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Chakkingal, M. (author), Kenjeres, S. (author), Ataei Dadavi, I. (author), Tummers, M.J. (author), Kleijn, C.R. (author)We report numerical simulations of natural convection and conjugate heat transfer in a differentially heated cubical cavity packed with relatively large hydrogel beads (d/L=0.2) in a Simple Cubic Packing configuration. We study the influence of a spatially non-uniform, sinusoidally varying, wall temperature on the local flow and heat transfer...journal article 2020
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Kenjeres, S. (author), Fornalik-Wajs, E. (author), Wrobel, W. (author), Szmyd, J. S. (author)The present study addresses the detailed numerical analysis of the flow and heat transfer of a paramagnetic fluid inside a differentially heated cubical box and subjected to a strong non-uniform magnetic field. Two different heating scenarios are considered regarding an initial thermal stratification: unstable (heated from the bottom) and...journal article 2020
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Ranjan, R. (author), Ayas, C. (author), Langelaar, Matthijs (author), van Keulen, A. (author)The powder bed fusion (PBF) process is a type of Additive Manufacturing (AM) technique which enables fabrication of highly complex geometries with unprecedented design freedom. However, PBF still suffers from manufacturing constraints which, if overlooked, can cause various types of defects in the final part. One such constraint is the local...journal article 2020
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Kanawade, Kunal (author)In nuclear industry applications, from design and safety aspects, it is important to predict the flow and heat transfer. The passive cooling systems, one of the robust cooling systems in the nuclear design are based on natural convections. In the RANS approach, non-linear unknown heat flux term has to be closed by appropriate model for accurate...master thesis 2019
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Berthet, Kevin (author)The widely used cone penetration test (CPT) allows in-situ measurements of soil behaviour during continuous penetration. The traditional sensors incorporated in a cone penetrometer are for measuring cone resistance, sleeve friction, pore pressure, and inclination. Many supplementary sensors have been studied and tried in research settings and in...master thesis 2019
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Guzmán Sáenz, Francisco (author)The construction, operation and maintenance of buildings consume more than 40% of primary energy in most countries. Out of this 40%, a large portion is related to the operational phase involving heat losses through a buildings envelope. To reduce this loss, several materials have been developed to reduce the thermal transmittance through a...master thesis 2019
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Bijvoet, Bastiaan (author)In industry, fired heaters are used to heat process fluids and to generate steam. The efficiency of these devices is increased with air preheating. Gnerally, the flow through the air preheaters is driven by a centrifugal fan, via forced draft. Through a widening transition duct (large angle diffuser), air flows from the fan towards the air...master thesis 2019
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Govaert, Thomas (author)The German Aerospace Centre (DLR) has in the past years been performing test runs with their experimental sub-scale combustion chambers to measure and investigate the effects of unstable combustion. Some of these investigations are focused on the heat flux to the chamber walls, changes in which can cause a significant shift in chamber wall...master thesis 2019
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Biesheuvel, Bas (author)TechnipFMC is pushing innovations to reduce the emissions of ethylene plants separations. This development is also driven by customer demands. They face increasingly strict legislation on \ce{CO2} emissions. Separation in distillation columns is one of the major energy intensive unit operations in an ethylene plant, and increasing their...master thesis 2019
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Hoogerbrugge, Ary-Jan (author)In modern ASML machines optical components play an important role in the lithography process. EUV light is transported from the source to wafer by reflective optics. These mirrors are subjected to large thermal loading, as a large portion of the reflected light is absorbed in the mirror structure. The portion of the absorbed light is strongly...master thesis 2019
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Ataei Dadavi, I. (author), Chakkingal, M. (author), Kenjeres, S. (author), Kleijn, C.R. (author), Tummers, M.J. (author)This paper reports on an experimental study of natural convection in an enclosure that is heated at the bottom and cooled at the top, filled with a packed bed of relatively large solid spheres. Nusselt numbers were measured for various sphere conductivities, spheres sizes and sphere packings for Rayleigh numbers varying between 10<sup>7</sup>...journal article 2019
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Wang, M. (author), He, Lijuan (author), Infante Ferreira, C.A. (author)Unfavorable transport properties have always been pointed out as the key factors that hinder the application of ammonia/ionic liquids (NH <sub>3</sub> /ILs) in absorption cycles, while heat and mass transfer of these new fluids in components have been rarely reported. In this study, a corrugated plate heat exchanger is selected as the...journal article 2019
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Peeters, J.W.R. (author), Rohde, M. (author)A new friction-heat transfer analogy for the prediction of heat transfer to turbulent fluids at supercritical pressure is presented. This analogy is based on the observation that the predominent events that determine the turbulent heat flux known as hot ejections and cold sweeps have different thermophysical properties. This observation is...journal article 2019
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Peeters, J.W.R. (author), Sandham, N. D. (author)It is well known that rough surfaces affect turbulent flows significantly. How such surfaces affect turbulent heat transfer is less well understood. To gain more insight, we have performed a series of direct numerical simulations of turbulent heat transfer in a channel flow with grit-blasted surfaces. An immersed boundary method is used to...journal article 2019
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Toa, X. (author), Infante Ferreira, C.A. (author)The corrugation channels of plate heat exchangers enhance the heat transfer and complicate the prediction of heat transfer coefficients and frictional pressure drop. This paper reviews the heat transfer and frictional pressure drop correlations for condensation in plate heat exchangers, and classifies the correlations into basic forms. An...review 2019
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Hussien, Ahmed A. (author), Abdullah, Mohd Z. (author), Yusop, Nadiahnor Md (author), Al-Kouz, Wael (author), Mahmoudi, Ebrahim (author), Mehrali, M. (author)Massive improvements in the thermophysical properties of nanofluids over conventional fluids have led to the rapid evolution of using multiwalled carbon nanotubes (MWCNTs) and graphene nanoplatelets (GNPs) in the field of heat transfer. In this study, the heat transfer and entropy generation abilities of MWCNTs/GNPs hybrid nanofluids were...journal article 2019
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Tummers, M.J. (author), Steunebrink, M. (author)This paper reports on an experimental study of the effects of surface roughness on the flow and heat transfer in cubical Rayleigh-Bénard convection cells for Rayleigh numbers between 10<sup>7</sup> and 10<sup>10</sup>. In the rough cells the top and bottom surfaces are equipped with square arrays of copper cubes. In line with other studies,...journal article 2019
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Silvestri, S. (author), Pecnik, Rene (author)We implemented a fast Reciprocal Monte Carlo algorithm to accurately solve radiative heat transfer in turbulent flows of non-grey participating media that can be coupled to fully resolved turbulent flows, namely to Direct Numerical Simulation (DNS). The spectrally varying absorption coefficient is treated in a narrow-band fashion with a...journal article 2019
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Rasooli, A. (author), Itard, L.C.M. (author)Accurate determination of walls' thermo-physical characteristics is a necessity for execution of energy conservation strategies in existing buildings. In practice, such data is not available because the current determination methods are time expensive and therefore rarely used. Based on the theory of Response Factors, a rapid transient in...journal article 2019
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Luna-Triguero, Azahara (author), Sławek, A. (author), Huinink, H.P. (author), Vlugt, T.J.H. (author), Poursaeidesfahani, A. (author), Vicent-Luna, J.M. (author), Calero, S. (author)According to the European Commission, in 2016 the residential sector represented 25.4% of the final energy consumption. Heating and cooling in EU households account for 69.1% of the total energy consumption. The fraction of 84% for heating and cooling is still generated from fossil fuels, and only 16% is generated from renewable energy. To...journal article 2019