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Numerical Simulation of the Tip Aerodynamics and Acoustics Test

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Journal of Thermal Science 2016年第2期25卷 153-160页

作者： F Tejero e P Doerffer o Szulc J l Cross The Szwalski Institute of Fluid-Flow Machinery Polish Academy of Sciences. Fiszera 14 80-231 Gdansk Poland NASA Ames Research Center (retired) Moffett Field CA USA

The application of an efficient flow control system on helicopter rotor blades may lead to improved aerodynamic performance. Recently, our invention of Rod Vortex Generators(RVGs) has been analyzed for helicopter rotor blades in hover with success. As a step forward, the study has been extended to forward flight conditions. For this reason, a validation of the numerical mode.l.ng for a reference helicopter rotor(without flow control) is needed. The article presents a study of the flow-field of the AH-1G helicopter rotor in low-, medium- and high-speed forward flight. The CFD code FloWer from DlR has proven to be a suitable tool for the aerodynamic analysis of the two-bladed rotor without any artificial wake mode.l.ng. It solves the URANS equations with leA(linear explicit Algebraic stress) k-ω model using the chimera ove.l.pping grids technique. Validation of the numerical model uses comparison with the detailed flight test data gathered by Cross J. l. and Watts M. e. during the Tip Aerodynamics and Acoustics Test(TAAT) conducted at NASA in 1981. Satisfactory agreements for all speed regimes and a presence of significant flow separation in high-speed forward flight suggest a possible benefit from the future implementation of RVGs. The numerical results based on the URANS approach are presented not only for a popular, low-speed case commonly used in rotorcraft community for CFD codes validation but preferably for medium- and high-speed test conditions that have not been published to date.

关键词： AH-1G TAAT helicopter rotor forward flight chimera ove.l.pping grid

Combustion characteristics of low-quality lignite for different bed material sphericities in a circulating fluidized bed boiler:A numerical study

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Particuology 2024年第7期90卷 364-382页

作者： barış Gürel Gülşah Karaca Dolgun osman İpek Ali Keçebaş Department of Mechanical engineering Engineering FacultySüleyman Demirel UniversityÇünürIspartaTurkey Department of energy Systems engineering Technology FacultyMuğla SıtkıKoçman UniversityKötekliMenteşeMuğlaTurkey

This study delves into the combustion behavior of various lignite types within a circulating fluidized bed boiler(CFBB),with a primary focus on the impact of different bed material sphericity ratios(0.5,0.7,and 0.9).Utilizing bed material with a sphericity ratio of 0.9 sourced from theÇan power plant and verified through experimentation,the research reve.l. several key ***,furnace temperatures tended to rise with higher sphericity ratios,albeit with variations between lignite types,particularly highlighting the complexity of this relationship in the case of GlI-Tunçbilek *** levels in the combustion chamber remained consistent across different sphericity ratios,indicating minimal influence on pressure *** combustion efficiency,especially at the bottom of the boiler,was observed at lower sphericity levels(0.5 and 0.7)forÇan lignite,as re.l.cted in Co_(2) mole *** No_(x) emissions generally decreased with lower sphericity,the sensitivity to sphericity varied by lignite type,with Ilgın lignite showcasing low No_(x) but high So_(2) emissions,underscoring the intricate interplay between lignite properties,sphericity,and ***,this study advances our understanding of CFBB combustion dynamics,offering insights valuable for optimizing performance and emissions control,particularly in lignite-based power.

关键词： Circulating fluidized bed boiler Computational particle fluid dynamics method Particle sphericity ratios No_(x)and So_(2)emissions energy production efficiency

Influence of flooding and vegetation on carbon,nitrogen,and phosphorus dynamics in the pore water of a Spartina alterniflora salt marsh

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Journal of environmental Sciences 2011年第2期23卷 212-221页

作者： Vanesa l.Negrin Carla V.Spetter Raúl o.Asteasuain Gerardo M.e.Perillo Jorge e.Marcovecchio Argentine Institute of oceanography (IADo CONICETCCT-Bahía Blanca)Camino La Carrindanga km 75Building E-1 CC 804Bahía Blanca 8000Argentina Department of Chemistry Southern National Institute of Chemistry (INQUISUR)Southern National University (UNS)Av Alem 1253Bahía Blanca 8000Argentina Department of Ge.l.gy Southern National University (UNS)San Juan 670Bahía Blanca 8000Argentina National Technological University Regional Faculty of Bahía Blanca (UTN-FRBB)11 de Abril 461Bahía Blanca 8000Argentina University of the Fraternity of Associations Santo Toms de Aquino (FASTA) Gascón 3145Mar del Plata 7600Argentina

Four sites were selected in a salt marsh in the Bahia Blanca estuary （Argentina）：（1） low marsh （flooded by the tide twice daily） vegetated by S. alterniflora; （2） non-vegetated low marsh; （3） high marsh （flooded only in spring tides） vegetated by S. alterniflora; （4） non-vegetated high marsh. The pH and eh were measured in sediments, while dissolved nutrients （ammonium, nitrate, nitrite and phosphate） and particulate organic matter （PoM） were determined in pore water, pH （6.2-8.7） was only affected by vegetation in low areas. eh （from -300 to 250 mV） was lower at low sites than at high ones; in the.l.tter, the values were higher in the non-vegetated sediments. The PoM concentration was greater in the high marsh than in the.l.w marsh, with no effect of vegetation. Ammonium was the most abundant nitrogen nutrient species in pore water, except in the non-vegetated high marsh where nitrate concentration was higher. All nitrogen nutrients were affected by both flooding and vegetation. Phosphate was always present in pore water at all sites throughout the year and its concentration varied within narrow limits, with no effect of flooding and greater values always at non-vegetated sites. our results showed that the variability of the pore water composition within the marsh is greater than the temporal variation, meaning that both tidal flooding and vegetation are important in the dynamics of nutrients and organic matter in the sediment pore water.

关键词： organic matter nutrients flooding Spartina alterniflora

Safety evaluation of Amphora sp.,a marine microalgal diatom isolated from the Cape coastal waters,South Africa

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Food Bioscience 2023年第3期53卷 941-948页

作者： l.Beekrum e.o.Amonsou J.J.Me.l.m Department of Biotechnology and Food Science Durban University of TechnologySteve Biko RoadBerea4000South Africa

Recent studies have highlighted the huge potential of a marine diatom,Amphora *** an affordable food supplement with significant therapeutic activities,however,the safety of the microalgae for human consumption has not been ***,in this study the in vitro and in vivo toxicity profiles of Amphora *** as we.l.as its extracts were investigated to facilitate its use in human *** in vitro toxicity profile was assessed through the brine shrimp lethality,cytotoxicity and mutagenicity assays while the in vivo study was carried out using a rat *** microalgal extracts displayed no cytotoxicity on the PBMC and MCF-7 ce.l.lines neither did it display any evidence of mutagenicity on the Salmone.l. typhimurium ***,results from the acute toxicity assessment demonstrated no remarkable changes in body and organ weights,the biochemical parameters as we.l.as in the histopathology of the murine.l.ver,heart and ***,it was recorded that the oral administration of Amphora *** a dosage.l.vel of 4000 mg/kg/BW was relatively non-toxic,thus providing a scientific basis for selecting a safe dose in future studies aimed at highlighting the potentials of the diatom in human nutrition.

关键词： dosage coastal selecting

Tio_2在Al_2o_3表面上分散状态的AeM研究

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物理化学学报 1990年第4期6卷 474-479页

作者：魏昭彬辛勤 Sham e.l. Grange P. Delwon B. 中国科学院大连化学物理研究所比利时新鲁汶天主教大学

本文运用AeM方法考察了制备技术对Tio_2在Al_2o_3表面分散状态的影响.发现嫁接法可使Tio_2非常均匀地分散在Al_2o_3表面上,浸渍法也能得到较为均匀的Tio_2分布,而沉淀法所得到的Tio_2分散度较差.Tio_3只聚集在Al_20_3表面上的局部区域。

关键词：二氧化钛分散态 Al2o3表面 AeM

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牛虻

PHASeS　AND　STRUCTURe　oF　PReFoRM　DURING　PRePARING　PRoCeSS　oF　Al／TiCp　CoMPoSITeS　BY　DIReCT　ReACTIoN　SYNTHeSIS

2018年

作者： e. l. Voynich[]

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Acta Metallurgica Sinica(english letters) 1996年第6期9卷 545-548页

作者： S. Y Zeng B. Yang and e.l. Zhang(Harbin Institute of Technology, Harbin 150001, China)M.Z. Ma(Jiamusi University, Jiamusi 154002, China ) Harbin Inst of Technology Harbin China

Direct reaction synthesis(DRS), based on the principle of self-propagating hightemperature synthesis (SHS), is a new method for preparing particulate metal matrix composites (PMMCs). The effects of the temperature of the aluminum melt and the aluminum content in the preform on the phases and structure of the reacted preform have been investigated by X-ray diffraction and scanning electron *** has been shown that TiC phase is prone to be synthesized with the increasing of the temperature of the aluminum melt and the decreasing of the aluminum powder content in the preform, and that the size of TiC particle becomes fine with the increasing of the temperature and the decreasing of the aluminum powder content.

关键词： direct reaction synthesis particulate composite Al/TiC

提高农产品的利用减少粮食供应不足——食品科学与技术在应对全球粮食供应不足中的适度贡献

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中国食品学报 2009年第6期9卷 1-9页

作者： Walter e.l. Spiess 德国卡尔斯鲁厄工业大学德国卡尔斯鲁厄76131

世界约六分之一的人口遭受严重的饥饿和营养不良的危害。遭受饥饿的热点地区并非均匀地分布在全球各地，其中非洲最严重!但在东南亚、中美洲、南美洲甚至在诸如欧洲和美国的许多地区也同样有人遭受饥饿。

关键词：粮食供应科学与技术农产品食品营养不良饥饿非均匀东南亚

The presence and partitioning behavior of flame retardants in waste.l.achate,and air particles from Norwegian waste-handling facilities

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Journal of environmental Sciences 2017年第12期29卷 115-132页

作者： Nicolas A.o.Morin Patrik l.Andersson Sarah e.Hale Hans Peter H.Arp Norwegian Geotechnical Institute(NGI) P.O.Box 3930Ulleval StadionN-0806 OsloNorway environmental and Food laboratory of Vendee.l.A V) Department of ChemistryRond-point Georges Dural CS 8080285021 La Roche-sur-YonFrance Chemistry Department Umed UniversitySE-901 87 UmeaSweden

Flame retardants in commercial products eventually make their way into the waste *** the presence of flame retardants in Norwegian landfills, incineration facilities and recycling sorting/defragmenting facilities is investigated. These facilities handled waste electrical and electronic equipment（Weee）, vehicles, digestate, glass, combustibles, bottom ash and fly ash. The flame retardants considered included polybrominated diphenyl ethers（∑BDe-10） as we.l.as dechlorane plus, polybrominated biphenyls, hexabromobenzene,pentabromotoluene and pentabromoethylbenzene（collectively referred to as ∑FR-7）. Plastic,Weee and vehicles contained the.l.rgest amount of flame retardants（∑BDe-10： 45,000–210,000 μg/kg; ∑FR-7： 300–13,000 μg/kg）. It was hypothesized leachate and air concentrations from facilities that sort/defragment Weee and vehicles would be the highest. This was supported for total air phase concentrations（∑BDe-10： 9000–195,000 pg/m^3 Weee/vehicle facilities, 80–900 pg/m^3 in incineration/sorting and landfill sites）, but not for water leachate concentrations（e.g., ∑BDe-10： 15–3500 ng/l in Weee/Vehicle facilities and 1–250 ng/l in landfill sites）. landfill leachate exhibited similar concentrations as Weee/vehicle sorting and defragmenting facility leachate. To better account for concentrations in leachates at the different facilities, waste-water partitioning coefficients, Kwastewere measured（for the first time to our knowledge for flame retardants）. Weee and plastic waste had elevated Kwastecompared to other wastes, likely because flame retardants are directly added to these materials. The results of this study have implications for the development of strategies to reduce exposure and environmental emissions of flame retardants in waste and recycled products through improved waste management practices.

关键词： Brominated flame retardants Waste management environmental emissions Atmospheric emissions Partitioning leachate