查询词典 vortex flow

Secondly, three kinds of mathematics model of optical vortex beams were introduced here. Then the propagation dynamics of optical vortex beams through the non-axis symmetry system is studied, this chapter includes the introduction of the symmetry vortex beam and the non- symmetry vortex beam, the deduction of the Collins diffract integral formula for the non-axis symmetry system, and the transformation of the vortex beam passing through the non-axis symmetry system has been described by using the numerical simulation. Then the general calculation for the orbit momentum of vortex beams, the matrix form for the orbit momentum of vortex beams, and the photon method to describe the orbit momentum of vortex beams are also introduced here. Finally, the interference about optical vortex beams was studied.

本文对涡旋光束进行了较为全面的介绍和研究，主要内容包括：（1）光学涡旋光束的基本理论，主要是介绍了单个光学涡旋光束在柱坐标中的一些表征，涡旋光束的奇异相位和光学涡旋的相位结构；（2）光学涡旋光束的三种数学模型；（3）光学涡旋光束在非轴对称光学系统中的传播动力学，其中介绍了对称涡旋光束与非对称涡旋光束，推导了非轴对称光学系统的 Collins 衍射积分公式，并利用计算机模拟图描述了对称涡旋光束经过非轴对称光学系统后涡旋形态的改变；（4）涡旋光束轨道角动量的一般计算，涡旋光束轨道角动量的矩阵形式，光子法描述涡旋的轨道角动量；（5）涡旋光束的干涉。

It is indicated that this loss will not change with the increase of the Reynolds number but the intensity of the passage vortex increases with the decrease of the Reynolds number. The tip leakage flow will weaken with the increase of the passage vortex because of the interaction between the passage vortex and the tip leakage vortex, and the position of the tip leakage vortex is more close to the middle of the passage. In addition, the distributions of the total pressure loss and the flow angle at the exit of the cascade are influenced by the intensity and the position of the tip leakage vortex.

结果表明：对于间隙存在造成的流动损失，数值模拟结果与实验结果及 Denton的预测值都十分接近，基本上不随着雷诺数的变化而变化；但是，随着雷诺数的减小，通道涡增强；间隙泄漏涡在和通道涡的相互作用中，强度减弱，在叶栅出口处的位置更加靠近中叶展；出口处的总压损失和气流角的分布也由于间隙泄漏涡强度和位置的变化而发生改变。

The structure of this article is as follows: Firstly, the background of this article is stated in exordia and the question was raised; chapter one stated cash flow management theory and transnational corporations' cash flow management characters; chapter two introduced general cash flow management technical and method; chapter three analysis cash flow management situation of Chinese transnational corporations; chapter four take VW as an example to expatiate company situation and the impact to cash flow management by the organization of the company, the goal of cash flow management and financing strategy, then introduce the cash flow forecast module, at last analysis the experience and disadvantage of VW's cash flow management; Chapter five give some suggestions to Chinese local transnational corporations for cash flow management including: using proper cash flow management technical and establish scientific process, ect.; the last part is the conclusion This article took VW's cash flow management as an example to descried transnational corporation cash flow management theory and practical issues, but some techniques can only be used in some country where can exchange currency freely; it can not be practical in some foreign exchange administration countries including China, such kind of cash flow module still under discussion based on theory.

本文结构如下：首先在绪言部分简述了选题背景，提出了问题；之后，第一章陈述了现金流管理理论和跨国公司现金流管理的特点；第二章评述了国际常见的现金流管理技术和方法；第三章分析了中国跨国公司的现金流管理现状；第四章详细阐述了VW公司现金流管理的实例，包括公司的发展及组织架构设置对现金流管理的影响，公司现金流管理的目标、筹资策略等，重点介绍了VW公司的现金流预测模型，最后分析了VW公司现金流管理的经验和不足；第五章详细阐述了对中国跨国公司现金流管理的建议，包括应用适合的现金流管理技术及建立科学的现金流管理流程等；最后在结论部分对该文做了总结。

By constructing a generalized function"helical solitary vortex function", the paper solves the stream function of the helical vortex tube with the help of vortex filament one, and obtains some analytical expressions for large single-vortex core and small multi-vortex core.

通过构造一类特殊的广义函数&螺旋孤涡函数&，解决了利用涡丝流函数求(来源：75AB67C论文网www.abclunwen.com)解涡管流函数问题，导出了大单和小多螺旋涡管流函数的解析解。

In chapter 1, an up to now synthetically evaluation is given on the research ways and conclusions about jet in cross-flow. Considering the shortage of previous research ways and techniques (the instantaneous flow field and vortices field can not be properly get), in addition to the deficiency of corresponding conclusion (mainly concentrate on the analysis of time-average but little on structures of flow and action of vortex), the research way and content is draft out in this part. Though PIV, the time-average, instantaneous flow field and vortices field can be get, that will unveil the coherent vortex and its course of generation, development and evolvement, with the assistance of K-ε model and Hybrid Finite Analytic Method , which will proof-test the experiment result and bring some complementary, more profound research about the 3-D characters can be done. Using some fundamental topological theory and principle on flow analysis, with anglicizing of vortex structure, a reasonable description is the topological characteristic of near field in JICF given.

首先在第一章中对横流中湍射流的以往研究方法和研究成果给予了综合的评述，针对横流中湍射流旋涡结构以往研究中研究方法的局限性（不能很好得到流动的瞬态流场及涡量场）和相应研究成果中存在的不足（大都集中在时均特性的分析，对流动的内部结构和旋涡的运动阐述很少），明确了本文的研究方法和研究内容：通过PIV流动测量显示技术得到流动的时均及瞬态流场、涡量场，来揭示横流中湍射流的时均、瞬态流场、涡量分布特性，和各种具有拟序结构性质的复杂涡系的产生、发展及演化过程；结合湍流k-ε双方程模型及相应的HFAM计算方法，对于实验进行相互验证和补充，从而更为充分地研究各种旋涡的三维特性；利用拓扑分析的一些基本原理及相关规则，依据对各种旋涡结构的分析，做出对射流近区流场拓扑性质的合理描述。

Test and analysis show that, the distribution patterns of the tangent veloctiy fields in the big cone area and the small cone area, which are comprised of para-free vortex and para-forced vortex, are basically identical without a change of the radius of the boundary surface; with the increase of the angle of the small cone, the para-free vortex area decreases and the para-forced vortex area increases, and the emulsifiability of the fluid drips increases with the increase of velocity gradient; the tangent velocity increases with the increase of inlet flow, and the maximum tangent velocities of both the big cone area and the small cone area are 4.94 times of the inlet flow; and the maximum tangent velocity increases with the increase of the split ratio and with the radius of the boundary surface not changed.

试验分析表明，大锥段和小锥段切向速度分布规律基本相同，均由准自由涡和准强制涡构成，分界面半径rm没有变化；随着小锥角θ的增加，准自由涡区缩小，准强制涡区扩大，速度梯度增加会加大液滴的乳化程度；随入口流量增加，切向速度增大，经拟合得出大锥段和小锥段的最大切向速度均为入口流量的4.94倍；分流比加大，分界面半径基本不变，最大切向速度增加。

Based on analysis of the current state of the flow pattern modeling abroad and at home, explains the meaning of the mathematical simulation of the flows in the valve.(2) Comparing flow simulation data of jet pump with its experimental one, the feasibility and reliability of FLUENT used for flow simulation are proved.(3) Based on the characteristic of valves, the fluid field analysis of specific ring-spray type flow-adjustable is finished. The valve structure is optimized to meet the need, which makes it have such advantages:(1)smaller vortex area and faintish vortex intensity, so the vibration of vortex is controlled effectively;(2)the pressure is distributed more equality, the transition area is larger.

论文的主要内容包括：(1)简述了阀门研究的现状与发展，在分析与总结国内外流体流动模拟研究的基础上，探讨开展阀门内水流运动数值模拟的意义；(2)对特定型号的射流泵进行了内部流场的数值模拟研究，并与实验数据相比较，验证了应用Fluent进行数值模拟的可行性和可靠性；(3)针对调流阀的特点，对特大口径环喷式流量调节阀进行流场计算，其设计指导思想如下： 1、控制旋涡，减小旋涡区，减小涡的强度； 2、控制压力分布，使阀体受力更均匀，改善局部应力状态，提高阀门使用的安全性； 3、最小绝对压力高于水的汽化压力，不产生汽蚀。

It is available to carry out numerical simulation and fluid dynamic analysis further. Based on Frozen-Rotor Approach and Rotor-Stator Approach, the numerical simulation was carried out in the centrifugal pump and the numerical results showed that the flow in the impeller and volute of centrifugal pump is periodically unsteady. Due to the interaction between impeller and volute the flow is characterized by pressure fluctuations and it is the strongest at impeller outlet and at the vicinity of the tongue. The unsteady pressure fluctuations are also one of the most important reasons to induce vibration and noise. Secondly, the flow field of the volute is characteristic of the vortex flow, and the vortex flow presents very complicated developing process which is creating, increasing and dissipating every now and then. All these lead to very large flow loss in the volute.

采用Frozen-Rotor冻结转子模式和Rotor-Stator滑移界面模式系统开展了不同工况下离心泵内叶轮与蜗壳耦合的定常和非定常流动研究，结果表明由于叶轮与蜗壳的干扰蜗壳进口周向流动的不均匀性是非常强烈的，特别是叶轮与蜗舌间的相互干扰最为强烈，一直影响到叶轮进口和蜗壳扩散管出口的流场；在蜗壳内整个流动是以旋涡形式向出口推进的，并随着包角的变化旋涡表现出十分复杂的产生、发展和耗散的演化过程，导致蜗壳内较大的流动损失。

This thesis deals with oil-water flow rate measurement using a venturi and develops a differential pressure-based two-phase flow rate measurement model, which does a terrific job with the use of a water fraction device. Meanwhile, Coriolis flow rate meter is also studied in the oil-water two-phase flow measurement and a SVM-based single-phase flow rate prediction method is proposed, realizing the prediction of single-phase flow rates. To overcome the disadvantages of both venturi and Coriolis flow meters, a double parameter measurement method is put forward, which combines the two meters and solves the problem of oil-water flow rate measurement. Last but not least, on the basis of the study of two-phase flow, a device for the separation of gas and liquid is designed and realizes the flow rate measurement of three-phase flow as oil, gas and water.

本文对文丘里管测量油水两相流流量进行了研究，建立了基于差压法的两相流流量测量模型，如果与含水率计相结合，可以较好的实现油水两相流的流量测量；同时研究了Coriolis流量计在油水两相流流量测量中的应用，提出了基于SVM的油水两相流分相流量预测方法，实现了油水分相质量流量的预测；针对文丘里管和Coriolis测量油水两相流存在的问题，提出了文丘里管和Coriolis流量计相结合的双参数测量方法，并实现了油水两相流的流量测量；最后，在对油水两相流研究的基础上，设计完成了一种气液分离装置，实现了油气水三相流的流量测量。

First, the typhoon flow field is decomposed into two parts: the maximum asymmetric vortex and irrotational environmental flow field. Then the maximum asymmetric vortex is also decomposed into two parts: the maximum symmetric vortex and β-gyres. Finally, typhoon Pearl(2006) is simulated by WRF model(weather research and forcasting model), and flow fields at various times at 500hPa...

首先，将台风的流场分解成最大的、不对称的涡旋流场和无旋流场；然后将不对称的涡旋流场分解成最大的对称涡旋和不对称的β涡旋对；最后，利用WRF(weather research and forcasting)模式(V2.1.2)模拟了200601号珍珠台风，并对各时次的500hPa风场用该方法进行分解，结果表明：该方法对台风的运动机理研究和实际的台风路径预测提供了有价值的信息。

The production moved off-Broadway to New York City, where she won the Joseph E. Calloway award for her performance, and was profiled in American Theater Magazine as one of ten young theater artists to watch.

生产提出过百老汇的新的纽约市，在那里她赢得了约瑟夫calloway奖，她的表现，并于异型在美国的战区杂志之一， 10战区的青年艺术家观赏。

It's a risk tradeoff, and I believe that adding test support code usually wins.

这是一个风险的权衡，我相信添加测试代码通常会占上风。