查询词典 vortex flow

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。

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。

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。

Experiments exposed that the inner flow of tooth space in the micro-channels was proved to be cycled flow after fully development. For the more, low velocity vortex cavities existed in the vertex angle and inner side of bend angle of straight angle micro-channel, while back flow only appeared in the internal side of bend angle of round angle micro-channel. It's easy to take place deposition in the low velocity vortex cavities, which is the main cause of blocking.

试验发现各类微通道齿间内流充分发展后是一种重复性流动，平角微通道顶角和转角内侧存在低速涡旋区，圆角微通道只在转角内侧出现回流，颗粒在低速涡旋区易发生沉积，是造成堵塞的主要原因。

In Chapter 3, we investigate the effect of vortex flow on spiral turbulence.

我们根据前人实验分析了造成这样效果的原因。

Next the discussion in this study, about an ellipse with an angle of attack and two circular cylinders with different diameters in the flow, the aim of this study is investigated for the ability of the present numerical method by solving the suppression of the vortex shedding flow behind the two-cylinder system which was kind of difficult to reach by a Cartesian grid method. In this study, the suppression of the vortex shedding flow is tested to solve a uniform flow past through two different diameter cylindrical in the flow field with Fractional Step Method and Immersed Boundary Method.The numerical method which we investigated is showed that the results of the problem is appropriable in other literatures.

接著探讨流过具攻角之椭圆柱体流场及流过圆柱抑制涡漩逸出之流场，目的是要研究利用控制圆柱来抑制下游涡流的流场行为，本文采用分步法配合内嵌边界法数值解析一均匀流流经两不同直径的圆柱流场，来测试抑制涡流逸出的问题，根据现有的数值结果发现试验运用了合适的方法且得到令人满意的结果。

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。

Similar effect, or vortex flow path, would result were the grooves to be placed on the housing.

类似的效果，或旋涡流动的路径，会导致人的凹槽，以放置在房屋。

In addition, the effect of the performance improvement and the influences on the flow filed due to the installation of flow-guide plate and the vortex generators and the change of outlet position will be investigated by executing a series of numerical simulation and comparison. Also, the optimum design parameters of the flow-guide plate, the vortex generators, and the outlet position will be found respectively.

接著对此集热器之循环水套，分别进行「变更出水口位置」、「加装导流板」以及在导流板上添加「涡流产生器」等一系列的改良设计与流场模拟分析比较，以找出最佳之设计参数组合。

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。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。