Searched for: subject:"jet"
(1 - 20 of 88)

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Rego, L. (author), Avallone, F. (author), Ragni, D. (author), Casalino, D. (author)
The link between jet-installation noise and the near-field flow features of the corresponding isolated jet is studied by means of lattice-Boltzmann numerical simulations. The computational set-up consists of a flat plate placed in proximity to a jet, replicating the interaction benchmark study carried out at NASA Glenn. Installation effects...
journal article 2020
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Prades, Lledó (author), Fabbri, Stefania (author), Dorado, Antonio D. (author), Gamisans, Xavier (author), Stoodley, Paul (author), Picioreanu, C. (author)
Experimental data showed that high-speed microsprays can effectively disrupt biofilms on their support substratum, producing a variety of dynamic reactions such as elongation, displacement, ripple formation, and fluidization. However, the mechanics underlying the impact of high-speed turbulent flows on biofilm structure is complex under such...
journal article 2020
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Martelli, E. (author), Saccoccio, L. (author), Ciottoli, P. P. (author), Tinney, C. E. (author), Baars, Woutijn (author), Bernardini, M. (author)
A delayed detached eddy simulation of an overexpanded nozzle flow with shock-induced separation is carried out at a Reynolds number of, based on nozzle throat diameter and stagnation chamber properties. In this flow, self-sustained shock oscillations induce local unsteady loads on the nozzle wall as well as global off-axis forces. Despite...
journal article 2020
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Cascioli, E. (author), Buckingham, S. (author), Keijers, S. (author), Tichelen, K. Van (author), Kenjeres, S. (author)
In the present work, we combine experiments and numerical simulations of a planar jet with heated co-flow with medium (air) and low-Prandtl (He-Xe gas mixture) fluids. Jets are recognized as representative test cases to be investigated in large components of pool-type liquid metal-cooled nuclear systems, like the Multi-purpose hYbrid Research...
journal article 2020
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Silva Capaz, R. (author), Posada Duque, J.A. (author), Osseweijer, P. (author), Seabra, Joaquim E.A. (author)
Although the potential of Alternative Jet Fuels (AJF) to reduce greenhouse gases (GHG) emissions has been widely reported upon in the literature, there are still discrepancies among the results. These may be due to the different GHG accounting methods, including those used by different Low-Carbon Policies (LCPs). To have a clearer...
journal article 2020
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Nokhrina, E. E. (author), Gurvits, L. (author), Beskin, V. S. (author), Nakamura, M. (author), Asada, K. (author), Hada, K. (author)
We propose a new method of estimating the mass of a supermassive black hole residing in the centre of an active galaxy. The active galaxy M87 offers a convenient test case for the method due to the existence of a large amount of observational data on the jet and ambient environment properties in the central area of the object. We suggest that...
journal article 2019
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Ypma, S.L. (author), Brüggemann, N. (author), Georgiou, S. (author), Spence, P. (author), Dijkstra, H. A. (author), Pietrzak, J.D. (author), Katsman, C.A. (author)
The pathways and watermass transformation of the North Icelandic Irminger Current (NIIC) in the Nordic Seas are investigated by tracing the NIIC watermass in two ocean circulation models: the Modular Ocean Model (MOM) and the Parallel Ocean Program (POP). The two simulations use identical atmospheric forcing and have a horizontal resolution of 0...
journal article 2019
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Bakker, R.R. (author), Barnhoorn, A. (author)
We study the potential formation damage effects due to radial jet drilling on Bentheim sandstone, a homogeneous sandstone that is well established in terms of mechanical properties and widely used as reservoir analogue. We quantify how properties degrade with distance from a jetted hole on μm scale (porosity) and cm scale (compressive, tensile...
journal article 2019
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Aalbers, Albert B. (author), Hoving, J.S. (author)
Ships at sea will encounter deck wetness events that usually are just annoying and rarely lead to damage. Discomfort is experienced by spray, as it is limiting view and hampering deck work. In freezing conditions, deck wetting will lead to icing. This study is a continuation of publications regarding the development of a marine icing model...
conference paper 2019
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Broekema, Y.B. (author), Labeur, R.J. (author), Uijttewaal, W.S.J. (author)
Flow separation and its control have been the subject of intensive research for decades. Flow separation occurs when the boundary layer loses contact with the associated confining wall, which is usually caused by a pressure gradient acting against the local flow direction. Numerous strategies exist to control flow separation, and in this...
journal article 2019
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Zong, H. (author), Chiatto, Matteo (author), Kotsonis, M. (author), de Luca, Luigi (author)
The plasma synthetic jet actuator (PSJA), also named as sparkjet actuator, is a special type of zero-net mass flux actuator, driven thermodynamically by pulsed arc/spark discharge. Compared to widely investigated mechanical synthetic jet actuators driven by vibrating diaphragms or oscillating pistons, PSJAs exhibit the unique capability of...
review 2018
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Zong, H. (author)
In the last few decades, active flow control (AFC) technology has been developed to minimize the aerodynamic drag of transportation vehicles and maximize the propulsion efficiency of thermodynamic engines. The key of this technology is the actuators. Among all the actuators that have been proposed (i.e. fluidic, moving object, or plasma-based),...
doctoral thesis 2018
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Broekema, Y.B. (author), Labeur, R.J. (author), Uijttewaal, W.S.J. (author)
Scour in the vicinity of a hydraulic structure may compromise its geotechnical stability or that of nearby structures. Much fundamental research has been dedicated to the understanding and prediction of these processes, in order to enable the efficient design of mitigation measures. While most of these efforts consider laterally uniform flows,...
journal article 2018
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van Hout, R.L.H. (author), Eisma, H.E. (author), Elsinga, G.E. (author), Westerweel, J. (author)
In many applications, finite-sized particles are immersed in a turbulent boundary layer (TBL) and it is of interest to study wall effects on the instantaneous shedding of turbulence structures and associated mean velocity and Reynolds stress distributions. Here, 3D flow field dynamics in the wake of a prototypical, small sphere (D+=50, 692&lt...
journal article 2018
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Jahangir, S. (author), Hogendoorn, W.J. (author), Poelma, C. (author)
Partial cavitation dynamics in an axisymmetric converging-diverging nozzle are investigated experimentally. Shadowgraphy is used to visualize and analyze different cavitation regimes. These regimes are generated by changing the global static pressure and flow velocity independently. Cloud cavitation is the most interesting and complex regime,...
journal article 2018
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Guariglia, Daniel (author), Rubio Carpio, A. (author), Schram, Christophe (author)
Shock-cell noise occurs in aero-engines when the nozzle exhaust is supersonic and shock-cells are present in the jet. In commercial turbofan engines, at cruise, the secondary flow is often supersonic underexpanded, with the formation of annular shock-cells in the jet and consequent onset of shock-cell noise. This paper aims at describing the...
journal article 2018
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Augusto Viviani Perpignan, A.A.V. (author), Gangoli Rao, A. (author), Roekaerts, D.J.E.M. (author)
Since its discovery, the Flameless Combustion (FC) regime has been seen as a promising alternative combustion technique to reduce pollutant emissions of gas turbine engines. This combustion mode is often characterized by well-distributed reaction zones, which can potentially decrease temperature gradients, acoustic oscillations and,...
review 2018
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Perçin, M. (author), Vanierschot, M. (author), van Oudheusden, B.W. (author)
In this paper, we investigate the flow structures and pressure fields of a free annular swirling jet flow undergoing vortex breakdown. The flow field is analyzed by means of time-resolved tomographic particle image velocimetry measurements, which enable the reconstruction of the three-dimensional time-resolved pressure fields using the...
journal article 2017
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Zong, H. (author), Kotsonis, M. (author)
The performance of a two–electrode plasma synthetic jet actuator (PSJA) is investigated for a wide range of dimensionless actuation frequencies (f*) using high-speed phase-locked Particle Imaging Velocimetry (PIV) measurements. The jet-induced velocity fields in the axisymmetric plane are measured during both...
journal article 2017
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Litvinov, D.A. (author), Bach, U. (author), Bartel, N. (author), Belousov, K.G. (author), Bietenholz, M. (author), Biriukov, A.V. (author), Cimo, G (author), Duev, D. A. (author), Gurvits, L. (author), Gusev, A.V. (author), Haas, R (author), Kauts, V.L. (author), Kanevsky, B.Z. (author), Kovalenko, A.V. (author), Kronschnabl, G (author), Kulagin, V.V. (author), Lindqvist, Maria (author), Molera Calves, G (author), Neidhardt, A. (author), Plotz, C. (author), Pogrebenko, S. V. (author), Porayko, N.K. (author), Rudenko, V.N. (author), Sokolovsky, K. V. (author), Smirnov, A.I. (author), Stepanyants, V.A. (author), Yang, J. (author), Zakhvatkin, M.V. (author)
A test of a cornerstone of general relativity, the gravitational redshift effect, is currently being conducted with the RadioAstron spacecraft, which is on a highly eccentric orbit around Earth. Using ground radio telescopes to record the spacecraft signal, synchronized to its ultra-stable on-board H-maser, we can probe the varying flow of time...
conference paper 2016
Searched for: subject:"jet"
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