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Channel Flows in Plate Heat Exchangers with the Aid of Particle Tracking Velocimetry

Open Journal of Fluid Dynamics 2024年第3期14卷 163-183页

作者： Felipe José dos santos leonel Edward Beckedorff Kleber Vieira de Paiva Jorge Luiz Goes Oliveira petrobras—petróleo brasileiro s.a. Rio de Janeiro Brazil Institute of Fluid Mechanics.a.d Heat Transfer Technische Universität Wien Vienna Austria Department of Mobility Engineering Federal University of Santa Catarina Joinville Brazil

Channel flows of Plate Heat Exchangers (PHEs) were assessed by experiments with three different chevron angle arrangements in turbulent regime. Two chevron angles were selected to assess low and high pressure drop channels, besides.a.third mixed configuration as to achieve in-between results regarding hydraulic performance. Friction factor correlations were provided with the channel Reynolds number ranging from 1175 to 8325. Two-dimensional (2D) mean velocity field was obtained by Particle Tracking Velocimetry (PTV) with Reynolds number equal to 3450. To the best of our knowledge, this is the first experimental study that quantified the complete 2D velocity field of a typical PHE channel. This value allowed comparison with literature results of Plate and shell Heat Exchanger (PsHE) channels with the same Reynolds number. PsHE mean velocity field is highly heterogeneous.a. compared to the one obtained for PHE channels. Peak velocity magnitude in the PsHE center is 50% higher than its bulk velocity, whereas this value is only 15% higher in the PHE center. Pressure drop in PHE mixed channels cannot be approximated by averaging chevron angles: furrow flow prevailed in the specified conditions. The axial velocity is.a.ymmetric regarding the vertical plane. smooth streamlines prevail in the channel inlet. Recirculation zones.a. the channel exit affect pipe flow in the manifold outlet with swirling flow structures. The neces.a.y length to obtain fully developed pipe flow at the channel outlet was estimated. significant velocity components occur in the distribution areas.a.d can limit the heat exchanger performance. The results reported herein are essential to unders.a.d how the PHE channel geometry affects the velocity field and, therefore, local heat transfer and dissipation processes.

关键词： PHE PTV PsHE Friction Factor Chevron

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CFD predictions for hazardous.a.ea classification

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Chinese Journal of Chemical Engineering 2019年第1期27卷 21-31页

作者： Andrey Oliveira de souza Aurélio Moreira Luiz Ant?nio Tavernard Pereira Neto Ant?nio Carlos Brandao de Araujo Heleno Bispo da silva sidinei Kebler da silva Jose Jailson Nicacio Alves Federal Institute of Education Science and Technology of Paraiba petrobras-petróleo brasileiro s.a. Federal University of Campina Grande

This study aimed to describe a Computational Fluid Dynamics(CFD) procedure using the ANsYs CFX software 16.1 and Design of Experiments for the determination of volume and extension of explosive atmospheres due to fugitive emissions of flammable *** multidimensional s.a.istical sampling technique Latin Hypercube was used, which defined 100 simulations of random methane gas leak *** CFD model proved to be robust in predicting the extension and volume of the explosive atmosphere for orifice diameters from 0.1 to2.5 mm, pressure from 0.1 MPa to 12 MPa and temperatures from 0 ℃ to 400 ℃.It was found that the calculation domain must be parameterized 8 m in length for each millimeter of the diameter of the source of release to ensure the *** order not to lose precision for very s.a.l diameters, the mesh was parameterized with 50 elements.a.ong the orifice *** was proved that gravity does not influence the extension and volume of the explosive atmosphere at sonic *** deviation from the ideal gas behavior in the reservoir,achieved by applying the s.a.e–Redlich–Kwong equation of s.a.e, also has not significantly influenced the extension and volume of the explosive *** results showed that the size of the explosive atmosphere varies directly with the diameter of the source emission and reservoir pressure, and inversely with the temperature of the *** diameter of the source is the parameter that has the major effect on the extension of the explosive atmosphere, followed by the pressure and lastly the temperature of the reservoir.

关键词： Computational Fluid Dynamics Computer simulation safety Fugitive emissions Classified area Flammable gas cloud

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Experimental evidence of pressure effects on spinel dissolution and peridotite serpentinization kinetics under s.a.low hydrothermal conditions

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Geoscience Frontiers 2024年第2期15卷 236-250页

作者： Yuri de Melo Portella Rommulo Vieira Conceição Tiago Abreu siqueira Lucas Bonan Gomes Rodrigo sebastian Igles.a. Programa de Pós-Graduação em Geociências(PPGGEO) Universidade Federal do Rio Grande do SulPorto AlegreBrazil petrobras–petróleo brasileiro s.a. Avenida Henrique Valadares 28CentroRio de Janeiro(RJ)20231-030Brazil Instituto do petróleo e dos Recursos Naturais-PUCRs–Pontifícia Universidade Católica do Rio Grande do sul 90619-900Porto AlegreBrazil Universidade Federal do Rio Grande do sul Instituto de GeociênciasLaboratório de Difratometria de Raios XPorto AlegreBrazil Escola Politécnica–PUCRs-Pontifícia Universidade Católica do Rio Grande do sul 90619-900 Porto AlegreBrazil

serpentinization reactions.a.e paramount to unders.a.d hydro-geothermal activity near plate boundaries.a.d mafic–ultramafic massifs.a. well as fluid and element transfer between the Earth’s mantle and ***,fluid-rock element exchange and serpentinization kinetics under s.a.low hydrothermal conditions is still largely *** we present two cons.a.t temperature(230℃)time-series of natural peridotite(77.5%olivine;13.7%ens.a.ite;6.8%diopside;2%spinel)serpentinization experiments.a. 13.4 MPa;and 20.7 ***-enriched lizardite was the main secondary mineral in all runs.a.ter olivine(olv)and orthopyroxene(opx)serpentinization(without any detectable brucite,talc or magnetite),while primary spinel and diopside partially dissolved during the *** serpentinization s.a.es comprises intrinsically coupled reactions between olivine and ens.a.ite,as.a. and si are progressively transferred from orthopyroxene-derived to olivine-derived serpentine,while the opposite is true for Mg and Fe,with homogenization of serpentines compositions.a.ter 40 *** Ni/Cr ratios of serpentines,however,remain diagnostic of the respective primary *** average serpentine content indicates fast serpentinization rates of 0.55 wt.%·day^(-1)(0.26 mmol·day^(-1))and 0.26 wt.%·day^(-1)(0.13 mmol·day^(-1))at 13.4 and 20.7 MPa,*** 2x faster serpentinization kinetics.a. lower pressure is likely linked to enhanced spinel dissolution leading to one order of magnitude higher available Al,which accelerates olivine serpentinization while delays orthopyroxene ***,time-dependent increase in solid products masses suggests rock volume expands linearly 0.37%±0.01%per serpentine wt.%independently of *** balance constrains suggests olv:opx react at~5:2 and~3:2 M ratios,resulting in si-deficient and si-saturated serpentines.a. the end of the low-pressure series(13.4 MPa)and high-pressure series(20.7 MPa),***

关键词： serpentine Volume expansion serpentinization fluids Lost City hydrothermal field serpentinite-hosted hydrothermal systems Hydrogen(H_(2))generation

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Channel estimation-based time-frequency neural network for post-equalization in underwater visible light communication

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Chinese Optics Letters 2024年第6期22卷 116-122页

作者： Haoyu Zhang Li Yao Chaoxu Chen Yuan Wei Chao shen Jianyang shi Junwen Zhang Ziwei Li Nan Chi Key Laboratory for Information science of Electromagnetic Waves(MoE) Department of Communication Science and EngineeringSchool of Information Science and TechnologyFudan UniversityShanghai 200433China s.a.ghai CIC of leo satellite Communication Technology Fudan UniversityShanghai 200433China s.a.ghai ERC of leo satellite Communication and Application Fudan UniversityShanghai 200433China

This Letter proposes.a.post-equalizer for underwater visible light communication(UVLC) systems that combines channel estimation and joint time-frequency analysis, named channel-estimation-based bandpass variable-order time-frequency network(CBV-TFNet). By utilizing a bandpass variable-order loss function with communication prior knowledge, CBVTFNet enhances communication performance and training s.a.ility. It enables lightweight implementation and faster convergence through a channel estimation-based mask. The superior performance of the proposed equalization method over Volterra and deep neural network(DNN)-based methods has been studied experimentally. Using bit-power loading discrete multitone (DMT) modulation, the proposed method achieves.a.transmission bitrate of 4.956 Gbps through a 1.2 m underwater channel utilizing only 38.15% of real multiplication calculations compared to the DNN equalizer and achieving a bitrate gain of440 Mbps.a.d a significantly larger dynamic range over the LMs-Volterra equalizer. Results highlight CBV-TFNet's potential for future post-equalization in UVLC systems.

关键词： underwater visible light communication channel estimation post-equalizer neural network

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Multi-Criteria Wildfire Risk Hazard Assessment in GIs Environment: Projection for the Future and Impact on REs Projects Ins.a.lation Planning

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Journal of Geoscience and Environment Protection 2024年第5期12卷 242-265页

作者： Aggelos Pallikarakis Flora Kons.a.topoulou EXERGIA s.a. Climate Change Consultants Athens Greece

It is.a.arming for the fact that Wildfires number, severity and consequently impact have significantly increased during the last years, an aftermath of the Climate Change. One of the most affected areas worldwide is Mediterranean, due to the unique combination of its type of vegetation and demanding climatic conditions. This res.a.ch is focused on the Region of Epirus in Greece, an area with significant natural vegetation and a range of geomorphological aspects. In order to estimate the Wildfire Risk Hazard, several factors have been used: geomorphological (slope, aspect, elevation, TWI, Hydrographic network), social (settlements.a.d landfils, roads, overhead lines.a.d subs.a.ions), environmental (land cover) and climatic (Fire Weather Index). Through a multi-criteria decision analysis (MCDA) and an analytic hierarchy process (AHP) in a GIs environment, the Wildfire Risk Hazard has been estimated not only for current conditions but also for future projections for the near future (2031-2060) and the far future (2071-2100). The selected case study includes the potential impact of the Wildfires to the ins.a.led (or targeted to be ins.a.led) REs projects in the studied region.

关键词： REs Projects Greece Epirus Analytic Hierarchy Process Multi-Criteria Decision Analysis

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Geos.a.istical seismic inversion and 3D modelling of metric flow units,porosity and permeability in Brazilian presalt reservoir

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petroleum science 2024年第3期21卷 1699-1718页

作者： Rodrigo Penna Wagner Moreira Lupinacci Exploratory Interpretation and Reservoir Characterization Group(GIECAR) Department of Geology and GeophysicsUniversidade Federal FluminenseNiteroiRJ24210-346Brazil petrobras Rio de JaneiroRJ20031-912Brazil

Flow units(FU)rock typing is.a.common technique for characterizing reservoir flow behavior,producing reliable porosity and permeability estimation even in complex geological ***,the lateral extrapolation of FU away from the well into the whole reservoir grid is commonly a difficult task and using the seismic data as constraints is rarely a subject of *** paper proposes.a.workflow to generate numerous possible 3D volumes of flow units,porosity and permeability below the seismic resolution limit,respecting the available seismic data at larger *** methodology is used in the Mero Field,a Brazilian presalt carbonate reservoir located in the santos Basin,who presents.a.complex and heterogenic geological setting with different sedimentological processes.a.d diagenetic *** generated metric flow units using the conventional core analysis.a.d transposed to the well log ***,given a Markov chain Monte Carlo algorithm,the seismic data and the well log s.a.istics,we simulated acoustic impedance,decametric flow units(DFU),metric flow units(MFU),porosity and permeability volumes in the metric *** aim is to estimate a minimum amount of MFU able to calculate realistic scenarios porosity and permeability scenarios,without losing the seismic lateral *** other words,every porosity and permeability volume simulated produces.a.synthetic seismic that match the real seismic of the area,even in the metric *** achieved 3D results represent a high-resolution fluid flow reservoir modelling considering the lateral control of the seismic during the process.a.d can be directly incorporated in the dynamic characterization workflow.

关键词： Flowunits Geos.a.istical inversion Presalt reservoir 3D reservoir modelling petrophysical modelling

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Demonstration of radar-aided flexible communication in a photonics-based W-band distributed integrated sensing and communication system for 6G

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Chinese Optics Letters 2024年第4期22卷 119-124页

作者：贾俊连董博宇陶理施剑阳迟楠张俊文 Key Laboratory of EMW Information(MoE) Fudan UniversityShanghai 200433China s.a.ghai ERC of leo satellite Communication and Applications Shanghai CIC of LEO Satellite Communication TechnologyShanghai 200433China science and Technology on Electromagnetic Compatibility Laboratory China Ship Development and Design CentreWuhan 430000China Peng Cheng Laboratory Shenzhen 518055China

This paper experimentally demonstrates.a.distributed photonics-based W-band integrated sensing and communication(IsAC) system, in which radar sensing can aid the communication links in alignment and data rate estimation. As.a.proof-of-concept, the IsAC system locates the users, guides the alignment, and sets.a.communication link with the estimated highest data rate. A peak net data rate of 68.6 Gbit/s.a.d a target sensing with a less-than-1-cm error and a sub-2-cm resolution have been tested over a 10-km fiber and a 1.15-m free s.a.e transmission in the photonics-based W-band IsAC system. The achievable net data rates of the users.a. different locations estimated by sensing are experimentally verified.

关键词： integrated sensing and communication photonics.a.ded technique W-band radar-aided flexible communication

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Hydrocarbon indication in Rio Bonito Formation sandstone:Implication for CO_(2)storage in são Paulo,Brazil

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Energy Geoscience 2024年第1期5卷 331-341页

作者： Richardson M.Abraham-A Haline V.Rocha saulo B.de Oliveira Colombo C.G.Tassinarri Orlando C.da silva Institute of Energy and Environment University of São PauloSão PauloBrazil Res.a.ch Centre for Greenhouse Gas Innovation University of São PauloSão PauloBrazil

são Paulo s.a.e has witnessed CO_(2)storage-based investigations considering the availability of suitable geologic structures.a.d proximity to primary CO_(2)source sinks related to bioenergy and carbon capture and storage(BECCs)*** current study presents the hydrocarbon viability evaluations.a.d CO_(2)storage prospects,focusing on the sandstone units of the Rio Bonito *** objective is to apply petrophysical evaluations with geochemical inputs in predicting future hydrocarbon(gas)production to boost CO_(2)storage within the study *** study used data from eleven wells with associated wireline logs(gamma ray,resistivity,density,neutron,and sonic)to predict potential hydrocarbon accumulation and fluid mobility in the investigated *** samples(s.a.e and carbonate)obtained from depths>200 m within the study location have shown bitumen *** geochemistry data of the Rio Bonito Formation s.a.e beds suggest they are potential hydrocarbon source rocks.a.d could have contributed to the gas.a.cumulations within the sandstone *** drilled well data,e.g.,CB-1-sP and TI-1-sP,show hydrocarbon(gas)presence based on the typical resistivity and the combined neutron-density responses.a. depths up to 3400 m,indicating the possibility of other hydrocarbon members.a.art from the heavy oil(bitumen)observed from the near-surface rocks *** the three-dimensional(3-D)model,the free fluid indicator(FFI)is more significant towards the southwest and southeast of the area with deeper depths of occurrence,indicating portions with reasonable hydrocarbon recovery rates.a.d good prospects for CO_(2)injection,circulation and permanent ***,future studies based on contemporary datasets.a.e required to es.a.lish the hydrocarbon viability further,foster gas production events.a.d enhance CO_(2)storage possibilities within the region.

关键词： ParanáBasin Hydrocarbon indication sandstone reservoirs Rio Bonito Formation CO_(2)storage Hydrocarbon recovery factor Fluid injection rate

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sedimentary characteristics.a.d lithofacies paleogeography of the Cambrian in sichuan basin, southwest China

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petroleum 2024年第2期10卷 224-242页

作者： Lin Xie Xuefei Yang Yanhong Zhang Yan Xu Deming Zeng Ruifeng Tang Yao Du Xingzhi Wang s.a.e Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum University school of Geoscience and Technology Southwest Petroleum University schlumberger China s.a. Res.a.ch Institute of Exploration and Development PetroChina Southwest Oil & Gas Field Company

Cambrian in sichuan basin developed thick black s.a.e, varies carbonate and clastic rock, which deposited in different sedimentary environment. sichuan basin in the upper Yangtze platform contained a record of environment during the Cambrian. Detail facies.a.alyses of Cambrian enable us to discuss the sedimentary environment and palaeogeographic setting. sedimentation commenced in the Early Cambrian with the deposition of shelf facies(Qiongzhusi Formation and Canglangpu Formation). At this s.a.e, thick s.a.e and clastic rock deposited in sichuan basin. At the end of the Early Cambrian, a carbonate platform developed in upper Yangtze platform, and sichuan basin was located in restricted platform(Longwangmiao Formation). In the Middle Cambrian, tidal flat and restricted platform developed in sichuan basin(Douposi Formation), because of continuous regression. During the Late Cambrian,sichuan basin was located in carbonate platform again(Xixiangchi Formation). There are three types of sedimentary system in the Cambrian of sichuan basin: clastic sedimentary system, clastics-carbonate mixed sedimentary system and carbonate sedimentary system. Vertically, the basin shows the evolutionary character of clastic-carbonate sedimentary systems. The three sedimentary systems correspond to three “transgression-regression” cycles of the Cambrian. The transgression in the initial period of the Early Cambrian led to the formation of clastic sedimentary system in the Qiongzhusi Formation of Lower Cambrian. The transgression in the later period of the Early Cambrian led to the formation of clasticcarbonate mixed sedimentary system in the Middle-Lower Cambrian. The transgression in the initial period of the Late Cambrian led to the formation of carbonate sedimentary system in the Xixiangchi Formation of Upper Cambrian. With the end of Late sinian continental rifting ended, sichuan basin entered a s.a.le evolutionary s.a.e of the craton basin, while the paleo-land developed in the north

关键词： sichuan basin Cambrian sedimentary characteristics Lithofacies paleogeography

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On the analytical solution of transient friction in channel flows

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Applied Mathematics.a.d Mechanics(English Edition) 2024年第8期45卷 1447-1466页

作者： F.J.GARCíA-GARCíA P.FARINAs.a.VARINO Department of Naval&Industrial Engineering Polytechnic School of EngineeringUniversity of A CorunaCampus Industrial de FerrolFerrol 15403A CorunaSpain Integraciones Técnicas de seguridad S.A.Pol.Ind.Espiritu SantoC/Nobel15Cambre 15650A CorunaSpain

The transient friction in channel mean flows is the sum of two contributions,i.e.,the underlying laminar flow(ULF)and the purely turbulent component(PTC),and the contributions.a.e analyzed separately by theoretical *** is found that,the transient friction may be higher or remarkably lower than that in equal-Reynolds number steady-s.a.e *** universal time cons.a.t for plane-parallel laminar flows is reported,and the role of the time cons.a.t in a turbulent mean flow is *** is shown that the time cons.a.t is related to the turbulence's frozen ***,a study of the logarithmic layer during the transient flow is.a.complished,which shows that the logarithmic layer is destroyed.

关键词： transient friction transient flow unsteady channel flow

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