchitano, A. (author), Scarano, F. (author)The operating regimes of an orifice-type helium-filled soap bubbles (HFSB) generator are investigated for several combinations of air, helium and soap flow rates to establish the properties of the production process and the resulting tracers. The geometrical properties of the bubbles, the production regimes and the production rates are studied...journal article 2019
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Schneiders, J.F.G. (author), Scarano, F. (author), Jux, C. (author), Sciacchitano, A. (author)This study describes the working principles of the coaxial volumetric velocimeter (CVV) for wind tunnel measurements. The measurement system is derived from the concept of tomographic PIV in combination with recent developments of Lagrangian particle tracking. The main characteristic of the CVV is its small tomographic aperture and the...journal article 2018
Searched for: department%3A%22Flow%255C+Physics%255C+and%255C+Technology%22
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