Searched for: subject%3A%22unsteadiness%22
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Bisbal Regidor, Àlex (author)
Within the context of the new wave of eVTOL aircraft development, Cyclotech GmbH has been working on the development of cyclorotors, a type of propeller consisting of rotating blades along a common longitudinal axis, where the pitch angle of the blades is actively controlled through what is known as a pitch curve. This thesis proposes a...
master thesis 2024
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Dhirde, Mayur (author)
The offshore wind industry is rapidly advancing, expected to play a crucial role in renewable energy production, with a growing emphasis on addressing associated environmental concerns, particularly the impact of underwater noise generated during the installation of wind turbines. In response, bubble curtain technology (BCT) has emerged as a...
master thesis 2024
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Xu, Ying (author), Casalino, D. (author), Zhang, Xiao Zheng (author), Zhang, Yong Bin (author), Bi, Chuan Xing (author)
A time-domain inverse aeroacoustic method based on the convective Ffowcs Williams–Hawkings equation is presented. The method allows to determine, in real-time, the unsteady forces exerted on rotating blades in the presence of a moving medium. The inversion procedure is based on a space-time regularization with a mixed l1,2-norm, which guarantees...
journal article 2024
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Gonzalez Saiz, G. (author)
Experimental aeroelasticity has been hindered by the intrusivity of measurement equipment and complexity of the experimental setups. Advancements in hardware development have been encouraging optical tracking techniques to replace cross correlation approaches in experimental aerodynamics. However, digital image correlation (DIC) is still the...
doctoral thesis 2023
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González Romero, Andrea (author)
As the space industry continues to grow rapidly, the development of reusable launch vehicles has become crucial in achieving cost-effective and sustainable access to space. Payload capacity optimisation has been at the forefront of this effort, leading to a renewed interest in hammerhead or bulbous payload fairing (PLF) configurations. These...
master thesis 2023
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Mertens, C. (author)
This thesis presents a novel measurement approach for aeroelastic wind tunnel testing. The key novelty of this approach is the integrated measurement of aerodynamic and structural quantities using an optical technique. The considered approach consists of combined measurements of flow tracer particles and structural markers using a Lagrangian...
doctoral thesis 2023
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Shi, Rui (author), Wüthrich, D. (author), Chanson, Hubert (author)
Transient motion, turbulence and bubble dynamics make any velocity quantification extremely difficult in unsteady gas–liquid flows. In the present study, novel Eulerian and Lagrangian techniques of velocimetry were developed, using both intrusive and non-intrusive measurements. The selected unsteady gas–liquid flow was a breaking bore,...
journal article 2023
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Shi, Rui (author), Wüthrich, D. (author), Chanson, Hubert (author)
Continuing from the part 1 (Shi et al., 2022) this paper presents an experimental investigation of transient void fraction and bubble statistics in a highly turbulent breaking bore with Fr<sub>1</sub>=2.4. The measurements were conducted using a combination of dual-tip phase-detection probes and an ultra-high-speed video camera. The enclosed...
journal article 2023
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Xu, Y. (author), Zhang, Xiao Zheng (author), Casalino, D. (author), Bi, Chuan Xing (author)
An inverse acoustic method is presented in this work, which allows to determine the spatial and temporal distribution of unsteady rotating forces from microphone array measurements. The method is based on the usage of a space–time regularization with a mixed norm. The proposed method can take advantage of a prior knowledge of the space–time...
journal article 2023
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Pinto, D. (author), Hu, L. (author), Urakawa, A. (author)
Dynamic coke-mediated dry reforming of methane (DC-DRM) is an unsteady-state strategy to overcome the limitations of co-feed operation, including the fast deactivation of the catalysts and the loss of valuable H<sub>2</sub> in the reverse water gas-shift reaction. This paper proves the feasibility of DC-DRM on Ni-based catalytic systems,...
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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Grille Guerra, Adrian (author)
Unmanned aerial vehicles have proliferated in the last few decades, with applications that include military, commercial and recreational. Their size and typical flight velocities are characterized by moderate Reynolds numbers <i>O</i>(10^4-10^5). For such conditions, boundary layers can remain laminar and therefore are highly susceptible to...
master thesis 2022
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Mertens, C. (author), Costa Fernandez, J.L. (author), Sodja, J. (author), Sciacchitano, A. (author), van Oudheusden, B.W. (author)
The aeroelastic response of a highly flexible wing to periodic gust excitation is determined experimentally. The integrated optical measurement approach that is applied provides combined measurements of the structural response of the wing and the unsteady flow field around it. The aeroelastic loads acting on the wing are derived from these...
conference paper 2022
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Li, X. (author), Hulshoff, S.J. (author), Hickel, S. (author)
Proper Orthogonal Decomposition (POD) plays an important role in the analysis of complex nonlinear systems governed by partial differential equations (PDEs), since it can describe the full-order system in a simplified but representative way using a handful of dominant dynamic modes. However, determining a POD from the results of complex...
journal article 2022
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De Tavernier, D. (author), Ferreira, Carlos (author), Goude, Anders (author)
This chapter highlights the main aerodynamic phenomena and challenges of vertical-axis wind turbines. First, an introduction is provided on the VAWT history and (dis-)advantages. The basics of VAWT aerodynamics and the various rotor simplifications/representations are presented. Further, the state-of-the art aerodynamic modeling techniques,...
book chapter 2022
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Engler Faleiros, D. (author), van den Bos, W. (author), Botto, L. (author), Scarano, F. (author)
This work describes a modelling approach to SARS-CoV-2 dispersion based on experiments. The main goal is the development of an application integrated in Ansys Fluent to enable computational fluid dynamics (CFD) users to set up, in a relatively short time, complex simulations of virion-laden droplet dispersion for calculating the probability...
journal article 2022
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Kramer, O.J.I. (author)
In drinking water treatment plants, multiphase flows are a frequent phenomenon. Examples of such flows are pellet-softening and filter backwashing where liquid-solid fluidisation is applied. A better grasp of these fluidisation processes is needed to be able to determine optimal hydraulic states. In this research, models were developed, and...
doctoral thesis 2021
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Srikanth Vasudevan, Srikanth (author)
High Altitude Long Endurance (HALE) configurations have gained much popularity in the recent past. Although, HALE aircraft enable efficient and environmental-friendly flying, they necessitate a large Aspect-Ratio wing. These slender structures are prone to large, non-linear deformations which further increase the unsteady nature of aerodynamic...
master thesis 2021
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Vojković, Tea (author)
There is increasing interest in the development of next-generation optimal controllers in the aerospace industry, focused on reducing aircraft environmental impact by mass reduction and enabling higher flight velocities for flexible wing structures. A key challenge in designing an optimal control system for this purpose is modeling the unsteady...
master thesis 2021
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Nijssen, T.M.J. (author), Kramer, O.J.I. (author), de Moel, P.J. (author), Rahman, J. (author), Kroon, J.P. (author), Berhanu, P. (author), Boek, E.S. (author), van der Hoek, J.P. (author), Padding, J.T. (author)
Liquid-solid fluidisation is frequently encountered in drinking water treatment processes, for instance in seeded crystallisation softening processes. For modest superficial fluid velocities, liquid–solid fluidisation systems are generally considered to be homogeneous, as reported in literature. However, during fluidisation experiments with...
journal article 2021
Searched for: subject%3A%22unsteadiness%22
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