Searched for: author%3A%22Kotsonis%2C+M.%22
(1 - 20 of 46)

Pages

document
Della Pia, A. (author), Michelis, Theodorus (author), Chiatto, Matteo (author), Kotsonis, M. (author), De Luca, Luigi (author)
This study reports the first time-resolved particle image velocimetry characterization of a planar two-phase mixing layer flow, whose velocity field is measured simultaneously in gas and liquid streams. Two parallel air and water flows meet downstream of a splitter plate, giving rise to an initially spanwise invariant configuration. The aim...
journal article 2024
document
Michelis, Theodorus (author), De Koning, C. (author), Kotsonis, M. (author)
The influence of a wall-embedded Helmholtz resonator on the development and stability of Tollmien-Schlichting (TS) waves is investigated numerically and experimentally for a range of frequencies extending from below to above resonance. Interactions are found to be limited in the near-wall region and toward the trailing edge of the resonator...
journal article 2023
document
Michelis, Theodorus (author), Putranto, A. B. (author), Kotsonis, M. (author)
A novel method for control of convective boundary layer instabilities using metamaterial concepts is investigated. Attenuation of Tollmien-Schlichting (TS) waves with surface-embedded one-dimensional phononic crystals (PCs) is theoretically and numerically modeled, capitalizing on the inherent frequency band stop of PCs. The PC is tuned to...
journal article 2023
document
Zoppini, G. (author), Michelis, Theodorus (author), Ragni, D. (author), Kotsonis, M. (author)
This work presents the first experimental characterization of the flow field in the vicinity of periodically spaced discrete roughness elements (DRE) in a swept wing boundary layer. The time-averaged velocity fields are acquired in a volumetric domain by high-resolution dual-pulse tomographic particle tracking velocimetry. Investigation of...
journal article 2023
document
Kurelek, J.W. (author), Kotsonis, M. (author), Yarusevych, S. (author)
This investigation explores the utility of Alternating Current, Dielectric Barrier Discharge (AC-DBD) plasma actuators for producing three-dimensional disturbances of a desired spanwise wavelength via superposition. The technique utilizes two pairs of exposed and covered electrodes on a single dielectric layer arranged in streamwise...
journal article 2023
document
Hehner, Marc T. (author), Gatti, Davide (author), Kotsonis, M. (author), Kriegseis, Jochen (author)
Two different plasma actuation strategies for producing near-wall flow oscillations, namely the burst-modulation and beat-frequency mode, are characterized with planar particle image velocimetry in quiescent air. Both concepts are anticipated to work as non-mechanical surrogates of oscillating walls aimed at turbulent flow drag reduction,...
journal article 2022
document
Castellanos, Rodrigo (author), Michelis, Theodorus (author), Discetti, Stefano (author), Ianiro, Andrea (author), Kotsonis, M. (author)
The effect of streamwise plasma vortex generators on the convective heat transfer of a turbulent boundary layer is experimentally investigated. A Dielectric Barrier Discharge (DBD) plasma-actuator array is employed to promote pairs of counter-rotating, streamwise-aligned vortices embedded in a well-behaved turbulent boundary layer over a flat...
journal article 2022
document
Zoppini, G. (author), Westerbeek, S.H.J. (author), Ragni, D. (author), Kotsonis, M. (author)
The effect of discrete roughness elements on the development and breakdown of stationary crossflow instability on a swept wing is explored. Receptivity to various element heights and chordwise locations is explored using a combination of experimental and theoretical tools. Forcing configurations, determined based on linear stability...
journal article 2022
document
Zoppini, G. (author), Ragni, D. (author), Kotsonis, M. (author)
The present work is dedicated to the investigation of the effect of an isolated roughness element on a swept wing boundary layer. In particular, the flow modifications incurred by a single cylindrical element applied on a swept wing model are measured, toward describing the nature of the perturbations introduced in the flow field, their...
journal article 2022
document
Casacuberta Puig, J. (author), Hickel, S. (author), Westerbeek, S.H.J. (author), Kotsonis, M. (author)
The interaction between forward-facing steps of several heights and a pre-existing critical stationary crossflow instability of a swept-wing boundary layer is analysed. Direct numerical simulations (DNS) are performed of the incompressible three-dimensional laminar base flow and the stationary distorted flow that arise from the interaction...
journal article 2022
document
Peng, K. (author), Arkesteijn, J. P.W. (author), Avallone, F. (author), Kotsonis, M. (author)
This work experimentally investigates plasma actuator (PA) forcing effects on the base flow and developing crossflow (CF) instabilities in a swept wing boundary layer. Spanwise-invariant plasma forcing near the leading edge is configured according to the base flow modification (BFM) strategy. A simplified predictive model is constructed by...
journal article 2022
document
Zoppini, G. (author), Michelis, Theodorus (author), Ragni, D. (author), Kotsonis, M. (author)
The presented work introduces a cancellation technique, based on the linear superposition of stationary crossflow instabilities (CFIs) through the application of a streamwise series of optimally positioned discrete roughness element (DRE) arrays on a swept wing surface. The DRE arrays are designed and arranged with suitable amplitude and...
journal article 2022
document
Peng, K. (author), Avallone, F. (author), Kotsonis, M. (author)
This work investigates the response of a transitional boundary layer to spanwise-invariant dielectric barrier discharge plasma actuator (PA) forcing on a 45 ° swept wing at a chord Reynolds number of 2.17 × 10 6. Two important parameters of the PA operation are scrutinized, namely, the forcing frequency and the streamwise location of forcing....
journal article 2022
document
Stuber, V.L. (author), Kotsonis, M. (author), van der Zwaag, S. (author)
Two piezoelectric series bimorph sensors were embedded below the skin of a NACA 0012 symmetrical airfoil to detect the local state of the boundary layer during wind tunnel testing. Small vanes piercing the airfoil skin were glued onto the bimorphs providing a mechanical coupling to the local mechanical force fluctuations imparted by the local...
journal article 2022
document
Rius Vidales, A.F. (author), Kotsonis, M. (author)
Experiments have been conducted on a swept wing model in a low-turbulence wind tunnel at chord Reynolds number of to investigate the unsteady interaction of a forward-facing step (FFS) with incoming stationary crossflow (CF) vortices. The impact of varying the FFS height on the development and growth of primary and secondary CF disturbances...
journal article 2022
document
Rius Vidales, A.F. (author), Kotsonis, M. (author)
The impact of a forward-facing step (FFS) on the development of stationary crossflow instability is investigated on a swept wing model in a low-turbulence wind tunnel at chord Reynolds number of. Infrared thermography and particle image velocimetry measurements are used to quantify the transition location and growth of the crossflow...
journal article 2021
document
Merino Martinez, R. (author), Rubio Carpio, A. (author), Lima Pereira, L.T. (author), van Herk, S.W.L. (author), Avallone, F. (author), Ragni, D. (author), Kotsonis, M. (author)
The newly refurbished vertical tunnel (V-tunnel) at Delft University of Technology has been redesigned as a state-of-the-art facility for research in aeroacoustics (A-tunnel), as well as fundamental studies in laminar-turbulent transition and flow control. This manuscript focuses on the design and refurbishment aspects of the facility,...
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
Kurelek, J.W. (author), Yarusevych, S. (author), Kotsonis, M. (author)
Vortex merging in a laminar separation bubble (LSB) is studied experimentally. The bubble is formed on the suction side of a NACA 0018 airfoil at an angle of attack of 4° and a Reynolds number of 125 000. The merging process in the bubble is manipulated through acoustic forcing applied as a tone at either the fundamental vortex shedding...
journal article 2019
document
Tol, H.J. (author), Kotsonis, M. (author), de Visser, C.C. (author)
This paper investigates the use of point wall pressure measurements for output feedback control of Tollmien–Schlichtingwaves in Falkner–Skan boundary layers.Anewapproach is presented for input–outputmodeling of the linear dynamics of the fluid system and the integration withH2∕Linear Quadratic Gaussian reduced-order control design. The pressure...
journal article 2019
Searched for: author%3A%22Kotsonis%2C+M.%22
(1 - 20 of 46)

Pages