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Jaiswal, P. (author), Moreau, Stéphane (author), Avallone, F. (author), Ragni, D. (author), Pröbsting, S. (author)Two-point velocity statistics near the trailing edge of a controlled diffusion airfoil are obtained, both experimentally and analytically, by decomposing Poisson's equation for pressure into the mean-shear (MS) and turbulence-turbulence (TT) interaction terms. The study focuses on the modeling of each interaction term, in order to allow for...journal article 2020
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Zhang, Xueqing (author), Sciacchitano, A. (author), Pröbsting, S. (author)Particle image velocimetry for the experimental assessment of trailing edge noise sources has become focus of research in recent years. The present study investigates the feasibility of the noise prediction for high-lift devices based on time-resolved particle image velocimetry (PIV). The model under investigation is a NACA 0015 airfoil with...journal article 2018
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Schneiders, J.F.G. (author), Avallone, F. (author), Pröbsting, S. (author), Ragni, D. (author), Scarano, F. (author)The power spectral density and coherence of temporal pressure fluctuations are obtained from low-repetition-rate tomographic PIV measurements. This is achieved by extension of recent single-snapshot pressure evaluation techniques based upon the Taylor’s hypothesis (TH) of frozen turbulence and vortex-in-cell (VIC) simulation. Finite time...journal article 2018
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Arce Leon, C.A. (author), Merino Martinez, R. (author), Ragni, D. (author), Avallone, F. (author), Scarano, F. (author), Pröbsting, S. (author), Snellen, M. (author), Simons, D.G. (author), Madsen, Jesper (author)The broadband noise generated by the scattering of turbulent flow at the trailing edge of a NACA 0018 airfoil with trailing edge serrations is investigated, varying both the airfoil angle of attack and serration flap angle. Acoustic emissions from the trailing edge are measured using a microphone array. The noise level is observed to be...journal article 2017
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Arce Leon, C.A. (author), Merino Martinez, R. (author), Pröbsting, S. (author), Ragni, D. (author), Avallone, F. (author)The trailing edge of a NACA 0018 airfoil is modified through the attachment of serrations with different degrees of permeability. Acoustic beamforming is used to inspect the turbulent boundary layer-trailing edge noise emissions from the unmodified and serrated trailing edges. Different freestream velocities and angles of attack are investigated...journal article 2017
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Arce Leon, C.A. (author), Merino Martinez, R. (author), Ragni, D. (author), Pröbsting, S. (author), Avallone, F. (author), Singh, A. (author), Madsen, Jesper (author)Trailing edge serrations have been proven to work as a passive noise reduction device. Nevertheless, they have also previously been found to increase noise in a particular frequency range, argued in earlier research to be due to the misalignment of the serrations with the direction of the flow in the wake. It emerges as a high-frequency noise...conference paper 2017
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Zhang, Xueqing (author), Sciacchitano, A. (author), Pröbsting, S. (author)The present study investigates the feasibility of high-lift devices noise prediction based on measurements of time-resolved particle image velocimetry (TR-PIV). The model under investigation is a NACA 0015 airfoil with Gurney flap with height of 6% chord length. The velocity fields around and downstream the Gurney flap are measured by PIV and...conference paper 2016
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Guan, Yaoyi (author), Pröbsting, S. (author), Stephens, David (author), Gupta, A. (author), Morris, Scott C. (author)Trailing edge and wake flows are of interest for a wide range of applications. Small changes in the design of asymmetrically beveled or semi-rounded trailing edges can result in significant difference in flow features which are relevant for the aerodynamic performance, flow-induced structural vibration and aerodynamically generated sound. The...journal article 2016
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Shah, J. (author), Sciacchitano, A. (author), Pröbsting, S. (author)The present study employs simultaneous planar TR-PIV and microphone measurements to obtain the flow dynamics and aeroacoustic causality correlation associated with a Gurney flap of various sizes in case of low Mach and high Reynolds number flows. The objectives are to investigate the secondary shedding mode for the case of a turbulent boundary...conference paper 2016
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Schneiders, J.F.G. (author), Pröbsting, S. (author), Dwight, R.P. (author), Van Oudheusden, B.W. (author), Scarano, F. (author)A method is proposed to determine the instantaneous pressure field from a single tomographic PIV velocity snapshot and is applied to a flat-plate turbulent boundary layer. The main concept behind the single-snapshot pressure evaluation method is to approximate the flow acceleration using the vorticity transport equation. The vorticity field...journal article 2016
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Schneiders, J.F.G. (author), Pröbsting, S. (author), Dwight, R.P. (author), Van Oudheusden, B.W. (author), Scarano, F. (author)A method is proposed to determine the instantaneous pressure field from a single tomographic PIV velocity snapshot and is applied to a flat-plate turbulent boundary layer. The main concept behind the single-snapshot pressure evaluation method is to approximate the flow acceleration using the vorticity transport equation. The vorticity field...journal article 2016
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Schneiders, J.F.G. (author), Pröbsting, S. (author), Dwight, R.P. (author), Van Oudheusden, B.W. (author), Scarano, F. (author)A method is proposed to determine the instantaneous pressure field from a single tomographic PIV velocity snapshot and is applied to a flat-plate turbulent boundary layer. The main concept behind the single-snapshot pressure evaluation method is to approximate the flow acceleration using the vorticity transport equation. The vorticity field...journal article 2016
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Arce Leon, C.A. (author), Ragni, D. (author), Pröbsting, S. (author), Scarano, F. (author), Madsen, Jesper (author)The flow past a NACA 0018 airfoil with sawtooth trailing edge serrations has been investigated using stereoscopic particle image velocimetry (PIV). The serration flap angle and airfoil incidence are varied in order to study the effect of secondary flow establishing between the suction and pressure sides of the serrations. The flow topology...journal article 2016
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Avallone, F. (author), Pröbsting, S. (author), Ragni, D. (author)The three-dimensional flow field over the suction side of a NACA 0018 airfoil with trailing-edge serrations was studied by means of time-resolved tomographic particle image velocimetry. Mean flow results show that the boundary layer thickness decreases along the streamwise direction with a corresponding reduction of the size of the turbulent...journal article 2016
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Pröbsting, S. (author)Noise generated aerodynamically by the airflow over a lifting surface is often of concern for applications as diverse as air and ground transportation, heating, ventilation, air-conditioning systems, and wind turbines. The thesis describes the application of advanced optical flow measurements techniques for the visualization and description of...doctoral thesis 2015
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Pröbsting, S. (author), Serpieri, J. (author), Scarano, F. (author)The present study investigates the mechanisms associated with tonal noise emission from a NACA 0012 aerofoil at moderate incidence (0; 1; 2 and 4 angle of attack) and with Reynolds numbers ranging from 100 000 to 270 000. Simultaneous time-resolved particle image velocimetry (PIV) of the aeroacoustic source region near the trailing edge and...journal article 2014
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Pröbsting, S. (author), Serpieri, J. (author), Scarano, F. (author)Tonal noise generated by airfoils observed at low to moderate Reynolds numbers is related to laminar boundary layer instabilities, which has lead to the term laminar boundary layer instability noise. The particular features of the acoustic spectrum have been discussed and a number of theories have been proposed in literature over the past 50...conference paper 2013
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Pröbsting, S. (author), Serpieri, J. (author), Scarano, F. (author)Tonal noise generated by airfoils observed at low to moderate Reynolds numbers is related to laminar boundary layer instabilities, which has lead to the term laminar boundary layer instability noise. The particular features of the acoustic spectrum have been discussed and a number of theories have been proposed in literature over the past 50...conference paper 2013
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Tuinstra, M. (author), Probsting, S. (author), Scarano, F. (author)The feasibility of aeroacoustic noise predictions based on Particle Image Velocimetry (PIV) measurements is studied. For this purpose, experiments are conducted on a sharp trailing edge (TE) flow developed along a flat plate at free stream velocity of 15m/s. The acoustic emissions were characterized in the NLR Small Anechoic Wind Tunnel (KAT) by...conference paper 2013
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Pröbsting, S. (author)In the past, different modifications of trailing-edges have been investigated with the aim to reduce noise emissions. One promising solution, which has been shown to reduce the intensity of trailing-edge noise, is the application of so-called sawtooth serrations with different proportions and sizes. Current research aims at applying new tools of...master thesis 2011