Searched for: author%3A%22Kotsonis%2C+M.%22
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Barahona Lopez, M. (author), van de Weijer, A.F. (author), Rius Vidales, A.F. (author), Kotsonis, M. (author)
One of the most critical technological challenges embedded in the electrification of future aircraft revolves around the thermal management of batteries and fuel cells. An innovative idea involves using the aircraft’s aerodynamic surfaces to dissipate the extra heat, thereby reducing the impact that traditional thermal management systems (e.g....
conference paper 2024
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Rius Vidales, A.F. (author), Barahona Lopez, M. (author), Kotsonis, M. (author)
A new experimental facility named Swept Transition Experimental Platform (STEP) has been designed and built for detailed studies of crossflow instability and its interaction with surface irregularities and varying wall temperature conditions. The STEP is designed for use in the anechoic low-turbulence wind tunnel facility at the Delft University...
conference paper 2024
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Mohammadikalakoo, B. (author), Kotsonis, M. (author), Doan, Nguyen Anh Khoa (author)
This work focuses on the suppression of Tollmien-Schlichting (TS) waves in a two-dimensional laminar boundary layer using optimized unsteady suction and blowing jets as an Active Flow Control (AFC) method. The suppression of TS waves via this AFC system is enabled through two artificial intelligence-based optimization methodologies: Single-Step...
conference paper 2024
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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
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Casacuberta Puig, J. (author), Hickel, S. (author), Kotsonis, M. (author)
Achieving and maintaining laminar flow on large swept lifting surfaces of subsonic aircraft poses a considerable challenge.
book chapter 2024
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Westerbeek, S.H.J. (author), Sumariva, Juan Alberto Franco (author), Michelis, Theodorus (author), Hein, Stefan (author), Kotsonis, M. (author)
The Parabolized Stability Equations (PSE), Adaptive Harmonic Linearized Navier-Stokes (AHLNS) and Harmonic Navier-Stokes (HNS) solvers are used to analyze the linear and nonlinear stability of swept-wing boundary layers under the influence of smooth wall deformations of varying size and geometry. Special attention is given to the validity of the...
conference paper 2023
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Zoppini, G. (author), Sequeira, A.D. (author), Michelis, Theodorus (author), Ragni, D. (author), Kotsonis, M. (author)
The present work details the steady and unsteady flow topology in the vicinity of an array of periodically spaced super-critical (i.e. causing flow tripping) discrete roughness elements (DRE) applied in a swept wing boundary layer. The stationary flow field is acquired by means of high-magnification dual-pulse tomographic particle tracking...
conference paper 2023
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Della Pia, A. (author), Michelis, Theodorus (author), Chiatto, Matteo (author), Kotsonis, M. (author), de Luca, Luigi (author)
The wake-mixing layer flow developing past a splitter plate separating two parallel gas and liquid co-flowing currents is experimentally investigated in this work. Time-resolved particle image velocimetry (TR-PIV) measurements of the two-phase velocity field are simultaneously performed in gas and liquid streams, shedding light on both mean ...
conference paper 2023
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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
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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
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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
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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
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Casacuberta Puig, J. (author), Groot, K.J. (author), Hickel, S. (author), Kotsonis, M. (author)
The evolution of secondary instabilities in a three-dimensional stationary-crossflow-domina- ted boundary layer is investigated by means of Direct Numerical Simulations (DNS) and linear spanwise BiGlobal stability analysis. Single-frequency unsteady disturbances and a critical stationary crossflow mode are considered. Unsteady perturbation...
conference paper 2022
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Zoppini, G. (author), Ragni, D. (author), Kotsonis, M. (author)
The application of an isolated roughness element in the laminar boundary layer developing on the surface of a wing, introduces flow instabilities that eventually lead to the breakdown of the laminar flow structures and the formation of a turbulent wedge. The present work, investigates the instabilities and transition process initiated by an...
conference paper 2022
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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
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Scarano, F. (author), Ujjaini Kempaiah, K. (author), Kotsonis, M. (author)
In the present work, planar and tomographic PIV are used to investigate how the organisation of wall turbulence is altered when actuators are operated with the objective of reducing the skin friction drag. When the wall is mechanically oscillated in the spanwise direction, high-resolution planar PIV enable the direct measurement of wall shear...
conference paper 2022
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Barahona Lopez, M. (author), Rius Vidales, A.F. (author), Tocci, F. (author), Ziegler, P. (author), Hein, S. (author), Kotsonis, M. (author)
This work presents an experimental and numerical investigation jointly conducted by TU Delft and DLR on Tollmien-Schlichting (TS) waves interaction with a Forward-Facing Step (FFS). Experiments are conducted at the TU Delft low-turbulence anechoic wind tunnel on an unswept flat plate model. Single-frequency disturbances are introduced using...
conference paper 2022
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Zoppini, G. (author), Michelis, Theodorus (author), Ragni, D. (author), Kotsonis, M. (author)
This work presents the first reported experimental characterization of the flow field in the direct vicinity of discrete roughness elements (DRE), in a swept wing boundary layer. High magnification tomographic Particle Tracking Velocimetry (3D-PTV) measurements are used to acquire time-averaged velocity and standard deviation fields in a 3D...
conference paper 2022
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Krochak, O.O. (author), Casacuberta Puig, J. (author), Hickel, S. (author), Kotsonis, M. (author)
conference paper 2022
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Westerbeek, S.H.J. (author), Kotsonis, M. (author)
The nonlinear stability of three-dimensional boundary layers over various undulated surfaces was calculated using the generalized Nonlinear Parabolized Stability Equations (NPSE). The results are compared with a flat plate configuration to assess the effect of the undulation shape on the stability of the boundary layer. It was found that the...
conference paper 2022
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