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链篦机-回转窑系统回转窑传热过程的数值模拟的开题报告一、研究背景回转窑作为一种重要的干燥设备，在建材、冶金、化工等行业得到广泛应用。
回转窑通过其独特的结构和回转方式，在实现物料热力学过程的同时，使得物料得到良好的混合和自我混合，从而提高了反应速率和产率。
然而，在实际应用中，回转窑中的传热问题一直是一个难点。
回转窑的传热机制是一个复杂的物理过程，不仅涉及传热与传质的过程，同时包含明和暗辐射，地面和物料之间的传热，以及燃烧产物和物料之间的传热等多个方面。
基于此，本文将以链篦机-回转窑系统为出发点，通过数值模拟的方式，深入研究回转窑传热机理及影响因素，为进一步提高回转窑传热效率和优化设计提供参考。
二、研究内容1. 安装数值模拟软件，建立链篦机-回转窑传热数学模型；2. 分析回转窑内传热过程的影响因素，包括物料的性质、流态、速度等参数，燃烧产物温度、浓度等因素；3. 通过数值模拟，深入研究回转窑内和链篦机之间的传热机制和传热规律；4. 对传热过程中的热能损失、传热效率等相关问题进行探讨；5. 参考相关文献，对模拟结果进行验证和应用，以进一步提高链篦机-回转窑系统的传热效率。
三、研究方法1. 建立链篦机-回转窑传热数学模型，使用计算机辅助工程分析软件（例如MATLAB、ANSYS等）进行分析；2. 采用计算流体动力学（CFD）方法，以对流、传热、辐射传热、物料流动等为基础的计算模式模拟系统的传热过程；3. 通过数值模拟和实验验证相结合的方式，进一步优化模型，以获得更准确和全面的结果。
四、研究意义1. 提高链篦机-回转窑系统的传热效率，降低能源消耗，减少运营成本；2. 探究回转窑内传热规律和热媒体流动机制，为改进炉内结构、设计更高效的传热系统提供理论基础；3. 为实现绿色环保、高效节能的工业生产模式提供参考。
五、研究进度安排1. 文献调研：3周；2. 数值模拟软件安装和数学模型建立：2周；3. 模型验证和参数确定：4周；4. 数值模拟和结果分析：4周；5. 结果讨论和总结出论：3周；6. 论文撰写和答辩准备：4周。
大电流稀土电解槽的优化分析王海辉;逄启寿【摘要】Aiming at the problems of low current efficiency and constant consumption of cathode in electrolysis process. Taking the 15kA electrolytic cell as the research object, the cathode diameter of the cell and different cathode insertion depths were simulated by using COMSOL Multiphysics multi physical field coupling software. Obtained the three dimensional electric field and current density distribution of different cathode diameters and different cathode insertion depths, and analyzed the simulation results. The results show that the best electrolytic cell cathode diameter is 65mm, and the best insertion depths of the cathode is about 500mm. According to the conclusion of the study, the optimum insertion depth and cathode diameter of the 15kA rare earth cell can be determined, which can provide reference for the structure optimization of the electrolytic cell.%针对电解过程中电流效率低和阴极不断被消耗等问题,以15 kA稀土电解槽为研究对象,采用COMSOL Multip-hysics多物理场耦合软件对电解槽的不同阴极直径和不同插入深度进行了数值模拟,得出了不同阴极直径和不同阴极插入深度下的三维电场图和电流密度分布曲线图,并对结果进行分析研究,分析得出了稀土电解槽的最佳阴极直径为65 mm,最佳的阴极插入深度为500mm.根据研究结论能够确定15kA稀土电解槽的最佳插入深度与阴极直径,为电解槽的的结构优化提供了参考依据.【期刊名称】《机械设计与制造》【年(卷),期】2017(000)009【总页数】3页(P77-79)【关键词】稀土电解槽;阴极直径;插入深度;数值模拟【作者】王海辉;逄启寿【作者单位】江西理工大学机电工程学院,江西赣州 341000;江西理工大学机电工程学院,江西赣州 341000【正文语种】中文【中图分类】TH16;TF845.6稀土金属及其合金因其独特的性能而被广泛应用于冶金、石油化工、玻璃陶瓷、荧光和电子材料工业、军事等领域[1]。
基于大涡模拟方法的多层动网格技术识别平板气动参数刘祖军;葛耀君;杨泳昕【摘要】Based on Fluent software redevelopment, the motion of a structure was described with UDF and moving grids were also used to realize fluid-solid coupling from view of a loosely coupled model. A new method of multi-moving grid technique was proposed to resolve problems of structure movement restricted by fluid mesh size and calculation failure caused by large deformation of grids under the condition that the velocity of dynamic meshes was in conformity with the space conservation law . In hydrodynamic calculations, the method of large eddy simulation was used to solve N-S equation in order to consider the impact of turbulence. Numerical simulation of flow field around a single degree of freedom forced vibration plate was given. Its aerodynamic parameteis were acquired by fitting aerodynamic time-history curves with the least-square method. The results were in better agreement with Thodorsen theoretic solutions.%从弱耦合的角度出发,对流体计算软件fluent进行二次开发,利用其用户自定义函数(UDF)描述结构的运动状态并结合动网格技术实现流固耦合.在保证动网格运动速度符合空间守恒法则的条件下,针对固体模型在流场中运动受网格尺寸限制且易造成网格变形过大导致计算失败的问题提出了多层动网格的解决方法.流体动力计算时考虑湍流的作用,采用大涡模拟方法求解N-S方程.数值模拟了平板做单自由度强迫振动的断面绕流流场,通过最小二乘法拟合气动力时程曲线获得气动导数.仿真结果与通过Theodorsen理论导出的平板气动导数具有良好的一致性.【期刊名称】《振动与冲击》【年(卷),期】2011(030)004【总页数】5页(P156-160)【关键词】多层动网格;大涡模拟;气动参数;UDF;流固耦合;空间守恒法则【作者】刘祖军;葛耀君;杨泳昕【作者单位】同济大学,桥梁工程系,上海200092;同济大学,桥梁工程系,上海200092;同济大学,桥梁工程系,上海200092【正文语种】中文【中图分类】U441目前桥梁风工程中的气动导数一般通过风洞节段模型试验来获得，采用的方法主要有自由振动法和强迫振动法。
水动力学研究与进展A辑2015年第3期304与相关试验结果的比较验证了计算方法的可靠性，研究了不同影响要素对尾部空泡的影响，得出如下几点结论：(1)航行体离开发射筒后，其尾部空泡由尾空泡和筒口气团两部分所组成。
在初始高压影响下，筒口气团先膨胀后收缩，是导致尾空泡压力先降低而后发展到一定阶段拉断的主要要素。
(2)随着航行体不断向水面运动，尾空泡所处的环境压力也不断发生变化。
受到泡内外压差的影响，尾空泡形态不断发生变化，且伴随着膨胀、收缩及脱落等过程，其压力也在环境压力附近振荡性变化。
(3)航行体运行速度、尾部阻力系数、出筒时刻泡压及燃气绝热常数等量对尾空泡压力和形态均有不同程度的影响。
在试验研究尾空泡变化时，需要对上述各量进行准确模拟。
参考文献:[1]CHOU Y S.Axisymmetric cavity flows past slenderbodies of revolution[J].Journal of Hydronautics,1974,8(1):13-18.[2]RATTAYYA J V,BROSSEAU J A,CHISHOLM M A.Potential flow about bodies of revolution with mixedboundary conditions–axial flow[J].Journal of Hydro-nautics,1981,15(1-4):74-80.[3]李杰,鲁传敬.潜射导弹尾部燃气后效建模及数值模拟[J].弹道学报,2009,21(4):6-8.LI Jie,LU Chuan-jing.The model of combustion gasbubble of submarine-launched missile and numerical si-mulation[J].Journal of Ballistics,2009,21(4):6-8. [4]刘志勇,颜开,王宝寿.潜射导弹尾空泡从生成到拉断过程的数值模拟[J].船舶力学,2005,9(1):43-50.LIU Zhi-yong,YAN Kai,WANG Bao-shou.Numericalsimulation of the development process of a trailing ca-vity from generation to separation[J].Journal of ShipMechanics,2005,9(1):43-50.[5]王亚东,袁绪龙,覃东升.导弹水下发射筒口气泡特性研究[J].兵工学报,2011,32(8):991-995.WANG Ya-dong,YUAN Xu-long,QIN Dong-sheng.Research on the outlet cavity features during the launchof submarine launched missile[J].Acta Armamentarii,2011,32(8):991-995.[6]权晓波,燕国军,李岩,等.水下航行体垂直发射尾空泡生成演化过程三维数值研究[J].船舶力学,2014,18(7):739-745.QUAN Xiao-bo,YAN Guo-jun,Li Yan,et al.Three-di-mensional numerical study on the evolution process oftail bubble of underwater vehicle vertical launching[J].Journal of Ship Mechanics,2014,18(7):739-745. [7]王一伟,黄晨光,杜特专,等.航行体有攻角出水全过程数值模拟[J].水动力学研究与进展,A辑,2011,26(1):48-57.WANG Yi-wei,HUANG Chen-guang,DU Te-zhuan,etal.Numerical simulation of a submerged body exitingfrom water with an attack angle[J].Chinese Journal ofHydrodynamics,2011,26(1):48-57.[8]权晓波,李岩,魏海鹏,等.大攻角下轴对称航行体空化流动特性试验研究[J].水动力学研究与进展,A辑,2008,23(6):662-666.QUAN Xiao-bo,LI Yan,WEI Hai-peng,et al.An ex-periment study on cavitation of underwater vehicle’ssurface at large angles of attack[J].Journal of Hydrody-namics,Ser.A,2008,23(6):662-666.[9]魏海鹏,郭凤美,权晓波.潜射导弹表面空化特性研究[J].宇航学报,2007,28(6):1506-1509.WEI Hai-peng,GUO Feng-mei,QUAN Xiao-bo.Cha-racters of SLBMs surface cavitation[J].Journal of As-tronautics,2007,28(6):1506-1509.[10]燕国军,阎君,权晓波,等.水下航行体垂直发射尾部流场数值计算[J].导弹与航天运载技术,2012,3:42-46.YAN Guo-jun,YAN Jun,QUAN Xiao-bo,et al.Nume-rical study on tail flow field of underwater vehicle invertical launching[J].Missiles and Space Vehicles,2012,3:42-46.[11]SINGHAL A K,ATHAVALE M M.Mathematicalbasis and validation of the full cavitation model[J].ASME Journal of Fluids Engineering,2002,124:617-624.[12]LOGVINOVICH G V.Hydrodynamics of flows withfree boundaries[M].New York,USA:Halsted Press,1973.[13]V ASIN A D.The principle of independence of the ca-vity sections expansion(Logvinovich’s Principle)as thebasis for investigation on cavitation flows[C].VKI Spe-cial Course on Supercavitating Flows,Brussels,Belgium,2001.[14]张学伟,张亮,王聪,等.基于Logvinovich独立膨胀原理的超空泡形态计算方法[J].兵工学报,2009,30(3):361-365.ZHANG Xue-wei,ZHANG Liang,WANG Cong,et al.A calculation method for supercavity shape based onthe logvinovich independence principle of the cavity se-ction expansion[J].Acta Armamentarii,2009,30(3):361-365.[15]KIRSCHNER I N.Implementation and extension of。
摘要离心泵由于其结构的独特性，离心泵的综合性能与诸多方面的因素相关，一个具有良好性能的离心泵必然是考虑多方面因素后的综合。
随着计算机技术的发展，CFD数值模拟方法越来越多的应用到产品的辅助设计与性能优化当中，本文主要基于这一方法，以控制变量法为原则，在众多影响离心泵的参数中选取离心泵的几何参数作为研究对象，来探讨其与离心泵综合性能的关系。
对于离心泵的综合性能，本文分为能量特性，空化特性和噪声特性三个主要部分，而选取的叶轮具体几何参数分别为叶片进口冲角、叶片出口安放角、叶片出口宽度、叶片数。
叶轮作为离心泵的能量传输和转化的核心部件，对离心泵性能具有至关重要的-湍影响。
本文能量特性和空化特性的研究主要以叶轮作为主要载体，基于RNGκε流模型，数值模拟了上述几种不同几何参数下的能量特性和空化特性。
结果表明，叶片进口冲角对效率有较大影响，一定范围内的正冲角有利于内部流动分布的改善，但对空化性能影响不显著；叶片出口角和叶片出口宽度相似，均与扬程呈正相关关系，且对空化的影响强于叶片进口冲角；叶片数对空化性能影响较大，属于强影响因素，在一定范围内，叶片数越多则扬程和轴功率越大，效率的变化取决于扬程和轴功率的增幅大小。
研究噪声特性的模型是增加了进口段和蜗壳压水室后的整体模型，出于几何参数变化引起的蜗壳结构的变化因素，本文从噪声源的角度探讨了不同噪声源对离心泵远声场的影响。
结果显示，旋转叶片表面的压力脉动对离心泵的噪声贡献更加显著。
关键词：离心泵；叶轮几何参数；数值模拟；能量特性；空化特性；噪声特性AbstractThe synthesize performance of a centrifugal pump is associated with many factorsbecause of its unique structure. The centrifugal pump with a good performance must beconsidered with various factors. With the development of computer technology, themethod of CFD numerical simulation to applied to the aided design and performanceoptimization of products become more and more popular, common and important. In thispaper, based on this method and the principles of control variable method, choose theimpeller geometrical parameters of centrifugal pump among numerous factors whichinfluence its performance as the research object, to explore its relationship with thecentrifugal pump performance. In this paper, for the performance of a centrifugal pump, itdivided into three parts: energy properties, cavitation characteristics and noisecharacteristics. Impeller geometric parameters include the blade inlet angle of attack,blade outlet angle, blade outlet width, blade number.Impeller as the core component of transmission and transformation of energy has avital influence on performance of a centrifugal pump. In this paper, the research of energyand cavitation characteristics mainly used the impeller as the main carrier, based on -turbulence model and numerical simulation method. The results show that the RNGκεblade inlet angle of attack has a greater effect on impeller efficiency, is within the scope ofa certain angle of attack is helpful for the improvement of the internal flow distribution,but no significant effects on cavitation performance; Blade outlet angle and blade outletwidth is similar, are positively correlated with head relationship, and the effect ofcavitation is stronger than blade inlet angle of attack; Blade number on the cavitationperformance, belongs to the strong influence factors, within a certain range, the moreblade number, the lager head and shaft power, the efficiency changes is depending on thehead and shaft power increasing size.Adding the import part and spiral case to the impeller as the model of noisecharacteristics researching. The article discussed the influence of different noise source onfar sound field of centrifugal pump considering the spiral case changes caused by thechange of impeller geometric parameters. Results show that the pressure pulsation on thesurface of rotor blades as the noise source making a more significant contribution to the noise.Keywords:Centrifugal pump; Impeller geometric parameters; Numerical simulation;Energy characteristics; Cavitation characteristics; Acoustic characteristics目录摘要 (I)Abstract (II)1绪论1.1研究背景与意义 (1)1.2国内外研究现状及文献综述 (2)1.3离心泵水力性能概述 (7)1.4研究内容与思路 (8)1.5小结 (9)2离心泵的设计思路、三维造型及数值模拟2.1初始模型的设计思路 (10)2.2主要设计流程 (10)2.3原始模型的主要参数 (13)2.4离心泵原始模型的数值模拟 (13)2.5小结 (16)3离心泵叶轮几何参数对能量特性的影响3.1离心泵能量特性的表述 (17)3.2叶片进口安放角对离心泵能量特性的影响 (18)3.3离心泵叶片出口角对其能量特性的影响 (21)3.4叶片出口宽度b2对离心泵能量特性的影响 (25)3.5叶片数Z对离心泵能量特性的影响 (29)3.6小结 (32)4离心泵叶轮几何参数对空化特性的影响4.1空化机理以及空化数值模拟方法 (33)4.2叶片几何参数对离心泵空化性能曲线的影响 (34)4.3不同叶片几何参数对应的离心泵叶轮内部空泡分布 (38)4.4小结 (43)5离心泵流动诱导噪声数值分析5.1离心泵诱导噪声数值计算方法与声学方程 (44)5.2流动诱导噪声数值计算 (47)5.3噪声计算结果及后处理 (48)5.4小结 (52)6总结与展望6.1总结 (53)6.2展望 (54)致谢 (56)参考文献 (57)附录1 攻读学位期间发表论文 (62)1绪论1.1研究背景与意义泵是一种广泛用于国民经济各个领域建设的通用流体机械，其主要功能是进行不同形式的能量转换和输运，而离心泵作为泵类产品中最重要的一种产品，它具有需求量大、应用范围广、品种规格多、结构形式多种多样、性能稳定效率高等特点。
基于CFD的潜艇阻力及流场数值计算涂海文;孙江龙【摘要】The article numerically simulated the resistance and flow field of bare submarine body with different appendages and submarine body full-appended with RNG k-e model. And solving solutions with RANS equations. The girds were divided by ICEM CFD of CFD pretreatment software. Through numerical simulation, it obtained the submarine surface pressure distribution and some characteristics of the flow field near appendages. This is further to lay the foundation for optimizing the boat type and analyzing noise of submarine that induced by flow. And resistance contrast verified the reliability of numerical simulation to some degree.%运用雷诺平均N-S方程,使用CFD前处理软件ICEM CFD划分流场网格,采用RNG k-ε湍流模型,实现了对裸潜体、带指挥台围壳艇体、带十字尾翼艇体、全附体潜艇4种模型的阻力及粘性流场的数值模拟.通过数值模拟,得到了潜艇表面压力分布情况和附体附近流场的一些特性,为进一步优化潜艇的艇型和分析潜艇的流噪声打下了基础.而阻力的对比在一定程度上验证了数值模拟的可靠性.【期刊名称】《舰船科学技术》【年(卷),期】2012(034)003【总页数】7页(P19-25)【关键词】潜艇;CFD;RNG k-ε模型;摩擦阻力【作者】涂海文;孙江龙【作者单位】华中科技大学船舶与海洋工程学院,湖北武汉430074;华中科技大学船舶与海洋工程学院,湖北武汉430074【正文语种】中文【中图分类】U674.76;TB5潜艇周围的流场特别是尾流场的流动特性，不仅对潜艇的水动力性能产生直接的影响，而且引发的流动是潜艇水动力噪声的主要来源之一，对潜艇隐蔽性有重要影响。
Numerical Simulation of Flow Field in a Centrifugal Pump with InducerWei Chao 1 Zhong Weicong 2 Zhang Feng 21. College of Astronautics, Northwestern Polytechnical University, Xi’an 710072, China2. Xi’an Aerospace Propulsion Institute, Xi’an 710100, ChinaAbstract: Based on the N-S Equation and the non-structured mesh technology, the 3D steadyincompressible turbulent flow within a centrifugal pump with inducer was simulated. The internalstatic pressure distribution, velocity distribution and the delivery head were obtained. Moreover,cavitation was also analyzed. The numerical results show that cavitation mainly happens at the outeredges of the entrance blades and the roots of the exit blades in the inducer, the hub entrance and theroots of part blades in the centrifugal wheel. It’s found that cavitation is related with the assemblyangle of the inducer and centrifugal wheel. The numerical results agree with the experimental data verywell.Keywords: inducer; centrifugal pump; numerical simulation; cavitation1 IntroductionThe delivery head, mass flux, efficiency and cavitation performance of pump are important for the design of turbopump-fed liquid rocket engine. The prepositive inducer is usually used to improve the cavitation performance of centrifugal pump. In the conventional R&D mode of pump, the relationships of performance parameters and structure are estimated by empirical formulae. As a result, it’s difficult to control the R&D duration and R&D cost. With the development of CFD technology, the parameters, such as velocity, pressure and cavitation degree, can be obtained by numerical simulation method. The method is proved valid and becomes more and more important in the R&D process of pump. The paper simulated the 3D steady incompressible turbulent flow within a centrifugal pump with inducer using CFD method. The internal static pressure distribution, velocity distribution and the delivery head were obtained. Moreover, the cavitation was also analyzed.2 Modeling2.1 Governing equationsIn the paper, the 3D steady incompressible turbulent flow within the centrifugal pump was simulated with the standard ε−k turbulent model. The governing equations are as follows [1-3]: 2.1.1 Continuity equation()0=∂∂+∂∂j ju x t ρρ (1) 2.1.2 Momentum equation()()i i j i i i i j i j i j i j j i F g x u x x u x x p x u x u u x u t −+⎟⎟⎠⎞⎜⎜⎝⎛∂∂∂∂−⎟⎟⎠⎞⎜⎜⎝⎛∂∂∂∂+∂∂+⎟⎟⎠⎞⎜⎜⎝⎛∂∂∂∂=∂∂+∂∂ρμμμρρ32 (2)The turbulence kinetic energy,κ, and its rate of dissipation, ε, are obtained from the following transport equations:ρμκσμμκρκρ−∂∂+∂∂∂∂+∂∂+∂∂=∂∂+∂∂)(])[(ij j i j i t j k t j j i x u x u x u x x x u t (3) κερμεεσμμερερε221)(])[(c x u x u x u k c x x x u ti j j i j i t k t k k k −∂∂+∂∂∂∂+∂∂+∂∂=∂∂+∂∂ (4) The turbulent viscosity,t μ, is computed by combining κand εas follows:εκρμμ2C t = (5) The model constants ,,,μC 1C 2C εσ and εσ have the following default values: ，，，44.1=μC 44.11=C 92.12=C 3.1=εσ，0.1=κσ。
2.2 Discretization of the Governing equationsThe governing equations were discretized by second order upwind scheme. Pressure-velocity coupling wasachieved by using SIMPLE algorithm. In the computation, under-relaxation was used to control the update of computed variables at each iteration.2.3 Mesh generationThe geometry model of the centrifugal pump studied in the paper is shown in figure 1. Aiming at the complex structure of pump, multi-block mesh generation technique was used to make mesh generation easier and improve mesh quality. The basis idea is dividing the complex computational domain into some less irregular subdomains, meshing them separately and then connecting them together. Based on this idea, the pump was divided into three subdomains: inducer, centrifugal wheel and turbine housing. However, the subdomains were still irregular, so unstructured mesh wasadopted. The whole research domain contained 715517 mesh cells and 206303 mesh nodes.Fig.1 Geometry model of the centrifugal pump Fig.2 Mesh superimposed on the computational domain2.4 Boundary ConditionsThe entrance face of the inducer was specified as mass-flow-inlet boundary. The exit of turbine housing was specified as outflow boundary. The wall function method was applied to model the near-wall region. The flow in the inducer and the centrifugal wheel was modeled in the Moving Reference Frame.2.5 Calculation casesT he flowing media of the centrifugal pump is N2O4. Table.1 lists the calculation cases in the paper.Table.1 Calculation casesCalculation cases Flux（L/s）Rotational velocity (r/min) Case 1 119 10000Case 2 127 10000Case 3 133 10000Case 4 144 100003 Results and DiscussionFig.3 shows the static pressure contours of the whole computational domain in case 1. The inducer increases the entrance pressure of the centrifugal wheel, and improves the anti-cavitation capability of the centrifugal pump.Fig.3 Static pressure contours of the whole computational domain (Pa)(a) Static pressure contours (Pa) (b) Velocity contours (m/s)Fig.4 Contours of the inducerFig.4 shows the static pressure and the velocity contours of the inducer in case 1. Obviously, the maximum velocity is located at the outer edges of the entrance blades, where the static pressure is very low. As a result, thelocation is liable to suffer from cavitation. Moreover，for the effect of the pressure difference between the cascade pressure surface and the suction one near the blade exit, the exit of the inducer is another low pressure area liable to suffer from cavitation.(a) Static pressure contours (Pa) (b) Velocity contours (m/s)Fig.5 Contours of the centrifugal wheelFig.5 shows the static pressure and the velocity contours of the centrifugal wheel in case 1.It can be seen that without stator blades, the static pressure distribution of each blade is different from another. The low pressure areas in the centrifugal wheel are mainly located at the hub entrance and the roots of part blades. The former is related to the low pressure area at the exit of the inducer, while the latter is caused by the pressure difference between the cascade pressure surface and the suction surface.In general, when the pressure is lower than the local saturated pressure, cavitation will happen[4]. The areas where the pressure is lower than the local saturated pressure are shown in Fig.6. It is shown that cavitation mainly happens at the following areas: the blade outer edge at the inducer entrance and the blade root at the exit of the inducer, the hub entrance and part blade roots of the centrifugal wheel. It can be seen that the cavitation area in the centrifugal wheel is corresponding to that in the exit part of the inducer in the circumferential direction, which indicates that cavitation is related with the assembly angle of the inducer and centrifugal wheel.(a) The inducer (b) The centrifugal wheelFig.6 Cavitation areas in the pumpD e l i v e r y h e a d (M P a )Flux(L/s)Fig.7 Comparison of the computational delivery heads and the experimental onesThe Fig.7 contrasts the computational and the experimental delivery heads under different cases. As shown in the figure, the delivery head decreases appreciably along with the increase of the flux. Furthermore, the computational delivery head is 10% larger than the experimental one. The main reason is that in the numerical simulation, the motion and fragmentation of the bubbles produced by cavitation as well as the volume loss are neglected, which magnifies the pressurizing capability factitiously.4 Conclusions(1) Cavitation mainly happens at the outer edges of the entrance blades and the roots of the exit blades in the inducer, the hub entrance and the roots of part blades in the centrifugal wheel.(2) The delivery head decreases appreciably along with the increase of the flux. For the motion and fragmentation of the bubbles produced by cavitation as well as the volume loss are neglected in the simulation, the computational delivery head is 10% larger than the experimental one.References1. B.E. Launder and D.B. Spalding. Lectures in Mathematical Models of Turbulence [M]. Academic Press, London, England, 19722. Tao Wenquan. Numerical Heat Transfer [M]. Xi’an Jiaotong University Press, Jun.20013. Wang Fujun. Analysis of Computational Fluid Dynamics [M].Beijing: Tsinghua University Press, 20044. Liu Guoqiu. Theory of Liquid-propellant Rocket Engine [M]. Astronautics Press of China, Jun.1993。
