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D'Aguanno, A. (author)The flight envelope of an aircraft operating at high subsonic velocities is bounded by several limitations, one of these consists in thewing experiencing oscillations of a shockwave on its suction side for a certain range ofMach number (Ma), angle of attack (®) and Reynolds number (Re). This phenomenon is referred to as transonic buffet and it...doctoral thesis 2023
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Timmer, W.A. (author), Bak, Christian (author)This chapter focuses on airfoils for wind turbine blades and their characteristics. The use of panel codes such as XFOIL and RFOIL and CFD codes for the prediction of airfoil characteristics is briefly described. This chapter then discusses the requirements for wind turbine blade airfoils and the effect of leading edge roughness and Reynolds...book chapter 2023
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Gutiérrez, R. (author), Zamponi, R. (author), Ragni, D. (author), Llorente, Elena (author), Aranguren, Patricia (author)Modern wind turbines employ thick airfoils in the outer region of the blade with strong adverse pressure gradients and high sensitivity to flow separation, which can be anticipated by leading-edge roughness. However, Reynolds average Navier-Stokes simulations currently overpredict the Reynolds shear stresses near the surface, and the flow...journal article 2023
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Zamponi, R. (author)The interaction of an airfoil with incident turbulence is an important source of aerodynamic noise in numerous applications, such as turbofan engines, cooling systems for automotive and construction industries, high-lift devices on aircraft wings, and landing gear systems. In these instances, turbulence is generally produced by elements that are...doctoral thesis 2021
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De Tavernier, D. (author)As wind farms tend to move towards deeper waters with better wind resources, the classical top-heavy horizontal-axis wind turbines (HAWTs) become particularly challenging. This raises the question whether other concepts could be more suitable and compatible with the deep-sea floating conditions. Hence, the interest in vertical-axis wind turbines...doctoral thesis 2021
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Teruna, C. (author), Avallone, F. (author), Casalino, D. (author), Ragni, D. (author)A lattice-Boltzmann method has been employed to study the aeroacoustics and aerodynamics of airfoils equipped with leading edge treatments, namely the porous leading edge and leading edge serrations. The present study aims to identify the differences in noise reduction mechanisms between the two treatments. Within the context of...journal article 2021
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Timmer, W.A. (author)A relatively simple method is presented to predict the maximum two-dimensional drag coefficient of an airfoil only using its shape. The method is based on a contribution related to the leading edge thickness in terms of the y/c coordinate at x/c=0.0125 and a contribution related to the trailing edge flow angle which appears also to be...journal article 2020
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Zamponi, R. (author), Satcunanathan, S. (author), Moreau, S. (author), Ragni, D. (author), Meinke, M. (author), Schröder, W. (author), Schram, C. (author)A possible strategy for the reduction of the aeroacoustic noise generated by turbulence interacting with a wing profile, also referred to as leading-edge noise, is represented by the implementation of a porous medium in the structure of the airfoil. However, the physical mechanisms involved in this noise mitigation technique remain unclear....journal article 2020
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Mertens, C. (author), Wolf, C. Christian (author), Gardner, Anthony D. (author), Schrijer, F.F.J. (author), van Oudheusden, B.W. (author)Advanced data processing methods for detecting unsteady boundary layer transition in periodic aerodynamic processes by means of infrared thermography measurements are presented. The thermal radiation emitted from the heated suction surface of a pitching airfoil model in subsonic flow is measured with an infrared camera. The unsteady boundary...journal article 2020
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Thedens, P. (author), De Oliveira Andrade, G.L. (author), Schmehl, R. (author)We present a multidisciplinary design optimization method for the profile and structural reinforcement layout of a ram‐air kite rib. The aim is to minimize the structural elastic energy and to maximize the traction power of a ram‐air kite used for airborne wind energy generation. Because of the large deformations occurring during flight, a fluid...journal article 2019
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De Tavernier, D. (author), Ferreira, Carlos (author), van Bussel, G.J.W. (author)To advance the design of a multimegawatt vertical-axis wind turbine (VAWT), application-specific airfoils need to be developed. In this research, airfoils are tailored for a VAWT with variable pitch. A genetic algorithm is used to optimise the airfoil shape considering a balance between the aerodynamic and structural performance of airfoils. At...journal article 2019
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Teruna, C. (author), Ragni, D. (author), Avallone, F. (author), Casalino, D. (author)This manuscript presents a rod-linear cascade model for emulating rotor-stator interaction noise. The model is intended as a test platform for studying noise mitigation techniques for a turbofan fan stage, while it also extends the classical rod-airfoil configuration by considering a row of blades based on realistic geometrical details. The...journal article 2019
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Spectral analysis of New MEXICO standstill measurements to investigate vortex shedding in deep stallKhan, Muhammad A. (author), Ferreira, Carlos (author), Schepers, J.G. (author), Sørensen, Niels N. (author)Spectral analysis was performed on the time series data computed from pressure measurements on the New MEXICO (Model Rotor Experiments under Controlled Conditions) rotor in standstill conditions. As a priori, 3D airfoil polars were recreated from standstill measurements and compared against 2D airfoil polars and flat plate theory results to...journal article 2019
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Folkersma, M.A.M. (author), Schmehl, R. (author), Viré, A.C. (author)We present a computational fluid dynamic analysis of boundary layer transition on leading edge inflatable kite airfoils used for airborne wind energy generation. Because of the operation in pumping cycles, the airfoil is generally subject to a wide range of Reynolds numbers. The analysis is based on the combination of the shear stress transport...journal article 2019
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Bauer, F. (author), Kennel, R.M. (author), Hackl, C.M. (author), Campagnolo, F. (author), Patt, M. (author), Schmehl, R. (author)As an alternative to conventional wind turbines, this study considered kites with onboard wind turbines driven by a high airspeed due to crosswind flight (“drag power”). The hypothesis of this study was, that if the kite's lift coefficient is maximized, then the power, energy yield, allowed costs and profit margin are also maximized. This...journal article 2018
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Yarusevych, S. (author), Kotsonis, M. (author)This work examines the effect of local active flow control on stability and transition in a laminar separation bubble. Experiments are performed in a wind tunnel facility on a NACA 0012 airfoil at a chord Reynolds number of 130 000 and an angle of attack of 2 degrees. Controlled disturbances are introduced upstream of a laminar separation...journal article 2017
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Lara-Quintanilla, A. (author)The design of aerodynamic airfoils are optimized for certain conditions. For instance, the shape of the wings of fixed-wing aircrafts are designed and optimized for a certain flight condition (in terms of altitude, speed, aircraft weight, etc.). However, these flight conditions vary significantly during the flight. Currently, aircraft are...doctoral thesis 2016
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Gillebaart, E. (author), De Breuker, R. (author)Low-fidelity isogeometric aeroelastic analysis has not received much attention since the introduction of the isogeometric analysis (IGA) concept, while the combination of IGA and the boundary element method in the form of the potential flow theory shows great potential. This paper presents a two-dimensional low-fidelity aeroelastic analysis and...journal article 2016
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Gillebaart, E. (author), De Breuker, R. (author)Low-fidelity isogeometric aeroelastic analysis has not received much attention since the introduction of the isogeometric analysis (IGA) concept, while the combination of IGA and the boundary element method in the form of the potential flow theory shows great potential. This paper presents a two-dimensional low-fidelity aeroelastic optimization...conference paper 2015
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Pröbsting, S. (author)Noise generated aerodynamically by the airflow over a lifting surface is often of concern for applications as diverse as air and ground transportation, heating, ventilation, air-conditioning systems, and wind turbines. The thesis describes the application of advanced optical flow measurements techniques for the visualization and description of...doctoral thesis 2015