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Westerbeek, S.H.J. (author), Hulshoff, S.J. (author), Schuttelaars, H.M. (author), Kotsonis, M. (author)A nonlinear Harmonic Navier-Stokes (HNS) framework is introduced for simulating instabilities in laminar spanwise-invariant shear layers, featuring sharp and smooth wall surface protuberances. While such cases play a critical role in the process of laminar-to-turbulent transition, classical stability theory analyses such as parabolized or local...journal article 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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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
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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), 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