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Baars, W.J. (author), Dacome, G. (author), Lee, Myoungkyu (author)Wall-pressure fluctuations are a practically robust input for real-time control systems aimed at modifying wall-bounded turbulence. The scaling behaviour of the wall-pressure-velocity coupling requires investigation to properly design a controller with such input data so that it can actuate upon the desired turbulent structures. A...journal article 2024
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Baars, T.F. (author)Alluvial deposits in the subsurface are essential for geo-energy production and storage in many regions worldwide. Accurate correlation and characterisation of alluvial stratigraphy requires an understanding of how river channels were spatially deposited, and which geomorphological processes acted upon them. This doctoral dissertation the...doctoral thesis 2023
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Dekker, H.N.J. (author), Tuinstra, M (author), Baars, W.J. (author), Scarano, F. (author), Ragni, D. (author)A semi-emperical model is developed, able to capture the aeropropulsive performance characteristics of Over-The-Wing propellers at incidence. The model is based on an hypothesis on the interactions of the propeller- and wing-induced flow fields. Effects of these interactions on the both the thrust and lift are written in a form in which the...conference paper 2023
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Baars, W.J. (author), Ragni, D. (author)Rotor noise comprises harmonic features, related to the blade passing frequency, as well as broadband noise. Even though acoustic spectra yield frequency-distributions of acoustic energy within pressure time series, they do not reveal phase-relations between different frequency components. The latter are of critical importance for the...conference paper 2023
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Baars, T.F. (author), Huis in ‘t Veld, Richard (author), Zhang, Linzhi (author), Koopmans, Maaike (author), McLean, Duncan (author), Martinius, A.W. (author), Abels, H.A. (author)Orbital driven climate control on sedimentation produces regional, stratigraphically repetitive characters and so cyclostratigraphic correlation can improve correlation and identify stratigraphic trends in borehole sections. This concept is commonly used to correlate marine and lacustrine strata. However, in the alluvial domain, its use is more...journal article 2023
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- Dekker, H.N.J. (author), Tuinstra, Marthijn (author), Baars, W.J. (author), Scarano, F. (author), Ragni, D. (author) conference paper 2023
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- Sloff, C.J. (author), Jumelet, D. (author), Baars, L. (author) abstract 2023
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Li, Mogeng (author), Baars, W.J. (author), Marusic, Ivan (author), Hutchins, Nicholas (author)We investigate the underlying physics behind the change in amplitude modulation coefficient in noncanonical wall-bounded flows in the framework of the inner-outer interaction model (IOIM) [Baars, Phys. Rev. Fluids 1, 054406 (2016)2469-990X10.1103/PhysRevFluids.1.054406]. The IOIM captures the amplitude modulation effect, and here we focus on...journal article 2023
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Dekker, H.N.J. (author), Baars, W.J. (author), Scarano, F. (author), Tuinstra, Marthijn (author), Ragni, D. (author)The unsteady flow behaviour of two side-by-side rotors in ground proximity is experimentally investigated. The rotors induce a velocity distribution interacting with the ground causing the radial expansion of the rotor wakes. In between the rotors, an interaction of the two wakes takes place, resulting in an upward flow similar to a fountain....journal article 2023
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Carrasco Grau, J. (author), van Campenhout, O.W.G. (author), Hartog, F.H. (author), van Nesselrooij, M. (author), Baars, W.J. (author), Schrijer, F.F.J. (author)Chevron-shaped protrusions have been proposed in the literature for turbulent skin friction reduction. However, there is no consensus on the performance of this passive flow control technique; both an increase and a decrease in drag have been observed in previous studies. There is also no experimental evidence to support the working mechanism...journal article 2023
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Li, Xuebo (author), Hutchins, Nicholas (author), Zheng, Xiaojing (author), Marusic, Ivan (author), Baars, W.J. (author)A large-scale spanwise and wall-normal array of sonic anemometers in the atmospheric surface layer is used to acquire all three components of instantaneous fluctuating velocity as well as temperature in a range of stability conditions. These data permit investigation of the three-dimensional statistical structure of turbulence structures....journal article 2022
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Dekker, H.N.J. (author), Ragni, D. (author), Baars, W.J. (author), Scarano, F. (author), Tuinstra, Marthijn (author)An experimental investigation is conducted to study the aerodynamic behavior of a two-rotor system in ground proximity. The counter-rotating rotors are placed side-by-side in the hovering condition. The time-averaged and unsteady flow behavior is studied when the rotor-to-rotor lateral distance and the distance between the rotors and the...journal article 2022
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Zhang, Jianguo (author), Jiang, Zaixing (author), Liang, Chao (author), Baars, T.F. (author), Wang, Y. (author), Abels, H.A. (author)The middle Eocene Dongying sag in the Bohai Bay Basin of China has an estimated shale oil resource of approximately 1.1 billion t (8.06 billion bbl); flows of shale oil have been produced in the succession from tens of wells, where the daily production of a single well generally varies between 10 and 100 t (73.3–733 bbl). Therein, the mudrock...journal article 2022
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Wang, Y. (author), Baars, T.F. (author), Sahoo, H. (author), Storms, J.E.A. (author), Martinius, A.W. (author), Gingerich, Philip (author), Abels, H.A. (author)ABSTRACT The lower Eocene Willwood Formation of the Bighorn Basin, Wyoming, USA, is an alluvial succession with a sand content varying around 25 palaeoenvironments and palaeoclimates, as well as sedimentological and stratigraphic analysis. Channel dynamics were studied at a relatively low resolution throughout the basin over the geological time...journal article 2022
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Ragni, D. (author), Fiscaletti, D. (author), Baars, W.J. (author)Abstract: This work combines the latest advancements in time marching of 3D vector fields from tomographic particle image velocimetry, with an adapted version of Lighthill’s formulation, for the prediction of far-field jet noise. Three-dimensional velocity vector fields of the jet flow are first reconstructed from a tomographic volume of 4× 3...journal article 2022
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Baars, W.J. (author), Lee, Myoungkyu (author)Since wall-pressure fluctuations would form a practically-robust input to a real-time active controller of wall-bounded turbulence, it is of high practical interest to study the scaling behavior of the wall-pressure-velocity coupling. This work investigates the coupling of the wall-pressure fluctuations with the streamwise and wall-normal...conference paper 2022
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Ujjaini Kempaiah, K. (author), Sem, Jacopo (author), Baars, W.J. (author)Rotating discs, flush-mounted within the wall beneath a turbulent boundary layer, affect the large-scale flow dynamics. An organized array of rotating discs is a surrogate for the transverse-oscillating wall concept that is known to reduce turbulent friction drag, since the convecting flow encounters a travelling wave, particularly in the...conference paper 2022
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Baars, S. (author), Schellings, G. L.M. (author), Joore, Peter (author), van Wesemael, P. J.V. (author)Research into the relationship between innovative physical learning environments (PLEs) and innovative psychosocial learning environments (PSLEs) indicates that it must be understood as a network of relationships between multiple psychosocial and physical aspects. Actors shape this network by attaching meanings to these aspects and their...journal article 2022
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Baars, Mart (author), Hellendoorn, J. (author), Alirezaei, Mohsen (author)In this research a controller is developed that can control path-tracking both within and beyond stable limit handling. The controller is based on the equations of motion of the nonlinear bicycle model. The performance of the controller is evaluated in simulation, a sensitivity analysis is performed and the controller is implemented on a 1/10...journal article 2021
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Kramer, O.J.I. (author), de Moel, P.J. (author), Padding, J.T. (author), Baars, Eric T. (author), Rutten, Sam B. (author), Elarbab, Awad H.E. (author), Hooft, Jos F.M. (author), Boek, Edo S. (author), van der Hoek, J.P. (author)Fluid flow through a bed of solid particles is an important process that occurs in full-scale water treatment operations. The Carman–Kozeny model remains highly popular for estimating the resistance across the bed. It is common practice to use particle shape factors in fixed bed state to match the predicted drag coefficient with experimentally...journal article 2021