3,360 research outputs found
A Novel Organic Rankine Cycle (ORC) for High Temperature Applications
Full text linkThe current experimental ORC setups for long-haul Heavy Duty Diesel Engines (HDDE) are not reaching the desired fuel savings within the expected costs. Pathways to improve ORC performance and cost-effectiveness remain a major challenge facing the automotive sector. This paper presents the conceptual overview and simulation results (using Aspen HYSYS) of a novel ORC especially tailored for high temperature heat sources (300-400°C) in truck applications. With a fundamental revision of the expansion and heat transfer characteristics, the advantage of the proposed novel ORC included an equivalent performance to the conventional ORC despite a 20% reduction in the total heat transfer area and a 40% reduction in the size of the expansion machine. This resulted in a 15% improvement in the Cost/kW value of the system, whilst offering 5.1% improvement in engine thermal efficiency at highway driving conditions
The North is another country. by Nicolas Rothwell
No full texttag=1 data=The North is another country. by Nicolas Rothwell
tag=2 data=Rothwell, Nicolas
tag=3 data=Australian Magazine,
tag=6 data=16/17 November 1996
tag=7 data=20-33.
tag=8 data=NT%TOURISM
tag=10 data=Worse, better, stranger, wilder, but above all different from the rest of the country. Continuing his journey of discovery across Australia's Top half the author stops over in Darwin to hear all the truths and whispers about the North.
tag=11 data=1996/2/8
tag=12 data=96/0316
tag=13 data=CABWorse, better, stranger, wilder, but above all different from the rest of the country. Continuing his journey of discovery across Australia's Top half the author stops over in Darwin to hear all the truths and whispers about the North
Break-up Mechanisms and Conditions for Vapour Slugs Within Mini-Channels
Full text linkIn the present investigation an enhanced Volume Of Fluid (VOF) based numerical simulation framework is applied for the conduction of parametric numerical simulations, aiming to investigate observed break-up phenomena of vapour slugs, within circular mini-channel branches of a hybrid thermosyphon / pulsating heat pipe device, during microgravity experiments. The simulation results identify three prevailing break-up regimes. The effect of fundamental controlling parameters in the resulting break-up characteristics is also examined. An entrainment of a liquid droplet at the trailing edge of the vapour slug, that is responsible for its subsequent “full” break-up, is identified from the simulations. Moreover, it is quite interesting that the value of the applied heat flux, does not seem to influence the break-up regime and its main characteristics
Accelerating Taylor bubbles within circular capillary channels:Break-up mechanisms and regimes
Full text linkIn the present paper, an enhanced Volume of Fluid model is applied for the conduction of parametric numerical simulations, to investigate break-up phenomena of accelerating, elongated, vapour bubbles, within circular mini-channels. The effect of fundamental controlling parameters in the resulting break-up characteristics is investigated. Four different series of parametric numerical simulations of isolated vapour bubbles within mini-channels are performed, examining the effects of the imposed pressure difference between the inlet and the outlet of the channel, the surface tension, the effect of the applied heat flux as well as the initial liquid film thickness between the bubbles and the channel, on the developed vapour/liquid interface dynamics. The overall dimensionless number ranges examined are 6.76 < We < 1474.7, 0.007 < Ca < 0.14, 694 < Re < 12541 and by introducing a modified Froude number in order to account for the flow acceleration, 1 < Fr* < 21.86. These dimensionless number ranges are selected in order to overlap with experimental observations in zero-gravity Pulsating Heat Pipe experiments that constitute the motivation for the present numerical investigation. The proposed simulation results identify three prevailing regimes. A “full break-up” regime, a “partial break-up” regime and a “no break-up” regime. The entrainment of liquid droplets at the trailing edge of the vapour slugs is in most cases responsible for their subsequent “full break-up”, into a leading and a trailing bubble, as it is identified from the numerical simulations. Moreover, the applied heat flux does not influence the resulting break-up regimes. Finally, these identified break-up regimes, are grouped together into a well-defined flow map with respect to the We and Fr* numbers.</p
Grace S. Fong, Herself an Author : Gender, Agency, and Writing in Late Imperial China, 2008
No full textZufferey Nicolas. Grace S. Fong, Herself an Author : Gender, Agency, and Writing in Late Imperial China, 2008. In: Études chinoises, n°28, 2009. Numéro spécial sur le droit chinois. pp. 243-247
New Necklaces: 400 Designs in Contemporary Jewellery
No full textAfter the successful New Rings and New Earrings, New Necklaces is the third book curated by jeweller and author Nicolas Estrada, from classic forms and materials to the most daring, experimental and surprising ideas, each of the 500 necklaces included in this book has something that makes it unique and relates strongly to today's social, cultural and artistic reality. With prefaces by German jeweller Julia Wild and Leo Caballero, owner of the Barcelona gallery Klimt 02, specialised in contemporary jewellers
How Did I Get to Princess Margaret? (And How Did I Get Her to the World Wide Web?)
No full textThe paper explores the growing use of
tools from the arts and humanities for investigation
and dissemination of social science research.
Emerging spaces for knowledge transfer, such as
the World Wide Web, are explored as outlets for
"performative social science". Questions of ethnics
and questions of evaluation which emerge from
performative social science and the use of new
technologies are discussed. Contemporary thinking
in aesthetics is explored to answer questions
of evaluation. The use of the Internet for productions
is proposed as supporting the collective
elaboration of meaning supported by Relational
Aesthetics.
One solution to the ethical problem of performing
the narrations of others is the use of the writer's
own story as autoethnography. The author queries
autoethnography's tendency to tell "sad" stories and
proposes an amusing story, exemplified by "The
One about Princess Margaret" (see Appendix).
The conclusion is reached that the free and open
environment of the Internet sidelines the usual
tediousness of academic publishing and begins to
explore new answers to questions posed about
the evaluation and ethics of performative social
science
Numerical investigation of liquid film instabilities and evaporation in confined oscillating slug-plug flows
Full text linkAn enhanced volume of fluid (VOF)-based numerical simulation framework that accounts for conjugate heat transfer between solid and two-phase flow regions and phase-change due to boiling/condensation, is utilised in order to investigate the effect of flow oscillation amplitude and frequency on the liquid film evaporation and instability formation in slug-plug flows within heated channels, in saturated flow boiling conditions. Various series of parametric numerical simulations are performed, for different values of flow oscillation amplitude and frequency for a variety of working fluids. For one of the working fluids two different channel diameters are also tested. The oscillations in each case are induced by applying an oscillating pressure boundary condition at the inlet of the channel, keeping the pressure constant at the outlet, after an initial period of constant pressure drop between the inlet and the outlet. Capillary ridges that are initiated at the liquid film, in the vicinity of the leading edge of the considered vapour slugs, are identified as a result of the imposed oscillations, which are translated in the form of capillary waves towards the rear end of the bubbles. It is shown that the formation frequency as well as the geometric characteristics of the generated ridges, are directly related to the corresponding frequency and amplitude of the induced flow oscillations. Furthermore, it is shown that in the initial stages of the bubble fate after the application of the oscillations liquid film evaporation is enhanced with the increase of the oscillation amplitude while it degrades as the frequency of the oscillation becomes higher. However, for large oscillation amplitudes and channel diameters, liquid jets penetrate into the elongated bubbles leading in a lot of cases to bubble break-up.</p
Reconversion d'une usine de locomotives en parc-technologique. Potsdam, RFA
No full textSAR-DCote: 1993.058Archive: Aucun document n'est archivé pour ce PDMGroupe de suivi: Snozzi Luigi; Pham Nicolas; Desvigne Miche
Numerical investigation on a combined loop heat pipe and graphite sheets cooling system for automotive applications
Full text linkAn innovative Battery Thermal Management System for a 3-cell Electric Vehicle module is proposed, involving Loop Heat Pipes and graphite sheets, with the particular aim of fast charging and reacting to automotive requirements. The design feasibility is verified through a Lumped Parameter Model, which has been validated comparing the data from an experimental demonstrator which included a copper/copper flat plate Loop Heat Pipe running ethanol. Results show that this solution is able to maintain the maximum temperature below 32°C after a 10 min fast charge cycle. System performance with a standard working fluid such as ethanol are compared with the system performance using a novel fluid, Novec™ 649, which has desirable features for the automotive industry, such as non-flammability, non-toxicity, below-zero freezing point and outstanding environmental properties (GWP = 1, ODP = 0). Nevertheless, comparison between the results with the two fluids reported no significant difference in thermal performance showing no contraindication in the use of the novel working fluid. Moreover, the model was used to estimate the effect of the Loop Heat Pipe building material, resulting in no sensible difference between the utilization of copper and aluminium, de facto justifying the choice of the lighter material for future applications
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