Searched for: subject%3A%22PIV%22
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van Meerkerk, M. (author), Poelma, C. (author), Hofland, B. (author), Westerweel, J. (author)
We present an experimental study on the gas flow field development over a plunging breaking wave prior to impact on a vertical wall. The variability of wave impact pressure over repeated measurements is well known (Bagnold, 1939). The formation of instabilities on the wave crest are postulated to be the main source of impact pressure variability...
journal article 2022
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PATIL, YUGANDHAR VIJAYKUMAR (author)
Vertical Axis Wind Turbine (VAWT) operation is characterized by complex and unsteady three-dimensional fluid dynamics, which presents considerable challenges. One of the crucial points to understand is the complex interaction between rotor, inflow, and wake systems. If we can demonstrate its effectiveness in the complex flow/inflow conditions,...
master thesis 2021
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Jakhar, Rishabh (author)
The increasing importance of drag reduction in commercial vehicles, traditionally motivated by rising energy costs, and more recently accelerated through policymaking in a bid to reduce emissions, has resulted in the development of increasingly sophisticated add-on aerodynamic devices for the semi-trailer. Of these devices, the greatest uptake...
master thesis 2021
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Hartog, Friso (author)
Turbulent drag is the largest source of fuel consumption in aviation and forms a significant contribution to climate warming. Recent numerical studies have suggested the ability of surfaces with streamwise-preferential permeability to reduce turbulent friction, and a theoretical framework behind the working mechanism has been proposed. This work...
master thesis 2021
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Solergibert I Travé, Oriol (author)
Inspired by the dolphin skin, compliant coatings have been researched as a passive flow control solution to reduce drag. Both successful and drag-increasing experiments can be found in the literature. However, the mechanism is not well understood neither the combination of surface properties and flow conditions that yield a drag reduction. At...
master thesis 2021
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Tiel, Roos (author)
The diffuser stern is part of a design concept from Damen and the TU delft: the interceptor diffuser. This concept aims to improve the seakeeping behavior of fast ships in waves. With PIV measurements, a contribution to the development of the diffuser stern is made. The flow acceleration and detachment are studied, and a comparison with a CFD...
master thesis 2021
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Barsom, Bavly (author)
Supersonic intakes are essential in assuring proper combustion for operating ramjet engines on cruise missiles. However, due to increasing threats and a rapidly changing service environment, today's intakes do not fit anymore to comply with the new set of requirements to tackle the above challenges. Therefore, a novel supersonic intake design is...
master thesis 2021
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Bouman, Gijs (author)
In this thesis, the resistance of a single degree of freedom liner is investigated experimentally. Semi-empirical resistance modelling fails at higher Mach numbers (M<sub>0</sub>&gt;0.3) and sound pressure levels (SPL&gt;130dB), and experimental work is missing in these conditions. An experiment combining in-situ impedance measurements and phase...
master thesis 2021
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Sem, Jacopo (author)
The reduction of turbulent skin-friction drag has the potential to generate numerous societal benefits. In large-scale industrial applications, the largest share of energy consumption goes into overcoming the friction drag produced by turbulent boundary layers formed on the outside wall. Estimates assess that over 50% of the total fuel burn is...
master thesis 2021
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Vermeijlen, Simon (author)
Swirl-stabilised hydrogen combustion has great potential in the aviation industry since emissions can be significantly reduced compared to fossil fuels. However, a major drawback is a high proneness to flashback. This could be overcome with non-swirling axial air injection (AAI) on the centre-line of the mixing tube. The effect of this concept...
master thesis 2021
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van Meerkerk, M. (author)
The prospect of stricter national and international emission standards for the shipping industry are a driving force in the search for alternative shipping fuels, such as liquefied natural gas (LNG). However, new challenges arise with the widespread use of LNG. For example, there is a desire to use LNG cargo containment...
doctoral thesis 2021
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Engler Faleiros, D. (author)
Particle Image Velocimetry (PIV) relies upon the introduction of particle tracers that scatter sufficient light and follow the flow accurately. The use of submillimetre helium-filled soap bubbles (HFSB) as flow tracers for PIV is investigated for the purpose of enabling velocity measurements in large-scale industrial wind tunnels. That soap...
doctoral thesis 2021
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de Koning, Coert (author)
To achieve delay of laminar-to-turbulent transition of boundary layers, the application of acoustic metamaterial concepts is investigated. This is done analytically, numerically and experimentally by studying the interaction between a Helmholtz resonator and a TS wave. A Helmholtz resonator can serve as a meta-atom in a metamaterial. The desired...
master thesis 2021
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Dacome, Giulio (author)
The development of air-breathing propulsion systems as a mean to propel high-altitude high-speed transport and single-stage-to-orbit (SSTO) vehicles promises to be a viable alternative to chemical rocket propulsion. In order to enhance mixing, an oblique shock wave is introduced into the combustion chamber as a source of baroclinic vorticity as...
master thesis 2021
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Saredi, E. (author), Tumuluru Ramesh, Nikhilesh (author), Sciacchitano, A. (author), Scarano, F. (author)
State observer techniques are investigated for the assimilation of three-dimensional velocity measurements into computational fluid dynamics simulations based on Reynolds-averaged Navier–Stokes (RANS) equations. The method relies on a forcing term, or observer, in the momentum equation, stemming from the difference between the computed velocity...
journal article 2021
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Guo, Y. (author), Jia, W. (author), Markine, V.L. (author), Jing, Guoqing (author)
Ballast rheology is a phenomenon that describes movements of ballast particles due to the discrete nature, which eventually leads to the ballast bed fluid deformation after a long-time service. In most cases, ballast rheology is the main reason of track irregularity that leads to some track defects, e.g., hanging sleeper and mud spots....
journal article 2021
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Spoelstra, A.M.C.M.G. (author), Sciacchitano, A. (author), Scarano, F. (author), Mahalingesh, Nikhil (author)
The aerodynamic drag of a trailing cyclists in a tandem formation is investigated at different lateral and longitudinal separations. A Ring of Fire (RoF) experiment is conducted at the Tom Dumoulin bike park of Sittard-Geleen in the Netherlands. The method is based on stereoscopic Particle Image Velocimetry (Stereo-PIV) measurements followed...
journal article 2021
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Jux, C. (author), Sciacchitano, A. (author), Scarano, F. (author)
The aerodynamic characteristics of a modern road cycling wheel in crosswind are studied through force measurements and 3D velocimetry in TU Delft’s Open Jet Facility. The performance of the 62 mm deep rim is evaluated for two tire profiles, and yaw angles up to 20◦ . All measurements are executed at 12.5 m/s (45 km/h) freestream- and wheel...
conference paper 2021
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Bakker, W. (author), Hofland, B. (author), de Almeida Sousa, E. (author), Oldenziel, G. (author), Overmars, E.F.J. (author)
In this paper the development of a high-power pulsed LED line light and its use to apply particle image velocimetry (PIV) during wave impact measurements are described. An electrical circuit that generates high-current pulses is designed and built, which is used to overdrive a number of commercially available LEDs. The limit for this...
journal article 2021
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Mertens, C. (author), Sciacchitano, A. (author), van Oudheusden, B.W. (author), Sodja, J. (author)
The structural motion and unsteady aerodynamic loads of a pitching airfoil model that features an actuated trailing edge flap are determined experimentally using a single measurement and data processing system. This integrated approach provides an alternative to the coordinated use of multiple measurement systems for simultaneous position and...
journal article 2021
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