The Torsional Vibration of Turbo Axis Induced by Unsteady Aerodynamic Force on Rotor blade

INTRoDUCTIONThestructuralfailureofturbotalsbytorsionalvibrationisoneofthemostimPortantproblemsthect-ingthesafetyoftheturbomachineryoperation-Inthepasttime,researchesonthecauseofthetorsionalvibrationofturboaxishavebeenfocusedonelectricalandmechanicalfields(D.Lambrecht,1982.H.DikenandI.G.Tadjbakhsh,1989.IEEEWorkingGroupInterimReport,l982).Butasafluidmachinerystea-mturbinemayexperienceintensetorsionalvibrationin-ducedbyfluid.Thisphenomenonissimilartotheflutterinsofarasbothoftheminvolve…     

Average Droplet Diameter Measurement and Results for Fuel Aerosol Injected by Certain Types of the Turbojet Burners

INTRODUCTIONMeasurementofthedropletdiameteroffuelaerosolisverydifficult,becauseofthefastchangeofitssize,whichiscausedbyevaporationandassociation.Itisalsoverydifficulttogetaknowledgeofaerosolstreamsinthecourseofconstructionofnewtypeoffuelburn-ersanddiagnosticprocessaswell.Diffractionmethodisoneofthemostusefulmea-suringproceduresinthiscase.Thedropletsizeofmonodispersivemediumiseasytorecognise.Analy-sisofadiffeactionpatternofpolydispersivemediumisconsiderablymoredifficult.Thisworkpresentsam…     

提升反应温度对微尺度火焰稳定性的改善

本实验对微尺度燃烧器内部使用电热丝向反应物加热,提高其温度,减少散热影响,从而实现微尺度火焰稳燃.燃烧器为石英直圆管,长82.mm,通流面积3.33.mm2.氢气/空气混合气体流量为0.12.L/min、0.2.L/min、0.4.L/min,电热功率分别为0.W、1.05.W4、.70.W.实验结果显示,提高电热功率抑制熄火;提升燃料混合气体总流量也有助于抑制熄火;但高流量同时带来吹脱问题.测量燃烧器壁面温度,结合数值模拟研究内部燃烧过程.结果显示,随电热功率上升,反应温度和OH质量分数上升,证明电加热强化反应,抑制了热熄火.比较壁面散热,电热功率0.W,流量由0.12.L/min上升到0.2.L/min时,壁面散热占总能量份额由84.8%降低至81.1%.因此,在一定范围内提升燃料流量亦可抑制热熄火.     

参考文献格式要求

正1.参考文献按正文部分标注的序号依次列出,并在序号中加[]。2.对于常见的各类参考文献标注方法如下:1)著作:作者姓名,题名[M].出版地:出版者,出版年.2)期刊论文:作者姓名.题名[J].期刊名称,年,卷(期):页码.3)会议论文集:作者姓名.题名[C]//论文集名称,会议地点,会议日期.4)学位论文:作者姓名.题名[D].出版地:出版者,出版年.5)专利文献:专利申请者或所有者姓名.专利题名.专利国别.专利号[P].公告日期或公开日期.获取路径.6)电子文献:作者姓名.题名[文献类型标志(含文献载体标志)见其它].出版地:出版者,出版年(更新或修改日期),获取路径.7)报告:作者姓名.题名[R].出版地:出版者,出版年.     

近期地热文摘

D84710 扩充地热规划（ Geothermal ProjectOutreach, Laurie Maclenahan and Curtis Williams, GRC Bulletin, Vol. 34. No. 1. Jan./Feb.2005,23-26 ）；D84711 50年地热生涯谈勘探（A Strange Brecd of Cat, Carl F. Austin, GRC Bulletin, Vol.34 ,No. 1 ,Jan./Feb. 2005,27-29 ）；D84712 示踪剂试验分析的系统方法（A Systematic Method An Alternative Tracer Test Analysis Using Beowawe Data, G. Michael Shook,GRC Bulletion, Vol. 34. No. 1. Jan./Feb. 2005,31-35 ）；D84713可再生能源能帮助重建天然气市场平衡吗？（ Can Renewable Energy Help？ Restoring Equilibrium to Natural Gas Markets, Ryan Wiser and Mark Bolinger, GRC Bulletin, Vol. 34.No. 1 Jan./Feb. 2005,37-39 ）；D84714 注入低温流体诱发的热弹性提高与破碎渗透性的效果及其实验室验证（Thermoelastically-induced Fracture Permeability Enhance-ment Associated With Cold Fluid Injection andits Laboratory Verification, 伊藤高敏、渡边恒、Daniel Swenson、林一夫，日本地热学会蒜。Vol．27．No．2（2005），101—113）；……     

铝活塞耐磨镶圈(续篇Ⅱ)

2　耐磨镶圈的设计2 1　单环槽耐磨镶圈的设计(如表1)表1活塞直径(mm)活塞环高度(mm)<2 .5 >2 .5～4.0 >4.0～5 .0 >5 .0～6.5<12 5<12 5 ,<15 02 .02 .5 52 .5 53 .23 .24.04.05 .1C .环槽最大深度K .环槽最大宽度(梯形环槽时取最大值)B .环槽后面厚度,一般取0 .5C ,但最小不得小于2 1mmT .环岸宽度,根据活塞直径及环槽宽度决定A .活塞环岸直径加7.5mmE .台阶直径,A -4 .5 7mmF .耐磨镶圈内径D -2B -2Cα.斜面角度,3°3 0′或7°3 0′G .计算得出H .定位台阶宽度1/ 2 (K +T +T) ,最小2mmR .圆弧角半径,根据环槽后面厚度决定,从2 …     

Flow Visualization and Topological Analysis of a Turbine Rotor Cascade with Tip Clearance

INTRoDUCTIoNRecentlysignificantattentionhasbeengiventothefinestructurewithintheflowfieldofturbomachinery.Ingeneral,thestudyofthisproblemcontainstwoas-pects.Thefirstistovisualizethesolidsurfaceflowandtopologicallyanalyzethesingularpointstoinves-tigatetheirnumbers,typesandlocationsandtheskinfrictionlinepatternsintheflowfie1dnearesttothewall.Thisaspectaimsatobtainingacertainamountofwallflowinformation.Thesecondaspect,ontheotherhand,carriesoutdetailedflowfieldmeasure-mentsandvisualizationstoac…     

几种参考文献的书写格式

正(其中空格、标点符号、字母照写)连续出版物:[标引序号]作者.文题[J].刊名,年,卷(期):起始页码一终止页码.专著:[标引序号]作者.书名[M].出版地:出版者,出版年.译著:[标引序号]作者.书名[M].译者.出版地:出版者,出版年.论文集:[标引序号]作者.文题[A].编者.文集[C].出版地:出版者,出版年.起始一     

The Second—Order Imaginary Plane Method and Its Calculation Accuracy

INTRODUCTIONMathematicalmodelingarebecondngmoreandmorepopularintheindustrialresearchfield.Theseavailablenumericaltoolsarenowusedbyresearchersasthebasisoflargemathematicalmodelswhicharemadeincreasinglysophisticatedinordertoreflecttheactualphenomenaascloselyaspossible.How-ever'thecomplekitiesofmostindustrialprocesses,togetherwithlongcomputationtimerequiremellt,stillprecludearigoroussimulationofthephenom-enainvolved.Affordablesolutionsareobtainedonlytliroughsimpunedmethods.Thaditionally,the…     

Effect of Guide Vanes on the Performance of a Variable Chord Self—Rectifying Air Turbine

INTRODUCTIONWiththeconventionalenergyresourceslikelytogetexhaustedinafewdecades,theinexhaustiblesourcesofenergyhavetotaketheirplace.Alternateenergyfromtheoceanisattractingtheattelltionoftheresearchersinrecentyearsduetoitsperennialavailabilityandminimumhealthhazards.Ofthemanypossibleformsofoceanenergy,waveenergyispromising.Waveenergyisanalternateformenergy,whichispollutantfreeandinnearfutureitislikelytobeeconomicallyviable.Countrieswhicharesurroundedbyseaandpossessremotelysituatedislandcom…     

Non-Darcian effects on natural convection heat transfer in a wavy porous enclosure

A numerical investigation is carried out to analyze natural convection heat transfer inside a cavity with a sinusoidal vertical wavy wall and filled with a porous medium. The vertical walls are isothermal while the top and bottom horizontal straight walls are kept adiabatic. The transport equations are solved using the finite element formulation based on the Galerkin method of weighted residuals. The validity of the numerical code used is ascertained by comparing our results with previously published results. The importance of non-Darcian effects on convection in a wavy porous cavity is analyzed in this work. Different flow models for porous media such, as Brinkman-extended Darcy, Forchheimer-extended Darcy, and the generalized flow models, are considered. Results are presented in terms of streamlines, isotherms, and local heat transfer. The implications of Rayleigh number, number of wavy surface undulation and amplitude of the wavy surface on the flow structure and heat transfer characteristics are investigated in detail while the Prandtl number is considered equal to unity.     

叶轮机械内部二次流计算分析方法

为了研究叶轮机械内部复杂的旋涡结构,提出了一种新的二次流计算方法。叶轮机械内部复杂的旋涡结构通过二次流矢量描绘出来,并与Q准则进行对比。另外,对本文提出的二次流计算方法进行了扇形试验研究。结果表明:利用本文计算方法所获得的二次流分布与Q准则具有良好的对应关系,识别旋涡结构的位置时两者判断是一致的。所以,可以较好地描绘出叶轮机械内部的旋涡结构。     

Irreversibility analysis for Casson thermo-fluidics inside a cone: Cattaneo–Christov heat flux

In this communication, thermodynamic irreversibility arising in dissipative Casson fluid flow inside a cone is investigated. The boundary–layer flow is considered wherein the motion is caused due to a point sink at the cone's vertex and the movement of the wall of the cone. The wall of the cone is subjected to mass transpiration that alters the flow and thermal regime. The cone having fluid-saturated porous medium experiences Cattaneo–Christov heat flux. The configuration admits a similarity transformation that yields a boundary value problem (BVP) comprising an ordinary differential equation. The BVP is treated by the fourth-order R-K method along with the shooting algorithm. The system yields a dual solution for momentum and energy, which gives rise to a dual regime for entropy distribution. Numerical computations provide quantities of interest viz. velocity and temperature distributions, skin friction coefficient, Nusselt number, and entropy distribution. Phenomena exhibited through profiles/tables for velocity, temperature, entropy, streamlines, and other quantities of interest reveal interesting results.     

涡轮导叶轴向弯曲对其气动性能影响的研究_三维粘流数值分析

近年来计算流体力学在叶轮机械中得了应用,在三维计算方法有了很大的进。与之同时,从学院式的研究到工业应用的过渡已经开始。中国科学院工程热物理研究所在最近二十年内致力于发展各种轮机械三维流动的计算方法。本文的目的是介绍作者的方法和应用它来研究分析一个典型的大长径比涡轮导向器气流流动的物理现象。本文给出了一些研究结果和建议。     

基于神经网络＆NURBS技术的叶片优化设计研究

应用流行的神经网络技术与先进的几何描述方法NURBS技术，对某两级风扇进行优化改型设计，特别针对于转子2的根部截面进行优化，通过对优化前后的转子2以及两级风扇的流场气动结构与特性的对比分析表明，该优化设计方法确实可行，具有一定的先进性，能够改善叶轮机械的整体气动特性，可以为叶轮机械的优化设计提供一种新的途径。     

Flow visualization of Rayleigh–Bénard convection for cubical cavity

Natural convective flow of air inside the cubical cavity is investigated numerically. The temperature of the bottom wall is kept higher than that of top cold wall, and other four walls are assumed to be adiabatic. Attention has been paid to the convective discretization schemes, like upwind, QUICK, total variation diminishing, normalized variable diagram (NVD) schemes that are compared with respect to accuracy. The output is validated with respect to the results available in the literature. A parallel computing message passing interface code is adapted to run the simulations. From the results, it is observed that the NVD scheme gives better results among all the employed convective discretization schemes irrespective of the mesh structure. Thus, in this article, self filtered central differencing which is a family of NVD, is used. From the enormous output data, along with the streamlines, contours of isotherms, the new technique of energy pathlines, and field synergy are used to visualize the fluid flow and heat transfer mechanism arising in the system in the range of Ra from 10³ to 10⁶. Free energy streamlines are observed with small Ra, whereas trapped energy streamlines are observed with high Ra. When Ra increases, synergy angle increases and implies that the synergy between the velocity vector and temperature gradient gets reduced and leads to increasing values of average Nusselt number (Nu).     

低速环形压气机静叶栅采用弯叶片壁面分离流结构的数值分析

使用拓扑结构分析方法对某型压气机静叶栅的直叶片与弯叶片数值计算，对壁面分离流结构进行了分析研究，发现弯叶片对壁面流线拓扑结构和分离流结构影响明显。给出了直叶栅吸力面，下端壁角区流场的拓扑结构，并证明数值计算结果的奇点总数满足环形叶栅壁面（包括叶片表面和上、下端壁表面）拓扑准则。图10参4     

集群计算机系统用于叶轮机械通流部分全三维设计分析

探讨了集群计算机系统用于叶轮机械通流部分设计的重要意义和可行性，发展了一整套基于微机集群计算机系统的、独具特色的叶轮机械通流部分全三维粘性流动的分析方法，研发了完全具有我国自主知识产权、程序可靠的叶轮机械流场特性分析软件包。     

Mixed convective flow in a bottom heated lid‐driven cubical cavity: Energy streamlines and field synergy

Analysis of three dimensional natural convective lid‐driven cavity flow is carried out numerically. The top wall is assumed to slide in its own plane at a constant speed. Isothermal temperature is maintained at horizontal walls in which the bottom wall is assumed to be at a higher temperature than the top wall. Governing equations of this problem, expressed in dimensionless form are solved by using the finite volume method. Numerical results are computed for the control parameters arising in the system, namely, the Reynolds number (Re) and Richardson number (Ri) in the range of 100 ≤ Re ≤ 1000 and 0.001 ≤ Ri ≤ 10. The contours of isotherms, streamlines, Vortex corelines, energy pathlines, and field synergy are used to visualize the flow and thermal characteristics. The simulated results are corroborated with those available in the literature. When Re = 100 and 400 with growth of Ri there are "free" energy streamlines and they exhibited symmetric nature near the boundaries. The participation of convective thermal energy and kinetic energy is insignificant compared to conductive thermal energy, where the velocity components are modest. When Re = 1000 with increase of Ri, "trapped" energy streamlines are detected. Energy streamlines occupy substantial part. This is due to the result of high Re, with increasing Ri, kinetic energy and convective thermal energy get dominated and hence "trapped" streamlines formed. As Re increases, synergy angle increases for distinct Ri values. So the synergy between temperature and velocity gets worse. The synergy angle of buoyant‐aiding flow is high while the buoyant‐opposing flow is significantly less than that of forced convection flow when Ri = 1. This gives the relation between temperature field and velocity at buoyant‐aiding flow, which is at the worst situation leading to increasing average Nusselt number.     

Heatline method for the visualization of natural convection in a complicated cavity

In this paper, natural convection inside a two-dimensional cavity with a wavy right vertical wall has been carried out. The bottom wall is heated by a spatially varying temperature and other three walls are kept at constant lower temperature. The integral forms of the governing equations are solved numerically using finite-volume method in non-orthogonal body-fitted coordinate system. SIMPLE algorithm with higher-order upwinding scheme are used. The method of numerical visualization of heat transport for convective heat transfer by heatlines is studied. The heatfunction equation in the transformed plane is solved in terms of dimensionless variables. Results are presented in the form of streamlines, isotherms, heatlines, local and average Nusselt number distribution for a selected range of Rayleigh number (10⁰–10⁶). The results are presented for three different undulations (1–3) with different wave amplitude (0.00–0.10) and a fluid having Prandtl number 0.71.