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Master equation and runaway speed of the francis turbine

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Journal of Hydrodynamics 2018年第2期30卷 203-217页

作者： zh.zhang free Researcher Zurich Switzerland

The master equation of the francis turbine is derived based on the combination of the angular momentum（Euler） and the energy laws. It relates the geometrical design of the impeller and the regulation settings（guide vane angle and rotational speed） to the discharge and the power output. The master equation, thus, enables the complete characteristics of a given francis turbine to be easily computed. While applying the energy law, both the shock loss at the impeller inlet and the swirling loss at the impeller exit are taken into account. These are main losses which occur at both the partial load and the overloads and, thus, dominantly influence the characteristics of the francis turbine. They also totally govern the discharge of the water through the impeller when the impeller is found in the standstill. The computations have been performed for the discharge, the hydraulic torque and the hydraulic efficiency. They were also compared with the available measurements on a model turbine. Excellent agreement has been achieved. The computations also enable the runaway speed of the francis turbine and the related discharge to be determined as a function of the setting angle of the guide vanes.

关键词： francis turbine master equation runaway speed hydraulic efficiency shock loss swirling loss streamline similarity method

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Journal of Hydrodynamics 2018年第1期30卷 140-152页

作者： zh.zhang free Researcher Zurich Switzerland

An analytical method is presented, which enables the non-uniform velocity and pressure distributions at the impeller inlet of a pump to be accurately computed. The analyses are based on the potential flow theory and the geometrical similarity of the streamline distribution along the leading edge of the impeller blades. The method is thus called streamline similarity method（SSM）. The obtained geometrical form of the flow distribution is then simply described by the geometrical variable G（s） and the first structural constant G_Ⅰ. As clearly demonstrated and also validated by experiments, both the flow velocity and the pressure distributions at the impeller inlet are usually highly non-uniform. This knowledge is indispensible for impeller blade designs to fulfill the shockless inlet flow condition. by introducing the second structural constant G_Ⅱ, the paper also presents the simple and accurate computation of the shock loss, which occurs at the impeller inlet. The introduction of two structural constants contributes immensely to the enhancement of the computational accuracies. As further indicated, all computations presented in this paper can also be well applied to the non-uniform exit flow out of an impeller of the francis turbine for accurately computing the related mean values.

关键词： Pumps streamline similarity method flow distribution shock loss structural constant

Nonlinear Analysis of Pile foundation Jacket Platform

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China Ocean Engineering 1997年第1期12卷 21-28页

作者： Xu, b Shen, zh Institute of Mechanics Chinese Academy of Sciences Beijing 100080 China

In this paper, the nonlinear collapse of the bOHAI-8 pile foundation jacket platform has been analyzed. The ultimate load and collapse process of two computational models of the structure are given. One model is of fixed support whose length is eight times the pile leg diameter and the other considers the nonlinearity of the soil-pile interaction.

关键词： nonlinear analysis jacket platform ultimate load platform collapse

DEVELOPMENT　Of　DISTILLATE　HDS　CATALyST

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催化学报 1996年第5期17卷 401-403页

作者： zhang Kongyuan zh ResearchinstituteofQiluPetrochemicalCompany Zibo25 ResearchinstituteofQiluPetroc

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ＤＥＶＥＬＯＰＭＥＮＴＯＦＤＩＳＴＩＬＬＡＴＥＨＤＳＣＡＴＡＬＹＳＴＺｈａｎｇＫｏｎｇｙｕａｎ，ＺｈｏｕＲａｎ，ＺｈｅｎｇＳｈａｏｋｕａｎ，ＭａｏＰｅｎｇｓｈｅｎｇ（ＲｅｓｅａｒｃｈＩｎｓｔｉｔｕｔｅｏｆＱｉｌｕＰｅｔｒｏｃｈｅｍｉｃａｌＣｏｍｐａｎ...

关键词：发展馏出液加氢脱硫过程催化剂氧化铝氧化钼氧化钴热解汽油改性剂

Constructive proof on the existence of periodic solution of Duffing equation

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Chinese Science bulletin 1997年第22期42卷 1870-1874页

作者： Li, WG Shen, zh Nanjing univ Dept Math Nanjing 210093 Peoples R China

CONSIDER the following boundary value problem of Duffing equation:{x(t)+Cx’(t)+g(t,x)=e(t), x(0)-x’(zπ)=x’(0)-x’(2π)=0,} (1)where g: R×R→R is continuous and continuously differentiable with respect to x, continu-ous and 2π-periodic with respect to t. C is a constant. e: R→R is continuous and 2π-period-ic. If there exist two almost everywhere continuous functions a(t), b(t)

关键词： Duffing equation periodic solution continuation.

Inflow and outflow permeability tests in a very soft clay under low stresses

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第8期16卷 3270-3283页

作者： J.W.S.Vargas f.A.b.Danziger f.R.Lopes T.Lunne federal university of Rio de Janeiro Rio de JaneiroBrazil Norwegian Geotechnical Institute OsloNorway

In situ inflow and outflow permeability tests with the bAT probe at SarapuíII soft clay test site are presented.A description of the bAT permeability test is provided,discussing its advantages and shortcomings,especially in the case of very soft clays under low *** pressures were monitored during probe installation and were found to be slightly lower than piezocone u2 pore pressures,consistent with the position of the *** role of filter tip saturation was investigated after the usual saturation procedure provided an unsatisfactory pore pressure response during probe *** show that the vacuum saturation procedure provides adequate response during installation and increases the reliability of the coefficient of permeability determination in early *** inflow and outflow tests yielded similar results,indicating that careful execution of the test can lead to good test repeatability regardless of the loading *** sequences of alternated inflow and outflow tests have yielded similar results,indicating that soil reconsolidation and filter clogging were negligible in the tests *** are presented concerning the relationship between index parameters and the in situ coefficient of permeability for SarapuíII clay,which plot outside the range of existing databases.

关键词： Permeability test Soft clay bAT probe Inflow and outflow tests

Protein-activated atomic layer deposition for robust crude-oil-repellent hierarchical nano-armored membranes

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Science bulletin 2024年第2期69卷 218-226页

作者： Xiaobin yang Pan Sun yajie Wen Anil u.Mane Jeffrey W.Elam Jun Ma Shaomin Liu Seth b.Darling Lu Shao MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage State Key Laboratory of Urban Water Resource and EnvironmentSchool of Chemistry and Chemical EngineeringHarbin Institute of TechnologyHarbin 150001China Chemical Sciences and Engineering Division Argonne National LaboratoryLemont IL 60439USA Applied Materials Division Argonne National LaboratoryLemont IL 60439USA Advanced Materials for Energy-Water Systems Energy frontier Research Center Argonne National LaboratoryLemont IL 60439USA Pritzker School of Molecular Engineering University of ChicagoChicago IL 60637USA Department of Physics University of Ilinois at ChicagoChicago IL 60607USA School of Environment Harbin Institute of TechnologyHarbin 150090China WA School of Mines:Minerals Energy and Chemical EngineeringCurtin UniversityPerth WA 6845Australia

Atomic layer deposition(ALD)offers unique capabilities to fabricate atomically engineered porous materials with precise pore tuning and multi-functionalization for diverse applications like advanced membrane separations towards sustainable energy-water ***,current ALD technique is inhibited on most non-polar polymeric membranes due to lack of accessible nucleation ***,we report a facile method to efficiently promote ALD coating on hydrophobic surface of polymeric membranes via novel protein activation/*** a proof of concept,TiO2 ALD-coated membranes activated by bovine serum albumin exhibit remarkable superhydrophilicity,ultralow underwater crude oil adhesion,and robust tolerance to rigorous environments including acid,alkali,saline,and *** importantly,excellent cyclable crude oil-in-water emulsion separation performance can be *** mechanism for activation/sensitization is rooted in reactivity for a particular set of amino ***,the universality of protein-sensitized ALD is demonstrated using common egg white,promising numerous potential usages in biomedical engineering,environmental remediation,lowcarbon manufacturing,catalysis,and beyond.

关键词： Membrane separation Atomic layer deposition Water treatment Antifouling

Synthesis and Crystal Structure of Trans-bis(acesulfamato-O)tetraaquazinc(Ⅱ)

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Chinese Journal of Structural Chemistry 2010年第7期29卷 1047-1050页

作者： SAHIN Onur ICbuDAK Hasan b(u|¨)y(u|¨)KG(u|¨)ng(O|¨)R Orhan Department of Physics Faculty of Arts and SciencesOndokuz Mayis UniversitySamsunTurkey Department of Chemistry Faculty of Arts and SciencesOndokuz Mayis UniversitySamsunTurkey

The title compound, trans-bis（acesulfamato-O）tetraaquazinc（Ⅱ）（I, C8H16N2O12S2Zn）, crystallizes in the triclinic system, space group P1 with a = 5.1638（5）, b = 8.5338（9）, c = 9.9583（9）A, α = 74.325（8）, β = 81.112（7）, γ = 75.800（8）°, V= 407.77（7） A3, Z = 1, f（000） = 236, Rint = 0.085, T= 296 K, the final R = 0.029 and wR = 0.078 for 1832 observed reflections with I〉 2σ（0. The ZnⅡcentre resides on a centre of symmetry and has a distorted octahedral geometry. The basal plane is defined by two carbonyl O atoms of two monodentate trans-oriented acesulfamato ligands and two trans-aqua ligands. The axial positions in the octahedron are occupied by two trans-aqua ligands. Intermolecular O-H…O hydrogen bonds produce R22（8） and R22（16） rings, which lead to two- dimensional polymeric chains.

关键词： crystal structure zinc(Ⅱ) octahedral complex hydrogen bonds

Studies on Thermal Conductivity of Diamond film

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High Technology Letters 1995年第1期1卷 91-94页

作者： Jingbiao, C. Hong, Ch. Jifa, zh. Dayan, b. Rongchuan, f. univ of Science and Technology of China Hefei China

Diamond films were prepared by electron-assisted chemical vapor deposition (EACVD) system, and the thermal diffusivities of the films with or without substrate were studied by use of photothermal deflection (PTD) technique. The results show that less non-diamond component and larger crystalline size result in higher thermal conductivity of CVD diamond film. The influence of substrate on the measurement of thermal conductivity of the film was investigated, and a simple two-layer heat conduction model is given to account for the influence and used to draw the thermal conductivity of the film from the effective thermal diffusivity of film/substrate system.

关键词： Diamond film Photothermal deflection Thermal conductivity Substrate