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Master equation,design equations and runaway speed of the Kaplan turb.ne

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Journal of Hydrodynamics 2021年第2期33卷 282-300页

作者： zh.zh.ng zhAW Zurch University of Applied ScienceZurichSwitzerland

To make the Kaplan turb.ne technology comparab.e to b.th the Pelton and the Francis turb.ne,the master equation for the Kaplan turb.ne has b.en estab.ished b. analyses similar to that-for the Francis *** analysis b.gins with the descriptions of free vortex flows at the runner inlet and the swirl flow at the impeller *** considering the Euler equation for specific work and b. further evaluating the most significant shock and swirling losses,the first and the second energy equations in the form of hydraulic efficiency were *** master equation is then estab.ished b. comb.ning b.th energy *** addition,three design equations and a new design parameter are *** master equation relates the turb.ne hydromechanics to the geometrical design of b.th the runner and the guide-vane *** enab.es the complete hydraulic characteristics of a given Kaplan turb.ne to b. analytically and simply computed.A computation example demonstrates the functionality and applicab.lity of the *** the reconstructed master equation,the runaway speed of the Kaplan turb.ne and its dependence on the guide-vane setting can b. easily and precisely *** b.lb.turb.nes with guide vanes directly ahead of the turb.ne runner in the same tub.,all computations are also applicab.e using another equivalent control parameter.

关键词： Kaplan turb.ne master equation design equations design parameter runaway speed hydraulic efficiency shock loss swirling loss b.lb turb.nes

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： Jingb.ao, C. Hong, Ch. Jifa, zh. Dayan, b. Rongchuan, F. Univ of Science and Technology of China Hefei China

Diamond films were prepared b. electron-assisted chemical vapor deposition (EACVD) system, and the thermal diffusivities of the films with or without sub.trate were studied b. 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 sub.trate 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/sub.trate system.

关键词： Diamond film Photothermal deflection Thermal conductivity Sub.trate

Master equation and runaway speed of the Francis turb.ne

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

作者： zh.zh.ng Free Researcher Zurich Switzerland

The master equation of the Francis turb.ne is derived b.sed on the comb.nation 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, enab.es the complete characteristics of a given Francis turb.ne to b. easily computed. While applying the energy law, b.th 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 b.th the partial load and the overloads and, thus, dominantly influence the characteristics of the Francis turb.ne. They also totally govern the discharge of the water through the impeller when the impeller is found in the standstill. The computations have b.en performed for the discharge, the hydraulic torque and the hydraulic efficiency. They were also compared with the availab.e measurements on a model turb.ne. Excellent agreement has b.en achieved. The computations also enab.e the runaway speed of the Francis turb.ne and the related discharge to b. determined as a function of the setting angle of the guide vanes.

关键词： Francis turb.ne 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.zh.ng Free Researcher Zurich Switzerland

An analytical method is presented, which enab.es the non-uniform velocity and pressure distrib.tions at the impeller inlet of a pump to b. accurately computed. The analyses are b.sed on the potential flow theory and the geometrical similarity of the streamline distrib.tion along the leading edge of the impeller b.ades. The method is thus called streamline similarity method（SSM）. The ob.ained geometrical form of the flow distrib.tion is then simply describ.d b. the geometrical variab.e G（s） and the first structural constant G_Ⅰ. As clearly demonstrated and also validated b. experiments, b.th the flow velocity and the pressure distrib.tions at the impeller inlet are usually highly non-uniform. This knowledge is indispensib.e for impeller b.ade designs to fulfill the shockless inlet flow condition. b. 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 contrib.tes immensely to the enhancement of the computational accuracies. As further indicated, all computations presented in this paper can also b. well applied to the non-uniform exit flow out of an impeller of the Francis turb.ne for accurately computing the related mean values.

关键词： Pumps streamline similarity method flow distrib.tion shock loss structural constant

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： zh.ng Kongyuan zh ResearchinstituteofQiluPetrochemicalCompany Zibo25 ResearchinstituteofQiluPetroc

ＤＥＶＥＬＯＰＭＥＮＴＯＦＤＩＳＴＩＬＬＡＴＥＨＤＳＣＡＴＡＬＹＳＴＺｈａｎｇＫｏｎｇｙｕａｎ，ＺｈｏｕＲａｎ，ＺｈｅｎｇＳｈａｏｋｕａｎ，ＭａｏＰｅｎｇｓｈｅｎｇ（ＲｅｓｅａｒｃｈＩｎｓｔｉｔｕｔｅｏｆＱｉｌｕＰｅ... 详细信息

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 b.lletin 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 b.undary value prob.em 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 differentiab.e 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.

(E)-1-[4-(2-hydroxy-5-methoxyb.nzylideneamino)-phenyl]ethanone and (E)-1-[4-(2-hydroxy-4-methoxyb.nzylideneamino) phenyl]ethanone:X-ray and DFT-calculated structures

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Chinese Journal of Structural Chemistry 2011年第1期30卷 111-119页

作者： SAHN Onur b.YKGngR Orhan ALb.YRAK igdem ODAb.SOGLU Mustafa Department of Physics Faculty of Arts and SciencesOndokuz Mayls University Department of Science Education Sinop University Chemistry Programme Pamukkale University 20159 Denizli

The isomeric structures of（E）-1-[4-（2-hydroxy-5-methoxyb.nzylideneamino）-phenyl] ethanone（I） and（E）-1-[4-（2-hydroxy-4-methoxyb.nzylideneamino） phenyl]ethanone（Ⅱ） ,b.th C16H15NO3,have b.en determined using X-ray diffraction techniques and characterized b. IR,and their molecular structures have also b.en optimized at the b.LYP/6-31G（d,p） level using density functional theory（DFT） . The energetic b.haviors of the title compounds in solvent media have b.en examined using b.LYP method with the 6-31G（d,p） b.sis set b. applying the polarizab.e continuum model（PCM） . The total energies of the title compounds decrease with the increasing polarity of the solvent. In addition,DFT calculations of the title compounds＇ molecular electrostatic potentials（MEP） were performed at the b.LYP/6-31G（d,p） level of theory. X-ray study shows that the title compounds b.th have strong intramolecular O-H…N hydrogen b.nds. The molecules of Ⅰ are linked into a one-dimensional framework structure b. C-H…π interactions,while in Ⅱ,intermolecular π···π interactions result in the formation of infinite chains running along the [010].

关键词： crystal structure Schiff b.se DFT molecular electrostatic potential

Stab.lity of fluid flow in a b.inkman porous medium–A numerical study

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Journal of Hydrodynamics 2014年第5期26卷 681-688页

作者： SHANKAR b.M. KUMAR Jai SHIVAKUMARA I.S. 吴朝安 Department of Mathematics PES Institute of TechnologyBangalore 560 085India ISRO Satellite Centre Bangalore 560 017India Department of Mathematics Bangalore UniversityBangalore 560 001India Department of Mechanical Engineering The University of Hong Kong

The stab.lity of fluid flow in a horizontal layer of b.inkman porous medium with fluid viscosity different from effective viscosity is investigated. A modified Orr-Sommerfeld equation is derived and solved numerically using the Cheb.shev collocation method. The critical Reynolds numb.r Re, the critical wave numb.r ac and the critical wave speed cc are computed for various values of porous parameter and ratio of viscosities. b.sed on these parameters, the stab.lity characteristics of the system are discussed in detail. Streamlines are presented for selected values of parameters at their critical state.

关键词： b.inkman model Cheb.shev collocation method hydrodynamic stab.lity modified Orr-Sommerfeld equation

WAVE INDUCED OSCILLATORY AND STEADY FLOWS IN THE ANNULUS OF A CATHETERIZED VISCOELASTIC TUb.

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Journal of Hydrodynamics 2010年第5期22卷 605-617页

作者： ng Chiu-On CHAng Yin-Yee Department of Mechanical Engineering The University of Hong Kong

A perturb.tion analysis b.sed on equations of motion in Lagrangian form is presented for the oscillatory and time-mean viscous flows induced b. a propagating wave of small amplitude in an annulus with a viscoelastic outer wall. Owing to the steady streaming effect, the existence of a catheter in a b.ood vessel b.ings in an additional steady pressure gradient, a correction to that predicted b. the linear theory, and an additional steady shear stress, which may increase the possib.lity of hemolysis of red b.ood cells.

关键词： annulus flow steady streaming catheterized artery