Pulverized-coal combustion in Wall-Protecting-Jets combustor (WPJC)

A new type of pulverized-coal combustor, called "Wall-Protecting-Jets Combustor" (hereafter, WPJC has been proposed, designed and studied with both CFD (Computational Fluid Dynamics) and experimental methods. The WPJC is based on a novel concept in which all inlet jets are along the combustor wall. Pilot combustion experiments were conducted to investigate the combustion performance of WPJC. Two-phase flows and pulverized-coal combustion were simulated to study the mechanism of),WPJC using the commercial software FLUENT. The results show that the WPJC has many remarkable advantages: wall-protection by the cold jets without the use of refractory materials; low-temperature and three-stage combustion with low NOx emission; negligible ash/slag-deposition; multiple functions with convenient switching between them; effective adjustment of the combustion intensity and the ignition position.

油水分离技术研究之一--直管和螺旋管的数值模拟

本文采用数值模拟的方法研究油水混合物在直管和螺旋管中的流动状况.计算采用Euler-Euler法和Euler模型:支配油水分离两相流动的基本方程包括连续方程和动量方程,湍流模型采用多相流中混合型k-ε模式,基本方程的离散和求解采用SIMPLE算法.利用Fluent软件,以直管和螺旋管为例进行了计算,获得了初步计算结果.计算表明,本文所用方法可以较好地模拟直管中油水在重力作用下的分离,以及螺旋分离器中油水在重力和离心力共同作用下的分离现象.并可为实验研究提供参考。

Combination Of Cfd And Csd Packages For Fluid-Structure Interaction

In this article the UDF script file in the Fluent software was rewritten as the "connecting file" for the Fluent and the ANSYS/ABAQUS in order that the joined file can be used to do aero-elastic computations. In this way the fluid field is computed by solving the Navier-Stokes equations and the structure movement is integrated by the dynamics directly. An analysis of the computed results shows that this coupled method designed for simulating aero-elastic systems is workable and can be used for the other fluid-structure interaction problems.

油水分离技术研究之一——直管和螺旋管的数值模拟

　本文采用数值模拟的方法研究油水混合物在直管和螺旋管中的流动状况。计算采用Euler Euler法和Euler模型:支配油水分离两相流动的基本方程包括连续方程和动量方程,湍流模型采用多相流中混合型k ε模式,基本方程的离散和求解采用SIMPLE算法。利用Fluent软件,以直管和螺旋管为例进行了计算,获得了初步计算结果。计算表明,本文所用方法可以较好地模拟直管中油水在重力作用下的分离,以及螺旋分离器中油水在重力和离心力共同作用下的分离现象。并可为实验研究提供参考。

超音速流动中侧向喷流干扰特性的数值模拟

通过与实验结果的比较验证Fluent软件可以用于超音速流动中侧向喷流干扰特性数值研究．使用Fluent软件对超音速流动中不同喷流压力和攻角下侧向喷流干扰特性进行的数值研究表明，超音速流动中，随喷流压力和负攻角增大，喷流前的高压区明显增大，喷流的控制效果更好．喷流包裹作用的影响范围在90°弹面内．喷流压力增大，喷流包裹作用加强，影响范围增大．

复合式分离器的研究总结与展望

总结了自2001年开始,六年来中国科学院力学研究所在复合式分离器研究方面取得的进展．在工程研究方面,从提出集重力、离心力、膨胀于一体的复合式分离方法开始,采用以实验为主结合数值模拟的研究路线,得到了螺旋管、T型管等主要分离部件的设计准则,然后按工业使用的1／10缩尺比例(体积)设计制造了高效复合式油水分高器实验样机,通过试验,达到了分离后油中含水率小于1%的当代国际先进水平．按相同的油水处理量与国内、国际上的分离器相比,重量可减轻30％左右．目前新制造的直径2．4m长6m的工业样机已在河北霸州的华北油田上进行实际的工业应用试验．在学术研究方面：以液滴沉降的力学模型为基础,用Fluent方法计算了螺旋管中油水两相流动,得到了有小孔质量流出的螺旋管流场,在流出的流量及其组分配比上都与实验结果吻合较好；对国际前沿研究的叉

重力沉降分离的数值模拟

采用商业软件Fluent程序对油水和油砂的重力沉降分离进行了数值模拟,得到了与实验结果吻合较好的多种黏度、不同液滴和砂粒粒径情况下的重力沉降分离结果,尤其是介质中包含多种粒径分布液滴的沉降分离结果。这对于确定油水和油砂重力沉降分离所需的时间和确定分离器容器的尺寸有很好的指导作用。

弯管分离器的数值模拟与设计优化

为了优化设计转炉烟道中弯管分离器结构,利用计算流体力学软件Fluent,对弯管分离器中的气-固两相流进行了数值模拟。采用正交实验工况设计方法、级差分析法和方差分析法,研究了弯管转折角、分离器进出口当量直径比、斯托克斯数等5个因素对于分离效率和压力损失系数的影响。研究表明:5个因素中,斯托克斯数对分离效率有特别显著影响,斯托克斯数越大,分离效率越高。进出口当量直径比对压力损失系数有显著影响,弯管转折角对压力损失系数有一定影响。进出口当量直径比越小,弯管转折角越小,压力损失系数就越小。在模拟结果的基础上,得到了关于分离效率和压力损失系数计算公式。

Recebido e ofertado: a natureza dos hinos na religião do Santo Daime

A proposta do trabalho é investigar a música e sua centralidade nos rituais do Santo Daime ligados ao Centro Eclético da Fluente Luz Universal Raimundo Irineu Serra (CEFLURIS), fundado na década de 1970. A metodologia utilizada é a observação participante nos trabalhos de hinário, presenciados nas igrejas cariocas Céu do Mar e Jardim Praia da Beira-Mar e do conjunto de dez entrevistas em profundidade. Além de um capítulo da descrição do campo e outro com a revisão bibliográfica da literatura antropológica do Santo Daime, a dissertação conta com três capítulos de análise. O primeiro deles é aberto com a revisão de estudos da etnomusicologia para então abordar o ritual de hinário e a relação entre tempo e música na orientação de tarefas específicas durante as cerimônias; o que constrói entre outras coisas, uma nova concepção de realidade devido aos aspectos poético-musicais aliados ao contexto psicotrópico e ritualístico como um todo. No capítulo seguinte se discute a interpretação nativa que descreve a gênese dos hinos religiosos como um recebimento e suas especificidades, contrapostas a uma idéia de composição musical. As falas do grupo sobre a natureza dos pensamentos, sentimentos e a subjetividade, refletem-se nas noções de sagrado e nas diferenciações hierárquicas nos salões das igrejas daimistas, utilizando o conceito de micropolítica dos sentimentos o dialogo é construído desta vez com os estudos da antropologia das emoções. O terceiro capítulo da análise está voltado para uma discussão sobre as situações que envolvem a oferta de hinos em um complexo circuito de dádivas, quando o daimista presenteia outro membro do grupo por intermédio de canções religiosas, ligando o mundo dos espíritos e os homens pelo ato do presentear. Esta etapa do trabalho também é precedida por uma revisão da literatura antropológica, voltada para estudos clássicos sobre a dádiva, destacando-se a discussão da troca como uma gramática. Todas as fases da análise são introduzidas por revisões teóricas e, da forma como o trabalho está estruturado, os temas abordados nos capítulos iniciais são continuamente retomados ao longo das discussões. O argumento central da dissertação é construído sobre as seguintes questões: Qual o espaço ocupado pela música na vida diária dos seguidores da religião do Santo Daime e dentro dos rituais? De que maneira essas canções são como pontes de ligação entre as esferas sagrada e profana? Como as músicas orientam a práxis religiosa e as relações entre os crentes? De que forma os hinos religiosos do Santo Daime são capazes de suscitar e expressar sentimentos específicos? E enfim: como música e sentimento se articulam na conformação deste tipo de experiência religiosa?

Computational mechanisms of sensorimotor control.

In order to generate skilled and efficient actions, the motor system must find solutions to several problems inherent in sensorimotor control, including nonlinearity, nonstationarity, delays, redundancy, uncertainty, and noise. We review these problems and five computational mechanisms that the brain may use to limit their deleterious effects: optimal feedback control, impedance control, predictive control, Bayesian decision theory, and sensorimotor learning. Together, these computational mechanisms allow skilled and fluent sensorimotor behavior.

Powder stream characteristics in cold spray nozzles

The exponential increase of industrial demand in the past two decades has led scientists to the development of alternative technologies for the fast manufacturing of engineering components, aside from standard and time consuming techniques such as casting or forging.Cold Spray (CS) is a newly developed manufacturing technique, based upon the deposition of metal powder on a substrate due to high energy particle impacts. In this process, the powder is accelerated up to considerable speed in a converging-diverging nozzle, typically using air, nitrogen or helium as a carrier gas. Recent developments have demonstrated significant process capabilities, from the building of mold-free 3D shapes made of various metals, to low porosity and corrosion resistant titanium coatings.In CS, the particle stream characteristics during the acceleration process are important in relation to the final geometry of the coating. Experimental studies have shown the tendency of particles to spread over the nozzle acceleration channel, resulting in a wide exit stream and in the difficulty of producing narrow tracks.This paper presents an investigation on the powder stream characteristics in CS supersonic nozzles. The powder insertion location was varied within the carrier gas flow, along with the geometry of the powder injector, in order to identify their relation with particle trajectories. Computational Fluid Dynamics (CFD) results by Fluent v6.3.26 are presented, along with experimental observations. Different configurations were tested and modeled, giving deposited track geometries of copper and tin ranging from 1. mm to 8. mm in width on metal and polymer substrates. © 2011 Elsevier B.V.

A validation of commercial flow solver performance on hybridised octree meshes

In recent years we have been developing a meshing system which is aimed at eliminating the bottleneck represented by building meshes for real-world, complex turbomachinery configurations. This system is based on a rapid octree meshing technology which is then made conformal to the bodies present. The objective of this paper is to demonstrate that this class of mesh is not only very fast to produce but also fit-for-purpose in the sense that simulations generated with third-party commercial flow solvers like Fluent have the same accuracy as those performed on more conventional meshes. A range of standard examples and test cases will be presented. Copyright © 2011 by ASME.

迷宫流道转角对灌水器水力性能的影响

为研究齿形、梯形以及矩形流道转角变化对水力性能的影响,采用Fluent软件对不同形状下不同转角的流道进行了数值模拟。研究结果表明:当其他条件相同时,转角的变化与流量系数、流态指数呈负相关,其变化对梯形流道灌水器的流量系数影响最大,最多下降了19.03%,齿形流道次之,下降了10.14%,矩形流道是梯形流道转角角度增加的延伸,具有相同的水力性能变化规律;随着角度的增加,梯形流道总的局部水头损失系数最多增加了32.5%,而齿形流道总的局部水头损失系数最多增加了23.4%,变化都很明显;压力较高时,摩阻系数基本保持不变,流体为紊流状态。

利用力致分子动力学模拟方法构建剪切流场

<正>在传统计算力学的研究领域,利用Fluent等软件实现连续介质流体的模拟,已有很成熟的经验及范例;同时,分子动力学模拟也在其擅长的微观结构分析及预测领域有了长足的发展。但是到目前为止,连续介质力学仍无法和分子动力学方法有机地结合起来。因此,仍无法在分子动力学模拟体系构建理想的(即速度梯度和温度可控的)剪切流场。Grattona与Delgado-Buscalioni等的研究表明,在分子动力学模拟中,利用

动网格技术在非稳态空化流计算中的应用

该文基于对钝锥头航行体的空化流动的实验观测, 利用商业软件FLUENT~[1]考核了分块网格模型对降低动网格方法误差影响、提高空化流计算精度的可行性和有效性. 通过与实验的对比表明, 采用分块网格模型能够使基于动网格方法的非稳态空化流计算很好的捕捉到空泡生长, 回射, 翻卷, 脱落, 溃灭这一过程, 并获得较为准确的航行体的运动轨迹和所受的水动力. 进而分析了流场涡结构与空泡演化的机理