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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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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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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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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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), Avallone, F. (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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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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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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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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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
Searched for: author%3A%22Kotsonis%2C+M.%22
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