Searched for: author:"Kotsonis, M."
(1 - 20 of 52)

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Zoppini, G. (author), Ragni, D. (author), Kotsonis, M. (author)
An experimental parametric study of the effect of discrete roughness elements (DRE) on the development and breakdown of stationary crossflow instability on a swept wing is presented. A systematic investigation of the receptivity to various elements height and chord locations is carried out in a crossflow dominated flow. The flow is globally and...
conference paper 2021
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Casacuberta Puig, J. (author), Hickel, S. (author), Kotsonis, M. (author)
We study the interaction between a stationary crossflow instability and forward-facing steps in a swept-wing boundary layer using Direct Numerical Simulations (DNS). The station- ary primary crossflow mode is imposed at the inflow. Steps of several heights are modeled. Particular emphasis is placed on ensuring a fully stationary solution, in...
conference paper 2021
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Peng, K. (author), Kotsonis, M. (author)
Plasma-based flow control poses a simple and robust technique for transition delay on swept wings. However, a clear understanding of how plasma actuators affect crossflow instabilities is necessary to develop and mature crossflow control based on plasma actuators. In this paper, the design of a new swept wing model optimised for the study of...
conference paper 2021
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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
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Hehner, M. T. (author), Gatti, D. (author), Kriegseis, J. (author), Mattern, P. (author), Kotsonis, M. (author)
A modified concept for generating DBD-based virtual spanwise wall oscillations is introduced in continuation of earlier efforts by Hehner et al. (2019) ["Stokes-layer formation under absence of moving parts – A novel oscillatory plasma actuator design for turbulent drag reduc-tion", Phys. Fluids 31, 051701]. Four groups of a multi-electrode...
conference paper 2020
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Yadala, Srikar (author), Benard, Nicolas (author), Kotsonis, M. (author), Moreau, Eric (author)
The influence of spanwise-uniform (linear) forcing applied by a dielectric barrier discharge (DBD) plasma actuator on the growth of a plane mixing layer and the dynamics of large-scale spanwise vortices within, are investigated experimentally. Quantitative spatio-temporal measurement of the flow field is acquired using high-speed planar particle...
conference paper 2020
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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
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Benard, Nicolas (author), Zong, H. (author), Zhang, Yang (author), Kotsonis, M. (author), Acher, Gwenael (author), Cattafesta, Louis N. (author), Bonnet, Jean-Paul (author), Moreau, Eric (author)
Active flow control is demanding for new actuation technologies as none of the actual available actuators has reached all the criterions for expecting an implementation in the coming years. Here, a new type of pulsed jet is designed and preliminary measurements of its performances in quiescent flow are conducted. Pulsed operation has been chosen...
conference paper 2020
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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
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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
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Kurelek, J.W. (author), Yarusevych, S. (author), Kotsonis, M. (author)
This work examines flow development in a laminar separation bubble (LSB) undergoing natural transition and transition controlled with two-dimensional and spanwise modulated disturbances. The investigation is carried out in a series of wind tunnel tests, with the separation bubble formed over a flat plate subjected to an adverse pressure...
conference paper 2019
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Rizzo, Paolo (author), Serpieri, J. (author), Kotsonis, M. (author)
The present work is an experimental investigation of stationary crossflow (CF) instability-induced transition of the boundary layer over a 45°swept wing, under varying free-stream turbulence, surface roughness, angle of attack and Reynolds number. Key topological features of the transition front, such as the mean transition location and the...
conference paper 2019
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Yadala, Srikar (author), Benard, Nicolas (author), Kotsonis, M. (author), Kerherve, Franck (author), Moreau, Eric (author)
The influence of linear (spanwise-uniform) forcing applied by a DBD plasma actuator on the growth of a turbulent mixing layer and the dynamics of large-scale spanwise vortices, are investigated experimentally. Furthermore, the freestream turbulence intensity in the low-velocity stream is maintained at a high level to examine its impact on the...
conference paper 2019
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Zong, H. (author), Chiatto, Matteo (author), Kotsonis, M. (author), de Luca, Luigi (author)
The plasma synthetic jet actuator (PSJA), also named as sparkjet actuator, is a special type of zero-net mass flux actuator, driven thermodynamically by pulsed arc/spark discharge. Compared to widely investigated mechanical synthetic jet actuators driven by vibrating diaphragms or oscillating pistons, PSJAs exhibit the unique capability of...
review 2018
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Zong, H. (author), van Pelt, T. (author), Kotsonis, M. (author)
Abstract: An array of 26 plasma synthetic jet actuators (PSJA) is flush-mounted on a NACA-0015 airfoil model to control the leading-edge flow separation at moderate Reynolds number (Re<sub>c</sub>= 1.7 × 10 <sup>5</sup>). The stall angle of this airfoil is postponed from 15. 5 <sup>∘</sup> to approximately 22 <sup>∘</sup>, and the peak lift...
journal article 2018
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Kurelek, J.W. (author), Kotsonis, M. (author), Yarusevych, S. (author)
Transition and flow development in a separation bubble formed on an airfoil are studied experimentally. The effects of tonal and broadband acoustic excitation are considered since such acoustic emissions commonly result from airfoil self-noise and can influence flow development via a feedback loop. This interdependence is decoupled, and the...
journal article 2018
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Groot, K.J. (author), Serpieri, J. (author), Pinna, Fabio (author), Kotsonis, M. (author)
A combined experimental and numerical approach to the analysis of the secondary stability of realistic swept-wing boundary layers is presented. Global linear stability theory is applied to experimentally measured base flows. These base flows are three-dimensional laminar boundary layers subject to spanwise distortion due to the presence of...
journal article 2018
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Serpieri, J. (author), Kotsonis, M. (author)
In this study, experiments are performed towards the identification and measurement of unsteady modes occurring in a transitional swept wing boundary layer. These modes are generated by the interaction between the primary stationary and travelling cross-flow instabilities or by secondary instability mechanisms of the stationary cross-flow...
journal article 2018
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Michelis, Theodorus (author), Yarusevych, S. (author), Kotsonis, M. (author)
This work investigates the three-dimensional, spatio-Temporal flow development in the aft portion of a laminar separation bubble. The bubble is forming on a flat plate geometry, subjected to an adverse pressure gradient, featuring maximum reverse flow of approximately 2Â % of the local free-stream velocity. Time-resolved velocity measurements...
journal article 2018
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Yadala, Srikar (author), Hehner, M.T. (author), Serpieri, J. (author), Benard, Nicolas (author), Dörr, Philipp C. (author), Kloker, Markus J. (author), Kotsonis, M. (author)
Control of laminar-to-turbulent transition on a swept-wing is achieved by base-flow modification in an experimental framework, up to a chord Reynolds number of 2.5 million. This technique is based on the control strategy used in the numerical simulation by Dörr &amp; Kloker (J. Phys. D: Appl. Phys., vol. 48, 2015b, 285205). A spanwise uniform...
journal article 2018
Searched for: author:"Kotsonis, M."
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